Download Evaluating least-cost model predictions with empirical

Evaluating least-cost model predictions with empirical dispersal data: A case-study
using radiotracking data of hedgehogs (Erinaceus europaeus) By: Driezen, Kassandra;
Adriaensen, Frank; Rondinini, Carlo; Doncaster, C. Patrick; Matthysen, Erik.
Ecological Modelling, Dec2007, Vol. 209 Issue 2-4, p314-322, 9p Abstract: Habitat
fragmentation and habitat loss are widely recognized as major threats to biodiversity
on a regional as well as on a global scale. To restrict its effects, ecological networks
such as the trans-European network NATURA2000 are being developed based on the
assumption that structural connections between habitat fragments lead to increased
exchange through dispersal and a higher viability of (meta)populations. However,
there is a great need for techniques that translate these networks and/or structural
characteristics of landscapes into functional connectivity for specific organisms.
Least-cost analysis has the capacities to fulfill these needs, but has never been
validated against actual observations of dispersal paths. Here we present a method to
validate the results of a least-cost analysis by comparing realized movement paths of
hedgehogs in unfamiliar areas, obtained by radiotracking, with statistics on landscapewide distribution of cost values. The degree of correspondence between empirical
dispersal paths and the output of a least-cost analysis can be visualized and quantified,
and least-cost scenarios can be statistically compared. We show that hedgehogs
moved along paths with significantly lower cost values than the average landscape,
implying that they took better than random routes, but performance was relatively
poor. We attribute this to the relatively generalistic habitat use of the model species
and the rather homogeneous landscapes. We conclude that this approach can be useful
for further validation of the least-cost model and allows a direct comparison of model
performance among different taxa and/or landscapes.
Assessing the conservation status of the tiger Panthera tigris at priority sites in
Peninsular Malaysia. By: Lynam, Antony J.; Laidlaw, Ruth; Bennett, Elizabeth L.;
Noordin, Wan Shaharuddin Wan; Elagupillay, Sivananthan. Oryx, Oct2007, Vol. 41
Issue 4, p454-462, 9p, 3 charts, 1 diagram Abstract: Wildlife managers require status
and distribution information for informed decisions. Recognizing the tiger's globally
threatened status and potential as an umbrella species for protection of forested
landscapes, camera trap surveys for tigers and other large mammals have been
conducted since 1997 in Peninsular Malaysia with the aim of assessing the population
status of tigers in the Peninsula. Results from surveys at nine sites between December
1997 and December 1999 are reported here. Tigers were confirmed from six sites in
the Main Range and Greater Taman Negara landscape, with multiple locations inside
putative priority tiger areas. Although the data were collected 8 years ago, they are
supplemented with more recent information, including tiger-human conflict
investigations during 2000-2005 that indicate tiger persistence at these sites. Tiger
density estimates were 0.51-1.95 tigers per 100 km<sup>2</sup>. With results from
other surveys, this suggests a national population of up to several hundred tigers. A
thorough survey, with sufficient resources, should be carried out in the future to
derive a more reliable tiger population estimate for Malaysia. Key threats are habitat
loss and fragmentation, hunting of prey, commercial trade in tiger parts, and
harassment and displacement. Recommendations for the recovery of tigers in
Peninsular Malaysia are provided.
Landscape genetics of Physalaemus cuvieri in Brazilian Cerrado: Correspondence
between population structure and patterns of human occupation and habitat loss
By: Telles, Mariana Pires de Campos; Diniz-Filho, José Alexandre Felizola;
Bastos, Rogério Pereira; Soares, Thannya Nascimento; Guimarães, Lorena
Dall‘Ara; Lima, Leôncio Pedrosa. Biological Conservation, Sep2007, Vol. 139
Issue 1/2, p37-46, 10p Abstract: It is now widely recognized that knowledge on
population genetic structure is important to evaluate population viability and
persistence or to establish conservation priorities. In this context, species that are
locally abundant or widely distributed can be informative on how broad scale
processes of habitat loss and fragmentation, as those caused by intensive human
occupation, affect population genetic structure. In this paper, we analyzed
population genetic structure of Physalaemus cuvieri (Amphibia: Leptodactylidae)
in the core of the Cerrado biome, in the Goiás State, Central Brazil, using RAPD
molecular markers. Local populations are genetically different according to RAPD
markers, and an analysis of molecular variation (AMOVA) revealed a significant
interpopulational variance component around 10%. However, these population
differentiation patterns are not strongly structured in geographic space, and a
Mantel spatial correlogram indicated only a slight significant spatial structure at
short geographic distances. These patterns are expected by the ecological and lifehistory knowledge of the species, leading to a relatively low magnitude of
population differentiation coupled with short distance spatial patterns. Moreover,
even these weak patterns showed a signature of effects of human occupation and
habitat loss on genetic differentiation at regional scale, with discontinuities to
gene flow in two particular regions of the State with more intense habitat loss and
older human settlement.
Terrain use by an expanding brown bear population in relation to age, recreational
resorts and human settlements By: Nellemann, Christian; Støen, Ole-Gunnar;
Kindberg, Jonas; Swenson, Jon E.; Vistnes, Ingunn; Ericsson, Göran; Katajisto,
Jonna; Kaltenborn, Bjørn Petter; Martin, Jodie; Ordiz, Andrés. Biological
Conservation, Aug2007, Vol. 138 Issue 1/2, p157-165, 9p Abstract: Brown bears
(Ursus arctos) are threatened by habitat loss, habitat fragmentation by
infrastructure and human settlements, and have been hunted to local extinction in
large areas of their former range. We analyzed the habitat use during the non
denning period of 106 radio-collared bears in an expanding bear population in
Sweden in relation to resorts and towns, terrain ruggedness, sex and age of bears.
Bear use increased substantially with increasing distance to towns and resorts for
comparable habitat and terrain types, also for independent scat surveys using
DNA-analyses. More than 74% of all female bear locations were in the 29% of the
terrain classified as “rugged” and located >10km from any town or resort, whereas
similar habitat closer to towns or resorts was avoided. Bears closer to larger
settlements and resorts (<10km) were on average 27–51% younger than in areas
beyond (mean 4.4±0.4 versus 8.9±0.8 years for males and 4.4±0.4 versus 6.0±0.2
years for females). Sub-adult bears (<4years) comprised up to 52% of all bear use
within 10km from resorts and settlements, likely representing exploratory
dispersing individuals. These areas, however, contained only 8% of the old males
(>7years), the remaining 92% located beyond 10km from major resorts and
settlements. Recreational resorts are developing rapidly, typically near national
parks, and may thus limit expansion or fragment existing bear habitats. Together
with active conservation, safeguarding undeveloped corridors of forest and rugged
terrain may be important for successful recolonization of the brown bear into its
original range
Human and domestic animal populations as a potential threat to wild carnivore
conservation in a fragmented landscape from the Eastern Brazilian Amazon By:
Whiteman, Christina Wippich; Matushima, Eliana Reiko; Cavalcanti Confalonieri,
Ulisses Eugênio; Palha, Maria das Dores Correia; da Silva, Alanna do Socorro Lima;
Monteiro, Vanessa Conceição. Biological Conservation, Aug2007, Vol. 138 Issue 1/2,
p290-296, 7p Abstract: Hydroelectric projects are one of the well known factors
responsible for habitat loss and fragmentation in the Amazon. The Tucuruí Lake
Protected Area (Tucuruí Lake APA), in the state of Pará, Brazil, Eastern Brazilian
Amazon, is under the influence of the Tucuruí dam. Zones of wildlife protection
(ZWPs), where no human activities should be allowed, were created inside this
protected area. However, human populations and their domestic animals still reside
within the ZWPs. Domestic carnivores have been implicated in wild carnivore
population declines, particularly in Africa, as a consequence of disease transmission,
especially involving the canine distemper virus. This study examined the
seroprevalence of antibodies to this pathogen in domestic dogs from the ZWPs and its
immediate surroundings at the Tucuruí Lake Protected Area, and revealed 27%
seropositivity. Wild carnivore species such as the jaguar (Panthera onca), puma
(Puma concolor), ocelot (Leopardus pardalis), coati (Nasua nasua), among others,
inhabit the ZWPs and information provided by the local community indicates their
close contact with the human and domestic dog populations. Such evidence supports
the concern that relates the presence of the domestic dogs to disease transmission and
conservation risks for wild carnivores in the ZWPs of the Tucuruí Lake APA.
Landscape modification and habitat fragmentation: a synthesis. By: Fischer, Joern;
Lindenmayer, David B.. Global Ecology & Biogeography, May2007, Vol. 16 Issue 3,
p265-280, 16p, 3 charts, 5 diagrams Abstract: Landscape modification and habitat
fragmentation are key drivers of global species loss. Their effects may be understood
by focusing on: (1) individual species and the processes threatening them, and (2)
human-perceived landscape patterns and their correlation with species and
assemblages. Individual species may decline as a result of interacting exogenous and
endogenous threats, including habitat loss, habitat degradation, habitat isolation,
changes in the biology, behaviour, and interactions of species, as well as additional,
stochastic threats. Human-perceived landscape patterns that are frequently correlated
with species assemblages include the amount and structure of native vegetation, the
prevalence of anthropogenic edges, the degree of landscape connectivity, and the
structure and heterogeneity of modified areas. Extinction cascades are particularly
likely to occur in landscapes with low native vegetation cover, low landscape
connectivity, degraded native vegetation and intensive land use in modified areas,
especially if keystone species or entire functional groups of species are lost. This
review (1) demonstrates that species-oriented and pattern-oriented approaches to
understanding the ecology of modified landscapes are highly complementary, (2)
clarifies the links between a wide range of interconnected themes, and (3) provides
clear and consistent terminology. Tangible research and management priorities are
outlined that are likely to benefit the conservation of native species in modified
landscapes around the world. [ABSTRACT FROM AUTHOR]; DOI: 10.1111/j.14668238
Not rare, but threatened: the endemic Madagascar flying fox Pteropus rufus in a
fragmented landscape. By: Jenkins, Richard K. B.; Andriafidison, Daudet;
Razafimanahaka, H. Julie; Rabearivelo, Andriamanana; Razafindrakoto,
Noromampiandra; Ratsimandresy, Zo; Andrianandrasana, Rabe H.; Razafimahatratra,
Emilienne; Racey, Paul A.. Oryx, Apr2007, Vol. 41 Issue 2, p263-271, 9p Abstract:
The endemic Madagascar flying fox Pteropus rufus is threatened by habitat loss at
roost sites and hunting for bushmeat. There is no conservation plan for this species,
even though it is categorized on the IUCN Red List as Vulnerable and plays an
important role as a seed disperser. In the Mangoro valley of central eastern
Madagascar we monitored roost occupancy and abundance of P. rufus on 15
occasions at six sites over a 12-month period and conducted a detailed assessment of
eight roosts during July 2004. There was considerable monthly variation in bat
abundance and only two sites contained bats during every visit. Three sites were
occupied only between September and March and may act as maternity or nursery
roosts. Evidence of hunting was found at three roosts, and fire and forest clearance are
ubiquitous threats. Two roosts were in Eucalyptus plantations and six were in small
(2.2 - 28.7 ha) isolated fragments of degraded, mid elevation dense humid forest. All
roosts were outside protected areas but were within 20 km of relatively intact forest.
Faecal analysis revealed a diet of native forest tree species, cultivated fruits and
Eucalyptus flowers. P. rufus in the Mangoro valley, and elsewhere in Madagascar,
appears to survive in human-impacted environments by the inclusion of exotic plants
in its diet and the ability to move between roosts. We provide conservation
recommendations for P. rufus at both local and national levels. [ABSTRACT FROM
AUTHOR]; DOI: 10.1017/S0030605307001883
Effect of Human Disturbance on Bee Communities in a Forested Ecosystem. By:
WINFREE, RACHAEL; GRISWOLD, TERRY; KREMEN, CLAIRE. Conservation
Biology, Feb2007, Vol. 21 Issue 1, p213-223, 11p, 3 charts, 6 graphs, 1bw Abstract
(English): It is important for conservation biologists to understand how well species
persist in human-dominated ecosystems because protected areas constitute a small
fraction of the Earth's surface and because anthropogenic habitats may offer more
opportunities for conservation than has been previously thought. We investigated how
an important functional group, pollinators (bees; Hymenoptera: Apiformes), are
affected by human land use at the landscape and local scales in southern New Jersey
(U.S.A.). We established 40 sites that differed in surrounding landscape cover or local
habitat type and collected 2551 bees of 130 species. The natural habitat in this
ecosystem is a forested, ericaceous heath. Bee abundance and species richness within
forest habitat decreased, not increased, with increasing forest cover in the
surrounding landscape. Similarly, bee abundance was greater in agricultural fields and
suburban and urban developments than in extensive forests, and the same trend was
found for species richness. Particular species groups that might be expected to show
greater sensitivity to habitat loss, such as floral specialists and bees of small or large
body size, did not show strong positive associations with forest habitat. Nevertheless,
18 of the 130 bee species studied were positively associated with extensive forest.
One of these species is a narrow endemic that was last seen in 1939. Our results
suggest that at least in this system, moderate anthropogenic land use may be
compatible with the conservation of many, but not all, bee species. [ABSTRACT
FROM AUTHOR]; DOI: 10.1111/j.1523-1739.2006.00574.x; (AN 23922664)
The importance of forest area and configuration relative to local habitat factors for
conserving forest mammals: A case study of koalas in Queensland, Australia. By:
McAlpine, Clive A.; Rhodes, Jonathan R.; Callaghan, John G.; Bowen, Michiala E.;
Lunney, Daniel; Mitchell, David L.; Pullar, David V.; Possingham, Hugh P..
Biological Conservation, Oct2006, Vol. 132 Issue 2, p153-165, 13p Abstract:
Abstract: The loss and fragmentation of forest habitats by human land use are
recognised as important factors influencing the decline of forest-dependent fauna.
Mammal species that are dependent upon forest habitats are particularly sensitive to
habitat loss and fragmentation because they have highly specific habitat
requirements, and in many cases have limited ability to move through and utilise the
land use matrix. We addressed this problem using a case study of the koala
(Phascolarctos cinereus) surveyed in a fragmented rural–urban landscape in southeast
Queensland, Australia. We applied a logistic modelling and hierarchical partitioning
analysis to determine the importance of forest area and its configuration relative to
site (local) and patch-level habitat variables. After taking into account spatial
autocorrelation and the year of survey, we found koala occurrence increased with the
area of all forest habitats, habitat patch size and the proportion of primary Eucalyptus
tree species; and decreased with mean nearest neighbour distance between forest
patches, the density of forest patches, and the density of sealed roads. The difference
between the effect of habitat area and configuration was not as strong as theory
predicts, with the configuration of remnant forest becoming increasingly important as
the area of forest habitat declines. We conclude that the area of forest, its
configuration across the landscape, as well as the land use matrix, are important
determinants of koala occurrence, and that habitat configuration should not be
overlooked in the conservation of forest-dependent mammals, such as the koala. We
highlight the implications of these findings for koala conservation.
Sacred Cows and Sympathetic Squirrels: The Importance of Biological Diversity to
Human Health. By: Dobson, Andy; Cattadori, Isabella; Holt, Robert D.; Ostfeld,
Richard S.; Keesing, Felicia; Krichbaum, Kristle; Rohr, Jason R.; Perkins, Sarah E.;
Hudson, Peter J.. PLoS Medicine, Jun2006, Vol. 3 Issue 5, pe231-0718, 5p, 3c;
Abstract: The article discusses the importance of biological diversity to human
health. A description of how disease risk is influenced by biological diversity is
presented. The role of host species in reducing the transmission of virulent zoonotic
pathogens to people is explained. Human processes that contribute to the loss of
biological diversity are cited. They include habitat loss and fragmentation, and
overexploitation of populations for food or other economic uses.; DOI: </strong>
10.1371/journal.pmed.0030231; (AN 23454842)
The roles of landscape context, niche breadth, and range boundaries in predicting
species responses to habitat alteration. By: Swihart, Robert K.; Lusk, Jeffrey J.;
Duchamp, Joseph E.; Rizkalla, Carol E.; Moore, Jeffrey E.. Diversity & Distributions,
May2006, Vol. 12 Issue 3, p277-287, 11p Abstract: Extant species in human-
dominated landscapes differ in their sensitivity to habitat loss and fragmentation,
although extinctions induced by environmental alteration reduce variation and result
in a surviving subset of species with some degree of ‘resistance’. Here, we test the
degree to which variable responses to habitat alteration are (1) essentially an inherent
property of a taxon subject to constraints imposed by its geographical range, as
suggested by Swihart et al. (2003), (2) a function of the landscape in which a species
occurs, or (3) a function of spatial trends occurring on large scales. We used data
collected on 33 vertebrate species during 2001–04 across the upper Wabash River
basin, Indiana, in 35 square ‘landscapes’, each 23 km<sup>2</sup> in size. Six
species of forest rodent, six species of grassland rodents, seven species of bats, eight
species of aquatic turtles, and six species of amphibians were sampled at 504, 212,
590, 228, and 625 patches, respectively. The fraction of patches of primary habitat
(e.g. forests for tree squirrels, wetlands for aquatic turtles) occupied by a target
species was used as a response variable. On a basin-wide scale, 47% of variation in
proportional occupancy among species could be explained by taxon-specific
variables; occupancy rates were related positively to niche breadth and negatively to
the proximity of a geographical range boundary. After controlling for species effects,
landscape-level occupancy rates varied significantly for 16 of 33 species, with
variation partitioned among landscape variables alone (mean = 11% of variation),
spatial trend variables alone (26%), and both variable sets jointly (8%). Among
landscape variables, percentage forest cover positively affected occupancy rates of
three bat species and a tree squirrel. Variation in occupancy rates among landscapes
was consistent with large-scale spatial trends for 13 species...
Confounding factors in the detection of species responses to habitat fragmentation.
By: Ewers, Robert M.; Didham, Raphael K.. Biological Reviews, Feb2006, Vol. 81
Issue 1, p117-142, 26p, 2 diagrams, 4 graphs Abstract: Habitat loss has pervasive and
disruptive impacts on biodiversity in habitat remnants. The magnitude of the
ecological impacts of habitat loss can be exacerbated by the spatial arrangement -- or
fragmentation -- of remaining habitat. Fragmentation per se is a landscape-level
phenomenon in which species that survive in habitat remnants are confronted with a
modified environment of reduced area, increased isolation and novel ecological
boundaries. The implications of this for individual organisms are many and varied,
because species with differing life history strategies are differentially affected by
habitat fragmentation. Here, we review the extensive literature on species responses
to habitat fragmentation, and detail the numerous ways in which confounding factors
have either masked the detection, or prevented the manifestation, of predicted
fragmentation effects. Large numbers of empirical studies continue to document
changes in species richness with decreasing habitat area, with positive, negative and
no relationships regularly reported. The debate surrounding such widely contrasting
results is beginning to be resolved by findings that the expected positive species-area
relationship can be masked by matrix-derived spatial subsidies of resources to
fragment-dwelling species and by the invasion of matrix-dwelling species into habitat
edges. Significant advances have been made recently in our understanding of how
species interactions are altered at habitat edges as a result of these changes.
Interestingly, changes in biotic and abiotic parameters at edges also make ecological
processes more variable than in habitat interiors. Individuals are more likely to
encounter habitat edges in fragments with convoluted shapes, leading to increased
turnover and variability in population size than in fragments that are compact in
shape. Habitat isolation in both space and time disrupts species distribution patterns,
with consequent effects on metapopulation dynamics and the...
Morphological consequences of range fragmentation and population decline on the
endangered Iberian lynx ( Lynx pardinus). By: Pertoldi, C.; García-Perea, R.; Godoy,
J. A.; Delibes, M.; Loeschcke, V.. Journal of Zoology, Jan2006, Vol. 268 Issue 1,
p73-86, 14p, 4 charts, 2 diagrams Abstract: The Iberian lynx Lynx pardinus is one of
the world's most endangered felids and is vulnerable to human-induced mortality and
habitat loss, which reduce population size and accelerate the loss of genetic variation.
Twenty-five metric traits of Iberian lynx skulls have been measured on 95 skulls
collected between 1872 and 2003. The skulls belong to three geographically distinct
areas/populations, which have recently diverged from each other as a consequence of
increased habitat fragmentation: Doñana area, Sierra Morena mountains and Montes
de Toledo area. The morphometric study was undertaken using univariate,
multivariate and admixture analysis approaches, and all three techniques provided
evidence for morphometric differentiation, both in skull size and shape, among the
three populations for both males and females. Environmental and genetic forces that
may have shaped these patterns are discussed. The males of the population of the
Doñana area showed a different degree of reduction in size in nine of the skull traits
with time, which has been suggested to be partly because of worsened habitat
conditions. However, the heterogeneity of the degree of mean size reduction and the
relatively high degree of reduction of some of the skull traits investigated (>4%),
which have altered the original proportions between the skull variables, could also
partly be attributed to inbreeding depression in the Doñana population. The
phenotypic variability of the skull traits showed significant increases (two traits) or
decreases (nine traits) with time, and this different pattern of change with time has
been suggested to be because of a different number of genes controlling the traits with
different degrees of dominance and epistatic interactions. The increased phenotypic
variability of two of the traits has also been attributed to a possible decreased level of
developmental stability, which can be produced by environmental and/or genetic
stress. The findings of... [ABSTRACT FROM AUTHOR]; DOI: 10.1111/j.14697998.2005.00024.x; (AN 20753736)
Not seeing the ocean for the islands: the mediating influence of matrix-based
processes on forest fragmentation effects. By: Kupfer, John A.; Malanson, George P.;
Franklin, Scott B.. Global Ecology & Biogeography, Jan2006, Vol. 15 Issue 1, p8-20,
13p, 1 diagram, 6bw Abstract: The pervasive influence of island biogeography theory
on forest fragmentation research has often led to a misleading conceptualization of
landscapes as areas of forest/habitat and ‘non-forest/non-habitat’ and an overriding
focus on processes within forest remnants at the expense of research in the humanmodified matrix. The matrix, however, may be neither uniformly unsuitable as habitat
nor serve as a fully–absorbing barrier to the dispersal of forest taxa. In this paper, we
present a conceptual model that addresses how forest habitat loss and fragmentation
affect biodiversity through reduction of the resource base, subdivision of populations,
alterations of species interactions and disturbance regimes, modifications of
microclimate and increases in the presence of invasive species and human pressures
on remnants. While we acknowledge the importance of changes associated with the
forest remnants themselves (e.g. decreased forest area and increased isolation of forest
patches), we stress that the extent, intensity and permanence of alterations to the
matrix will have an overriding influence on area and isolation effects and emphasize
the potential roles of the matrix as not only a barrier but also as habitat, source and
conduit. Our intention is to argue for shifting the examination of forest fragmentation
effects away from a patch-based perspective focused on factors such as patch area and
distance metrics to a landscape mosaic perspective that recognizes the importance of
gradients in habitat conditions. [ABSTRACT FROM AUTHOR]; DOI:
10.1111/j.1466-822X.2006.00204.x; (AN 19328965)
Mammal Conservation in Brazil. By: COSTA, LEONORA PIRES; LEITE, YURI
LUIZ REIS; MENDES, SÉRGIO LUCENA; DITCHFIELD, ALBERT DAVID.
Conservation Biology, Jun2005, Vol. 19 Issue 3, p672-679, 8p Abstract (English):
Brazil is the fifth largest country in the world and the first of the megadiversity
countries, accounting for roughly 14% of the world's biota. It has the largest mammal
diversity (more than 530 described species) with many yet to be discovered and
cataloged. Very few sites have been adequately surveyed, and local lists are usually
incomplete, which makes for knowledge gaps that hamper conservation and
management initiatives and regional analyses. According to the Brazilian Institute for
the Environment (IBAMA), 66 species are threatened, and the World Conservation
Union lists 74. Primates, mostly Atlantic Forest endemics, are the most endangered
group (40% of the threatened taxa). Carnivores and rodents are also notable members
of the lists. Twenty-nine percent of listed species are marine, 18% occur in the
Atlantic Forest, 13% in the Pampas, 12% in the Cerrado, 11% in the Pantanal, 7% in
the Amazon, and 6% in the Caatinga. Human-induced habitat loss and
fragmentation are major threats to land mammals in Brazil, and large- and mediumsized mammals are hunted. The major threat to small mammals is the scarcity of basic
scientific knowledge—taxonomy, systematics, distribution, and natural history.
Aquatic mammals are threatened by commercial hunting, accidental netting, long-line
fisheries, chemical pollution, habitat degradation, tourism, and boat traffic. Mammal
conservation has benefited from a number of recent initiatives by government and
nongovernmental organizations, including legislation, nationwide initiatives to define
priority areas for conservation, management plans for some threatened species,
sustainable landscape planning, and new protected areas. Given the rate of habitat
loss, a nationwide program of short- and long-term field surveys and increased
support for natural history collections is of particularly urgency. Progress has been
made toward conserving Brazilian mammals in recent years, but threats are growing
fast, and conservation... [ABSTRACT FROM AUTHOR]; DOI: 10.1111/j.15231739.2005.00666.x; (AN 17204920)
Responses of ‘resistant’ vertebrates to habitat loss and fragmentation: the importance
of niche breadth and range boundaries. By: Swihart, Robert K.; Gehring, Thomas M.;
Kolozsvary, Mary Beth; Nupp, Thomas E.. Diversity & Distributions, Jan2003, Vol. 9
Issue 1, p1-18, 18p Abstract: Abstract. An ability to predict species’ sensitivities to
habitat loss and fragmentation has important conservation implications, and
numerous hypotheses have been proposed to explain interspecific differences
observed in human-dominated landscapes. We used occupancy data collected on 32
species of vertebrates (16 mammals and 16 amphibians) in an agricultural landscape
of Indiana, USA, to compare hypotheses that focus on different causal mechanisms
underlying interspecific variation in responses to habitat alteration: (1) body size; (2)
morphology and development; (3) behaviour; (4) niche breadth; (5) proximity to
range boundary; and multiple-process models combining main effects and interactions
of hypotheses (1)–(2) and (4)–(5). The majority of habitat alteration occurred over a
century ago and coincided with extinction of several species; thus, our study dealt
only with variation in responses of extant species that often are considered ‘resistant’
to human modifications of native habitat. Corrected Akaike scores and Akaike
weights provided strongest support for models incorporating niche breadth and
proximity to range boundary. Measures of dietary and habitat breadth obtained from
the literature were negatively correlated with sensitivity to habitat alteration.
Additionally, greater sensitivity was observed for species occurring at the periphery of
their geographical ranges, especially at northern or western margins. Body size,
morphological, developmental and behavioural traits were inferior predictors of
tolerance to fragmentation for the species and landscape we examined. Our findings
reinforce the importance of niche breadth as a predictor of species’ responses to
habitat alteration. They also highlight the importance of viewing the effects of habitat
loss and fragmentation in a landscape within a biogeographical context that considers
a species’ level of adaptation to local environmental conditions. [ABSTRACT FROM
AUTHOR]; DOI: 10.1046/j.1472
Extinction Debt at Extinction Threshold. By: Hanski, Ilkka; Ovaskainen, Otso.
Conservation Biology, Jun2002, Vol. 16 Issue 3, p666-673, 8p Abstract: To allow for
long-term metapopulation persistence, a network of habitat fragments must satisfy a
certain condition in terms of number, size, and spatial configuration of the fragments.
The influence of landscape structure on the threshold condition can be measured by a
quantity called metapopulation capacity, which can be calculated for real fragmented
landscapes. Habitat loss and fragmentation reduce the metapopulation capacity of a
landscape and make it less likely that the threshold condition can be met. If the
condition is not met, the metapopulation is expected to go extinct, but it takes some
time following habitat loss before the extinction will occur, which generates an
extinction debt in a community of species. We show that extinction debt is especially
great in a community in which many species are close to their extinction threshold
following habitat loss because the metapopulation-dynamic time delay is especially
long in such species. A corollary is that landscapes that have recently experienced
substantial habitat loss and fragmentation are expected to show a transient excess of
rare species, which represents a previously overlooked signature of extinction debt.
We consider a putative example of extinction debt on forest-inhabiting beetles in
Finland. At present, the few remaining natural-like forests are distributed evenly
throughout southern Finland, but the number of regionally extinct old-growth forest
beetles is much greater in the southwestern coastal areas, where human impact on
forests has been lengthy, than in the northeastern inland areas, where intensive
forestry started only after World War II. Ignoring time delays in population and
metapopulation dynamics will lead to an underestimate of the number of effectively
endangered species. [ABSTRACT FROM AUTHOR]; DOI: 10.1046/j.15231739.2002.00342.x; (AN 6804085)
Quantifying barrier effects of roads and seismic lines on movements of female
woodland caribou in northeastern Alberta. By: O'Neill, Jack P.; Boutin, Stan.
Canadian Journal of Zoology, May2002, Vol. 80 Issue 5, p839, 7p; Abstract: Linear
developments such as roads, seismic lines, and pipeline rights-of-way are common
anthropogenic features in the boreal forest of Alberta. These features may act as
barriers to the movement of threatened woodland caribou, Rangifer tarandus caribou.
Seismic lines were not barriers to caribou movements, whereas roads with moderate
vehicle traffic acted as semipermeable barriers to caribou movements. Twenty-two
adult female and 1 adult male woodland caribou were captured and collared on
February 17–19, 1998. Each caribou was fitted with a global positioning system
collar. The greatest barrier effects were evident during late winter, when caribou
crossed actual roads 6 times less frequently than simulated road networks.
Semipermeable barrier effects may exacerbate functional habitat loss demonstrated
through avoidance behavior. Caribou may cross roads less frequently than expected
for a number of reasons, including an aversion to the physical barrier presented by a
road and associated forest opening, vehicle traffic, or predation by humans. The
effects of habitat fragmentation through habitat loss, avoidance, and the
semipermeable barrier effects of roads should be considered in developing strategies
to maintain woodland caribou populations in Alberta. Roads that act as
semipermeable barriers to caribou movements may make the presence of caribou
more predictable in space and time, and hence compromise the "spacing out" strategy
that caribou adopt to reduce predation. The approach we have outlined in this paper is
a useful method to quantify the effects of human developments acting as
semipermeable barriers to animal movements and should be considered in the
development of animal-movement models.; (AN 10250737)
Characteristics of insect populations on habitat fragments: A mini review. By:
Tscharntke, Teja; Steffan-Dewenter, Ingolf; Kruess, Andreas; Thies, Carsten.
Ecological Research, Mar2002, Vol. 17 Issue 2, p229-239, 11p Abstract: Modern
human-dominated landscapes are typically characterized by intensive land-use and
high levels of habitat destruction, often resulting in sharply contrasted habitat
mosaics. Fragmentation of remaining habitat is a major threat to biodiversity. In the
present paper, we focus on the different features of habitat fragmentation. First we
discuss the importance of pure habitat loss, fragment size, fragment isolation and
quality, edge effects, and the importance of landscape structure. Second, we
characterize life-history features of fragmentation-sensitive species, showing that
rare, specialized, little dispersing species are most affected, as well as species
characterized by high population variability and a high trophic position, while the
effect of body size is unclear. Third, we discuss the conservation value of habitat
fragments. The question arises how to relate studies on population survival to those of
community structure and studies on biodiversity to those on ecologicalal functions.
Despite the general superiority of large to small reserves, only small or medium-sized
reserves are available in many human-dominated landscapes. A great number of
small habitats covering a wide range of geographic area should maximize beta
diversity and spreading of risk and may be very important for the regional
conservation of biodiversity, in contrast to the prevailing arguments in favor of large
habitats. Finally, landscape context influences community structure of fragments, and
communities are composed of species that experience the landscape on a broad range
of spatial scales. Spatial arrangement of habitat fragments in a landscape appears to
be important only in simple, not complex landscapes. [ABSTRACT FROM
AUTHOR]; DOI: 10.1046/j.1440-1703.2002.00482.x; (AN 6571717)
Habitat loss, fragmentation and predator impact: spatial implications for prey
conservation. By: Schneider, Michael F.. Journal of Applied Ecology, Aug2001, Vol.
38 Issue 4, p720-735, 16p, 4 charts, 2 diagrams, 9 graphs Abstract: Summary
1.Because predators threaten the survival of endangered prey in many places, predator
management is a widespread conservation tool. At the same time, the effects of
predators on their prey are greatly influenced by landscape structure. Therefore, the
management of landscapes could be an alternative to predator regulation. 2.A
spatially explicit presence/absence model (a stochastic one-layer cellular automaton)
was used to investigate two different predator–prey systems that were subject to
changes in the number and size of habitat patches in a model landscape. 3.The first
scenario included grey-sided voles Clethrionomys rufocanus , Norwegian lemmings
Lemmus lemmus and small mustelids (stoats Mustela erminea and weasels M. nivalis
) interacting in a tundra landscape. In the second scenario, the effect of habitat
perforation by human settlements with subsidized predators (house cats Felis
silvestris catus ) on the dynamics of lemmings (as surrogate for endangered prey) was
studied. 4.Both the total area of lemming habitat and the degree of fragmentation
were important determinants of the population size and persistence of lemmings. A
qualitative change in the effect of fragmentation was observed when the area of
lemming habitat decreased from 70% (positive effect) to 50% (negative effect). When
lemming habitat covered 50% or less of the landscape, fragmentation had a negative
effect on lemming population size and viability, even though habitat area did not
decrease. 5.The spatial configuration of settlements as predator sources was
important. A few evenly spaced predator sources had less negative effect on lemming
populations than the same proportion of predator habitat that was randomly
distributed, which in turn had less effect than many evenly spaced patches.
6.Including predator management in the model did not decrease the predators’
negative impact on the population size and persistence of the endangered prey when
settlements occurred in... [ABSTRACT FROM AUTHOR]; DOI: 10.1046/j.1365
Phylogeography, population history and conservation genetics of jaguars (Panthera
onca , Mammalia, Felidae). By: Eizirik, Eduardo; Kim, Jae-Heup; Menotti-Raymond,
Marilyn; Crawshaw JR., Peter G.; O’Brien, Stephen J.; Johnson, Warren E..
Molecular Ecology, Jan2001, Vol. 10 Issue 1, p65-79, 15p, 5 charts, 3 diagrams, 3
graphs, 1 map Abstract: Abstract The jaguar (Panthera onca ), the largest felid in the
American Continent, is currently threatened by habitat loss, fragmentation and
human persecution. We have investigated the genetic diversity, population structure
and demographic history of jaguars across their geographical range by analysing 715
base pairs of the mitochondrial DNA (mtDNA) control region and 29 microsatellite
loci in ≈40 individuals sampled from Mexico to southern Brazil. Jaguars display low
to moderate levels of mtDNA diversity and medium to high levels of microsatellite
size variation, and show evidence of a recent demographic expansion. We estimate
that extant jaguar mtDNA lineages arose 280 000–510 000 years ago (95% CI 137
000–830 000 years ago), a younger date than suggested by available fossil data. No
strong geographical structure was observed, in contrast to previously proposed
subspecific partitions. However, major geographical barriers such as the Amazon
river and the Darien straits between northern South America and Central America
appear to have restricted historical gene flow in this species, producing measurable
genetic differentiation. Jaguars could be divided into four incompletely isolated
phylogeographic groups, and further sampling may reveal a finer pattern of
subdivision or isolation by distance on a regional level. Operational conservation units
for this species can be defined on a biome or ecosystem scale, but should take into
account the historical barriers to dispersal identified here. Conservation strategies for
jaguars should aim to maintain high levels of gene flow over broad geographical
areas, possibly through active management of disconnected populations on a regional
scale. [ABSTRACT FROM AUTHOR]; DOI: 10.1046/j.1365-294X.2001.01144.x;
(AN 5514493)
Human and domestic animal populations as a potential threat to wild carnivore
conservation in a fragmented landscape from the Eastern Brazilian Amazon
Biological Conservation, Volume 138, Issues 1-2, August 2007, Pages 290-296
Christina Wippich Whiteman, Eliana Reiko Matushima, Ulisses Eugênio Cavalcanti
Confalonieri, Maria das Dores Correia Palha, Alanna do Socorro Lima da Silva and
Vanessa Conceição Monteiro
SummaryPlus
Hydroelectric projects are one of the well known factors responsible for habitat loss
and fragmentation in the Amazon. The Tucuruí Lake Protected Area (Tucuruí Lake
APA), in the state of Pará, Brazil, Eastern Brazilian Amazon, is under the influence of
the Tucuruí dam. Zones of wildlife protection (ZWPs), where no human activities
should be allowed, were created inside this protected area. However, human
populations and their domestic animals still reside within the ZWPs. Domestic
carnivores have been implicated in wild carnivore population declines, particularly in
Africa, as a consequence of disease transmission, especially involving the canine
distemper virus. This study examined the seroprevalence of antibodies to this
pathogen in domestic dogs from the ZWPs and its immediate surroundings at the
Tucuruí Lake Protected Area, and revealed 27% seropositivity. Wild carnivore
species such as the jaguar (Panthera onca), puma (Puma concolor), ocelot (Leopardus
pardalis), coati (Nasua nasua), among others, inhabit the ZWPs and information
provided by the local community indicates their close contact with the human and
domestic dog populations. Such evidence supports the concern that relates the
presence of the domestic dogs to disease transmission and conservation risks for wild
carnivores in the ZWPs of the Tucuruí Lake APA.
Village size and forest disturbance in Bhadra Wildlife Sanctuary, Western Ghats,
India
Biological Conservation, Volume 128, Issue 2, March 2006, Pages 147-157
Krithi K. Karanth, Lisa M. Curran and Jonathan D. Reuning-Scherer
SummaryPlus
Habitat fragmentation, land cover change and biodiversity loss are often associated
with village communities in protected areas, but the extent and intensity of such
impacts are often inadequately assessed. We record resource use and depletion by
human inhabitants by conducting ecological surveys in six villages and social surveys
in all 13 villages of varying sizes in India’s Bhadra Wildlife Sanctuary (492 km2). We
examined the occurrence of 10 regionally-specific ecological indicators that
encompassed several aspects of human activities. Thirty transects with 180 total
sampling locations recorded the occurrence of these specific habitat disturbance
variables. High correlations between the variables led to the use of principal
component analysis to derive an effective summary index that reflected disturbance
intensity and determined village ecological impacts spatially. A generalized linear
model was fit to determine the rate at which disturbance decreases as we move away
from village centers. Our model indicates that village size class, distance from the
village and proximity to other villages were significant predictors of the disturbance
index. The index distinguished each village’s spatially explicit ecological impact. We
estimated that an average area of 23.7 km2 of the forest surrounding the six focal
villages was altered by human activities. These six villages have directly impacted 8–
10% of this protected area.
Influence of former cultivation on the unique Mediterranean steppe of France and
consequences for conservation management
Biological Conservation, Volume 121, Issue 1, January 2005, Pages 21-33
Christine Römermann, Thierry Dutoit, Peter Poschlod and Elise Buisson
SummaryPlus
In Europe, the actual landscape has been mainly influenced by human activities.
Agricultural intensification led to a considerable habitat loss and fragmentation,
especially for dry semi-natural grasslands.
This current study investigates the impact of former melon and cereal cultivation
(cultivation period: 1950–1987) on the semi-natural vegetation of the Crau,
representing the last xeric Mediterranean steppe in France.
Today, the ex-cultivated melon and cereal fields are characterised by different
vegetation compositions, species richness and evenness compared to the undisturbed
steppe community. Also the abiotic conditions (N, P, K, pH, soil granule fractions)
have been changed by former cultivation practices. The rather transient seed bank of
the steppe was depleted during the cultivation periods; ancient weed species and
ruderals now determine the seed bank of the ex-cultivated fields.
It is concluded that the conservation of the last parts of undisturbed steppe must have
absolute priority. A re-development of the original and unique steppe community on
formerly cultivated fields may take decades or centuries, if at all.
The impact of free-roaming dogs on gazelle kid/female ratio in a fragmented area
Biological Conservation, Volume 119, Issue 2, September 2004, Pages 231-236
Regev Manor and David Saltz
SummaryPlus
One of the consequences of fragmentation is a combination of increased proximity to
human dominated areas and an influx of free-roaming dogs. In fragmented habitats
those dogs are expected to have a considerable impact on ungulate populations since
conditions are, in effect, similar to alien species on islands. We studied the impact of
free-roaming dogs (Canis familiaris) on the kid/mother ratio of mountain gazelle
(Gazella gazella gazella) in an isolated area heavily disturbed by human activity. We
used the kid/female ratio as an index of recruitment in the gazelle populations and
evaluated the impacts of dog presence, intensity of human disturbance, and forage and
cover availability on this ratio over space and time. Data were collected from direct
observations. Overall, kid/female ratio in the area is too low for population growth; a
finding that is in agreement with drive counts indicating a consistent decline over the
past four years (1998–2001). Our results show that free-roaming dogs were the
overwhelming factor affecting kid/female ratio in this area. Gazelles responded
positively and quickly to dog culling. Thus, free-roaming dogs appear to be a
considerable threat to the gazelle population in the study area. Removal of those dogs
on a regular basis is an adequate short-term management protocol for increasing
gazelle recruitment rate. However, a permanent solution would require reducing the
number of dogs by limiting human waste disposal. These results suggest that, in
addition to the loss of habitat and connectivity, free-roaming dogs can be a major
threat to native ungulates in human dominated fragmented landscapes.
Spatial arrangement of habitat patches and corridors: clues from ecological field
experiments
Landscape and Urban Planning, Volume 42, Issues 2-4, 7 December 1998, Pages 157168
Sharon K. Collinge
SummaryPlus
Habitat loss and isolation associated with land conversion for human activities pose
perhaps the most severe threat to the earth's biological diversity. Because the study of
habitat fragmentation provides an important link between the concepts of landscape
ecology and the practice of landscape architecture and planning, my dissertation
research focused on the ecological consequences of changes in the spatial
characteristics of native habitats. I completed two major field experiments with
insects in a native grassland near Boulder, Colorado, USA, that directly tested
ecological hypotheses regarding the influences of habitat spatial characteristics and
patterns of land conversion on species loss, recolonization, and movement patterns.
The first experiment focused on fragment size and connectivity, while the second
experiment mimicked four sequences of land conversion that varied in size,
connectivity and spatial arrangement of their remnant habitat patches. Both
experiments yielded significant results that contribute to the ecological knowledgebase utilized in landscape architecture and planning projects. Specifically, the major
findings of my field research were (1) fragment size influenced species loss; small
fragments lost species at a higher rate than did larger fragments; (2) corridors reduced
rates of species loss, but only in medium-sized fragments; (3) corridors enhanced
recolonization of medium-sized fragments, (4) one of the three insect species
examined moved preferentially in corridors; and (5) spatial configuration of land
conversion sequences significantly influenced species richness.
Cumulative environmental impacts and aboriginal rights
Environmental Impact Assessment Review, Volume 18, Issue 4, July 1998, Pages
371-390
C. Tollefson and K. Wipond
SummaryPlus
Over the past two decades, increasing attention has been devoted to the concept of
cumulative environmental effects. Cumulative effects are the additive and interactive
impacts that may result from human activities that are repeated over time and space.
In many cases, numerous small, independent actions considered to be individually
insignificant can eventually lead to substantial and sometimes irreversible changes in
the environment. Public awareness of such impacts is often minimal, until such time
as a critical point or threshold is exceeded. By this time the environmental and social
consequences may be considerable. Habitat loss and fragmentation, climate
modification, soil loss, declines in water quantity and quality, and pesticide
accumulation are just a few of the areas in which cumulative effects have become a
major concern. Recently proclaimed Canadian environmental assessment laws impose
new requirements to identify and address cumulative effects. So far, however,
considerable uncertainty exists as to how these statutory requirements will or should
be carried out. This uncertainty is compounded by the constitutional requirement to
recognize and protect various traditional aboriginal rights. The Canadian Constitution
recently has been interpreted to protect the right of aboriginal people to engage in
traditional sustenance-oriented hunting, fishing, trapping, and gathering activities.
Moreover, following a landmark decision of the Supreme Court of Canada in late
1997, aboriginal people are now entitled to assert rights of exclusive use and
occupation to land under the emerging legal concept of aboriginal title. The struggle
by aboriginal peoples for legal recognition of these rights has been long and difficult.
A growing number of aboriginal communities have voiced concerns that these newly
recognized rights are being threatened by the cumulative environmental effects of
resource development and human settlement. Paradoxically, just as the quest for
traditional rights recognition is coming to fruition, the ability of aboriginal peoples to
exercise these rights appears to be eroding. The purpose of this article is to examine
how the concept of cumulative effects, together with the legal imperative to protect
traditional aboriginal rights, can and must transform environmental decision-making.
It is in four parts. Part I explores the meaning and policy implications of the concept
of cumulative environmental impacts. Part II is an introduction to the legal and
historical basis for aboriginal rights. Part III seeks to illustrate the challenges, and the
necessity, of reforming environmental decision-making by use of a case-study
involving a controversy over logging in traditional aboriginal territory. In Part IV we
offer some concluding observations in the implications of our analysis for
environmental assessment and decision-making.
TI:
Modeling human factors that affect the loss of biodiversity.
AU:
Forester,-D-J; Machlis,-G-E
AD:
Department of Forest Resources, University of Idaho, Moscow,
ID 83844, USA.
SO:
Conservation-Biology. 1996; 10(4): 1253-1263
RE:
76 ref.
PY:
1996
LA:
English
LS:
Spanish
AB:
The paper describes the development and testing of an
interdisciplinary model incorporating human factors that affect
biodiversity loss and demonstrates the possibilities and difficulties
associated with modeling biodiversity loss. The model has been
developed and tested using socioeconomic and ecological data from 107
countries. Variables in the model include: social, economic and
political forces (human population, monetary wealth and capital,
government policies); human use of resources (natural resource
production activities, land cover, industrial activity); ecosystem
impacts (habitat loss and fragmentation, ecosystem stress, natural
forces); and biodiversity loss. Some portions of the model fit the
data well while other parts are less predictive. Counterintuitive
results may be a result of the quality and availability of crossnational data and statistical limitations in testing a model of such
complex processes. The model test provides insight into future
research needs for examining human impacts on biodiversity. Issues
discussed include data quality and temporal and spatial scale.
DE:
human-behaviour; biodiversity-; modelsCC:
PP700; EE150; EE120
CD:
Biological-Resources-General; Environmental-Economics; Policyand-Planning
PT:
Journal-article
IS:
0888-8892
UD:
199600
AN:
19961809131
TI:
Factors affecting the persistence of New England cottontail
metapopulations: the role of habitat management.
AU:
Litvaitis,-J-A; Villafuerte,-R
AD:
Wildlife Program, Department of Natural Resources, Pettee
Hall, University of New Hampshire, Durham, NH 03824, USA.
SO:
Wildlife-Society-Bulletin. 1996; 24(4): 686-693
RE:
48 ref.
PY:
1996
LA:
English
AB:
The distribution and abundance of New England cottontails
(Sylvilagus transitionalis) have declined dramatically in response to
land-use changes and expanding human populations. Computer
simulations in the context of metapopulation theory was used to
understand the effects of environmental correlation, habitat loss and
habitat management on remaining populations of the rabbit.
Environmental correlation (based on increased vulnerability to
predation during periods with snow) and habitat loss (based largely
on forest maturation) can each affect the persistence of
metapopulations. The synergistic effect of these 2 variables can
cause a rapid decline in rabbit populations or local extinctions. A
management programme that maintains a network of suitable habitats
can counter the negative effects. Patches (15-75 ha) of early
successional habitat that are maintained with a regime of periodic
disturbances (burning, cutting or mowing) may be sufficient to
sustain local populations of New England cottontails.
DE:
fragmentation-; landscape-; simulation-; persistence-;
management-; populations-; wildlife-management; computer-simulation;
wildlifeOD:
sylvilagus-; rabbitsGE:
New-england-states-of-usa; USAID:
Sylvilagus-transitionalis
BT:
Leporidae-; Lagomorpha-; mammals-; vertebrates-; Chordata-;
animals-; small-mammals; Northeastern-States-of-USA; USA-; NorthAmerica; America-; Developed-Countries; OECD-Countries
CC:
KK100; PP710
CD:
Forests-and-Forest-Trees-Biology-and-Ecology; BiologicalResources-Animal
PT:
Journal-article
IS:
0091-7648
UD:
199700
AN:
19970608159
SM:
OZ
TI:
Three views (and four glimpses) of a secret: challenges in
epidemiology.
AU:
Dobson,-A; Hudson,-P-J
ED:
Thomas,-M-B; Kedwards,-T
AD:
Ecology and Evolutionary Biology, Eno Hall, Princeton
University, Princeton, NJ 08544-1003, USA.
SO:
Aspects-of-Applied-Biology. 1999; (53): 17-26
CF:
Challenges in applied population biology, Royal Holloway,
University of London, UK, 8-9 July 1999.
RE:
49 ref.
PY:
1999
LA:
English
AB:
Parasites and pathogens present a range of challenging
problems for applied biologists. In this brief review three major
problems in this area are examined: (1) the impact of climate change
on seasonality, (2) parasites as biological control agents for
invasive species and (3) pathogens and human health. The reader is
also directed to four other problem areas: (4) the evolution of drug
and insecticide resistance, (5) habitat loss, fragmentation and
pathogens, (6) the role of pathogens in maintaining diversity, and
(7) the interactions between malnutrition, stress, immunity and
parasite infection. Ecological epidemiology is steadily expanding
from its refuge as an arcane area of applied mathematics. The last
fifteen years have seen a renaissance of ecological studies that
address a range of applied problems for pathogens that directly
impact humans, livestock and natural and threatened ecological
communities. Unfortunately, it is still true that while infectious
diseases will create some of the major biological challenges of the
next century, too few biologists are trained in the 'secret' delights
of parasitism. The central theme underlying this paper is to tempt
others to join us.
DE:
epidemiology-; biological-control; biological-control-agents;
communities-; diversity-; evolution-; immunity-; infectious-diseases;
insecticide-resistance; interactions-; livestock-; malnutrition-;
parasites-; habitats-; pathogens-; stress-; environment-; ecosystems; invasion-; helminthsOD:
man-; protozoaBT:
Homo-; Hominidae-; Primates-; mammals-; vertebrates-;
Chordata-; animals-; invertebratesCC:
HH100; HH600; HH410; LL820; PP500
CD:
Biological-Control; Host-Resistance-and-Immunity; Pesticideand-Drug-Resistance; Parasites-Vectors-Pathogens-and-BiogenicDiseases-of-Animals; Meteorology-and-Climate
PT:
Conference-paper; Journal-article
IS:
0265-1491
UD:
199900
AN:
19990806802
TI:
Conservation of the Cape parrot in southern Africa.
AU:
Wirminghaus,-J-O; Downs,-C-T; Symes,-C-T; Perrin,-M-R
AD:
School of Botany & Zoology, University of Natal, Private Bag
X01, Scottsville, Pietermaritzburg, 3209, South Africa.
SO:
South-African-Journal-of-Wildlife-Research. 1999; 29(4): 118129
RE:
77 ref.
PY:
1999
LA:
English
AB:
Features of its breeding and feeding biology make the Cape
parrot (Poicephalus robustus) demographically vulnerable. The species
occurs in the fragmented Afromontane forest in the Eastern Cape and
KwaZulu-Natal, South Africa. Population numbers have declined
significantly in recent years. Possible factors contributing to this
decline include habitat loss, food shortage, the low reproductive
rate, human predation and disease. Selective felling of Podocarpus
spp., the preferred food tree and nest site species, has caused food
shortage and nest site scarcity. Recommendations for the conservation
of Cape parrots are presented.
DE:
feeding-behaviour; felling-; tropical-forests; selectivefelling; wild-birds; wildlife-conservation; forest-fragmentation;
habitats-; nesting-; forest-ecology
OD:
parrots-; Podocarpus-; PsittacidaeGE:
South-Africa
ID:
Poicephalus-; Poicephalus-robustus
BT:
Psittacidae-; Psittaciformes-; birds-; vertebrates-; Chordata; animals-; Podocarpaceae-; Pinopsida-; gymnosperms-; Spermatophyta-;
plants-; Southern-Africa; Africa-South-of-Sahara; Africa-;
Developing-Countries; Threshold-Countries; Anglophone-Africa;
Commonwealth-of-Nations
CC:
KK100; PP710; ZZ331; PP600; ZZ332; YY500
CD:
Forests-and-Forest-Trees-Biology-and-Ecology; BiologicalResources-Animal; Plant-Ecology; Pollution-and-Degradation; AnimalEcology; Behaviour-Wild-Animals
PT:
Journal-article
IS:
0379-4369
UD:
200000
AN:
20000611324
SM:
OPS\Repr/6373
*LHM: Main Library,Main Library
TI:
Ecological degradation in protected areas: the case of Wolong
Nature Reserve for giant pandas.
AU:
Liu-JianGuo; Linderman,-M; Ouyang-ZhiYun; An-Li; Yang-JiAn;
Zhang-HeMin
AD:
Department of Fisheries and Wildlife, 13 Natural Resources
Building, Michigan State University, East Lansing, MI 48824, USA.
SO:
Science-Washington. 2001; 292(5514): 98-101
PB:
Washington, USA: American Association for the Advancement of
Science.
RE:
29 ref.
PY:
2001
LA:
English
AB:
It is generally perceived that biodiversity is better
protected from human activities after an area is designated as a
protected area. However, we found that this common perception was not
true in Wolong Nature Reserve, Sichuan Province, southwestern China,
which was established in 1975 as a 'flagship' protected area for
giant pandas (Ailuropoda melanoleuca). Analyses of remote sensing
data from pre- and post-establishment periods indicate that forest in
the reserve has become more fragmented and less suitable for giant
panda habitation. The rate of loss of high-quality habitat after the
reserve's establishment was much higher than before the reserve was
created, and the fragmentation of high-quality habitat became far
more severe. After the creation of the reserve, rates of habitat loss
and fragmentation inside the reserve unexpectedly increased to levels
that were similar to or higher than those outside the reserve, in
contrast to the situation before the reserve was created.
DE:
biodiversity-; endangered-species; forest-fragmentation;
habitat-destruction; habitats-; human-activity; nature-conservation;
nature-reserves
OD:
Ailuropoda-melanoleuca
GE:
China-; Sichuan-
BT:
Ailuropoda-; Ailuropodidae-; Fissipeda-; carnivores-; mammals; vertebrates-; Chordata-; animals-; East-Asia; Asia-; DevelopingCountries; South-Western-China; ChinaCC:
PP710; ZZ332; KK100; PP600
CD:
Biological-Resources-Animal; Animal-Ecology; Forests-andForest-Trees-Biology-and-Ecology; Pollution-and-Degradation
PT:
Journal-article
IS:
0036-8075
UD:
200100
AN:
20013053512
SM:
OPS\P
*LHM: Frik-Scott Library,Main Library
TI:
Factors affecting bird communities in fragments of secondary
pine forests in the north-western Mediterranean basin.
AU:
Brotons,-L; Herrando,-S
AD:
Dept. Biologia Animal (Vertebrats), Universitat de Barcelona,
Av. Diagonal 645, 08028 Barcelona, Spain.
SO:
Acta-Oecologica. 2001; 22(1): 21-31
PB:
Paris, France: Editions Scientifiques et Medicales Elsevier
SAS.
RE:
37 ref.
PY:
2001
LA:
English
AB:
We assessed the influence of size, extent of isolation and
vegetation structure of secondary forest fragments on the richness
and species composition of breeding bird communities in a sample of
pine (Pinus halepensis) forest fragments surrounded by an
agricultural matrix in the north-western Mediterranean basin (the
Penedes area of NE Spain). Fragment size was the main predictor of
bird's occurrence, since it accounted for 70% of the model variation.
Isolation was also a valuable predictor of species occurrence,
especially for forest specialists. Finally, subarboreal vegetation
such as holm oak (Quercus ilex) and a well-developed tree layer of
large pines favoured forest species occurrence. Therefore, in spite
of the long history of human impact, forest birds in Mediterranean
mosaics are sensitive to both habitat loss and isolation of remnant
patches in a similar manner to the patterns found in other temperate
fragmented landscapes where human impact is more recent.
DE:
forest-fragmentation; forests-; habitats-; wild-birds
OD:
birds-; Pinus-halepensis; Quercus-ilex
GE:
SpainBT:
vertebrates-; Chordata-; animals-; Southern-Europe; Europe-;
Mediterranean-Region; Developed-Countries; European-Union-Countries;
OECD-Countries; Pinus-; Pinaceae-; Pinopsida-; gymnosperms-;
Spermatophyta-; plants-; Quercus-; Fagaceae-; Fagales-; dicotyledons; angiospermsCC:
KK100; ZZ332; PP710
CD:
Forests-and-Forest-Trees-Biology-and-Ecology; Animal-Ecology;
Biological-Resources-Animal
PT:
Journal-article
IS:
1146-609X
UD:
200100
AN:
20013035444
SM:
OPS\P
TI:
Habitat loss, fragmentation and predator impact: spatial
implications for prey conservation.
AU:
Schneider,-M-F
AD:
Department of Ecology and Environmental Science, Umea
University, SE-901 87 Umea, Sweden.
SO:
Journal-of-Applied-Ecology. 2001; 38(4): 720-735
PB:
Oxford, UK: Blackwell Science.
RE:
83 ref.
PY:
2001
LA:
English
AB:
Because predators threaten the survival of endangered prey in
many places, predator management is a widespread conservation tool.
At the same time, the effects of predators on their prey are greatly
influenced by landscape structure. Therefore, the management of
landscapes could be an alternative to predator regulation. A
spatially explicit presence/absence model (a stochastic one-layer
cellular automaton) was used to investigate 2 different predator-prey
systems that were subject to changes in the number and size of
habitat patches in a model landscape. The 1st scenario included greysided voles Clethrionomys rufocanus, Norwegian lemmings Lemmus lemmus
and small mustelids (stoats, Mustela erminea and weasels, M. nivalis)
interacting in a tundra landscape. In the 2nd scenario, the effect of
habitat perforation by human settlements with subsidized predators
(house cats, Felis silvestris catus) on the dynamics of lemmings (as
surrogate for endangered prey) was studied. Both the total area of
lemming habitat and the degree of fragmentation were important
determinants of the population size and persistence of lemmings. A
qualitative change in the effect of fragmentation was observed when
the area of lemming habitat decreased from 70% (positive effect) to
50% (negative effect). When lemming habitat covered 50% or less of
the landscape, fragmentation had a negative effect on lemming
population size and viability, even though habitat area did not
decrease. The spatial configuration of settlements as predator
sources was important. A few evenly spaced predator sources had less
negative effect on lemming populations than the same proportion of
predator habitat that was randomly distributed, which in turn had
less effect than many evenly spaced patches. Including predator
management in the model did not decrease the predators' negative
impact on the population size and persistence of the endangered prey
when settlements occurred in many small patches. It is concluded that
predator management is not a viable strategy to combat the threat to
the survival of endangered prey, but that careful planning of
landscape pattern could compensate for negative predation effects.
The location and size of patches of predator habitat should be
optimized in order to minimize the negative effects of predators
visiting adjacent areas of natural habitat.
DE:
endangered-species; habitat-destruction; predator-preyrelationships; prey-; tundra-; wildlife-conservation
OD:
Clethrionomys-rufocanus; Felis-silvestris; Lemmus-; Mustelaerminea; Mustela-nivalis
ID:
landscape-architecture; Lemmus-lemmus; predator-control
BT:
Clethrionomys-; Microtinae-; Muridae-; rodents-; mammals-;
vertebrates-; Chordata-; animals-; small-mammals; Felis-; Felidae-;
Fissipeda-; carnivores-; Mustela-; MustelidaeCC:
PP710; YY500; ZZ332
CD:
Biological-Resources-Animal; Behaviour-Wild-Animals; AnimalEcology
PT:
Journal-article
IS:
0021-8901
UD:
200100
AN:
20013113781
SM:
OPS\P
TI:
Resident bird species in urban forest remnants; landscape and
habitat perspectives.
AU:
Mortberg,-U-M
AD:
Div. of Land- and Water Resources, Royal Institute of
Technology, S-100 44 Stockholm, Sweden.
SO:
Landscape-Ecology. 2001; 16(3): 193-203
PB:
Dordrecht, Netherlands: Kluwer Academic Publishers.
RE:
43 ref.
PY:
2001
LA:
English
AB:
The aim of this study was to investigate the effects of
habitat loss, fragmentation and habitat quality on sedentary forest
birds in an urban and suburban environment. The study area was
situated in Stockholm, the capital of Sweden, embracing the city
centre, suburbs and parts of the rural surroundings. Breeding forest
birds were surveyed in 51 forested sample sites (2-700 ha) and five
species of resident birds were selected for further studies: willow
tit (Parus montanus), crested tit (P. cristatus) and coal tit (P.
ater) representing coniferous forest (Picea abies and Pinus
sylvestris) and marsh tit (P. palustris) and nuthatch (Sitta
europaea) representing deciduous forest (Quercus robur, Betula
pendula and Populus tremula). A spatial landscape analysis was made
using a geographical information system. In 21 of the smaller sites
(2-200 ha), a field study was conducted to examine habitat quality
parameters like vegetation age, structure and composition, and humaninduced disturbance. The probability of occurrence (breeding) of bird
species as functions of landscape and habitat descriptors was tested
using logistic regression. All investigated species of the Parus
guild showed high probabilities of occurrence only in forest patches
larger than 200-400 ha, and was not present in patches smaller than
10-30 ha. This meant that patches of presumably suitable habitat
(coniferous vs. moist deciduous forest) were left unoccupied. The
amount of standing dead and decaying trees provided additional
explanation for the distribution of the willow tit. Large areas of
urban open land, industrial land use and large bodies of water had a
negative influence on the probability of occurrence of several
species, which indicate that they were sensitive to isolation. The
probability of occurrence of the marsh tit was also influenced by
distance to other sample sites with marsh tits. Unlike the Parus
species, the nuthatch was breeding in most of the parks and forest
remnants. This species prefers mature deciduous forest, mainly oak
(Q. robur), which habitat was common in the urban environment. The
nuthatch was only absent in some of the smallest (a few ha) forest
fragments, with a mean distance between forest patches in the
surroundings of over 100 m. The study showed that large forest areas
and a high amount of forest in the landscape are important for the
investigated resident birds that are not adapted to the urban
environment. Vast areas without tree-cover seemed to be poor habitat
and/or restrict dispersal. Strips of high-quality habitats, including
standing trees with nest-holes, were not entirely absent in the urban
and suburban environment.
DE:
coniferous-forests; dead-trees; deciduous-forests;
environmental-degradation; forest-fragmentation; forests-;
geographical-information-systems; habitat-destruction; habitats-;
stand-age; stand-structure; suburban-areas; trees-; urban-areas;
urbanization-; wild-birds; wildlife-conservation
OD:
Betula-pendula; birds-; Parus-; Passeriformes-; Picea-abies;
Pinus-sylvestris; Populus-tremula; Quercus-robur
GE:
SwedenID:
Parus-ater; Parus-cristatus; Parus-montanus; Parus-palustris;
Sitta-; Sitta-europaea; Sittidae-
BT:
Betula-; Betulaceae-; Fagales-; dicotyledons-; angiosperms-;
Spermatophyta-; plants-; Paridae-; Passeriformes-; birds-;
vertebrates-; Chordata-; animals-; Parus-; Picea-; Pinaceae-;
Pinopsida-; gymnosperms-; Pinus-; Populus-; Salicaceae-; Salicales-;
Quercus-; Fagaceae-; Scandinavia-; Northern-Europe; Europe-;
Developed-Countries; European-Union-Countries; OECD-Countries
CC:
KK100; PP600; PP710; YY500; ZZ332
CD:
Forests-and-Forest-Trees-Biology-and-Ecology; Pollution-andDegradation; Biological-Resources-Animal; Behaviour-Wild-Animals;
Animal-Ecology
PT:
Journal-article
IS:
0921-2973
UD:
200100
AN:
20013079145
TI:
Characteristics of insect populations on habitat fragments: a
mini review.
AU:
Tscharntke,-T; Steffan-Dewenter,-I; Kruess,-A; Thies,-C
AD:
Agroecology, University of Gottingen, Waldweg 26, D-37073
Gottingen, Germany.
EM:
[email protected]
SO:
Ecological-Research. 2002; 17(2): 229-239
PB:
Carlton South, Australia: Blackwell Science Asia.
RE:
many ref.
PY:
2002
LA:
English
AB:
Modern human-dominated landscapes are typically characterized
by intensive land-use and high levels of habitat destruction, often
resulting in sharply contrasted habitat mosaics. Fragmentation of
remaining habitat is a major threat to biodiversity. In the present
paper, we focus on the different features of habitat fragmentation.
First we discuss the importance of pure habitat loss, fragment size,
fragment isolation and quality, edge effects, and the importance of
landscape structure. Second, we characterize life-history features of
fragmentation-sensitive species, showing that rare, specialized,
little dispersing species are most affected, as well as species
characterized by high population variability and a high trophic
position, while the effect of body size is unclear. Third, we discuss
the conservation value of habitat fragments. The question arises how
to relate studies on population survival to those of community
structure and studies on biodiversity to those on ecological
functions. Despite the general superiority of large to small
reserves, only small or medium-sized reserves are available in many
human-dominated landscapes. A great number of small habitats covering
a wide range of geographic area should maximize beta diversity and
spreading of risk and may be very important for the regional
conservation of biodiversity, in contrast to the prevailing arguments
in favor of large habitats. Finally, landscape context influences
community structure of fragments, and communities are composed of
species that experience the landscape on a broad range of spatial
scales. Spatial arrangement of habitat fragments in a landscape
appears to be important only in simple, not complex landscapes.
DE:
biodiversity-; community-ecology; conservation-; habitatdestruction; habitats-; landscape-; life-history; nature-reserves;
reviewsOD:
insectsBT:
arthropods-; invertebrates-; animalsCC:
PP300; PP710; ZZ332
CD:
Land-Resources; Biological-Resources-Animal; Animal-Ecology
PT:
Journal-article
IS:
UD:
AN:
XURL:
0912-3814
200200
20023064495
E-MAIL
TI:
Landscape ecology and forest management: developing an
effective partnership.
AU:
Boutin,-S; Hebert,-D
AD:
Alberta Pacific Forest Industries Ltd., Department of
Biological Sciences, University of Alberta, Edmonton, Alberta T6G
2E9, Canada.
SO:
Ecological-Applications. 2002; 12(2): 390-397
PB:
Washington, USA: Ecological Society of America.
URL:
http://www.esajournals.org/esaonline/?request=getabstract&issn=1051-0761&volume=012&issue=02&page=0390
PY:
2002
LA:
English
AB:
Landscape ecologists have been eager to make their research
applicable to forest management. We examine how landscape ecology has
contributed to shaping the way forest management is currently
practiced. Landscape ecology research in forested ecosystems can be
divided into two general areas: (1) the study of fragmentation
issues, which focuses on the effects of forest fragmentation on
species conservation; and (2) the development of landscape projection
models, which focuses on patch dynamics and the effects of spatial
arrangement of patches on ecosystem processes. Fragmentation issues
have become priorities in the minds of forest managers, but research
to date has over-emphasized the effects of landscape structure on
species conservation. We suggest that the research focus should move
toward the study of threshold effects of landscape change on the
relative influence of habitat loss and habitat configuration on
species conservation in forest-dominated landscapes. Landscape
projection models are rapidly becoming important tools in forest
management planning, and they hold great promise as a means to bring
landscape ecologists and forest managers together. The ability to
produce future landscapes under different management scenarios and to
compare these to landscapes produced by natural disturbance regimes
will help to focus both managers and scientists on understanding the
key interactions among human activities, landscape features, and
ecological processes.
DE:
ecological-disturbance; forest-fragmentation; forestmanagement; forests-; landscape-ecology; nature-conservation
CC:
KK110; PP600; PP700
CD:
Silviculture-and-Forest-Management; Pollution-and-Degradation;
Biological-Resources-General
PT:
Journal-article
IS:
1051-0761
UD:
200309
AN:
20033119006
XURL: URL
TI:
Extinction debt at extinction threshold.
AU:
Hanski,-I; Ovaskainen,-O
AD:
Metapopulation Research Group, Department of Ecology and
Systematics, P.O. Box 65, Viikinkaari 1, FIN-00014, University of
Helsinki, Helsinki, Finland.
EM:
[email protected]
SO:
Conservation-Biology. 2002; 16(3): 666-673
PB:
Malden, USA: Blackwell Science, Inc..
RE:
26 ref.
DOI:
doi:10.1046/j.1523-1739.2002.00342.x
PY:
2002
LA:
English
LS:
Spanish
AB:
To allow for long-term metapopulation persistence, a network
of habitat fragments must satisfy a certain condition in terms of
number, size, and spatial configuration of the fragments. The
influence of landscape structure on the threshold condition can be
measured by a quantity called metapopulation capacity, which can be
calculated for real fragmented landscapes. Habitat loss and
fragmentation reduce the metapopulation capacity of a landscape and
make it less likely that the threshold condition can be met. If the
condition is not met, the metapopulation is expected to go extinct,
but it takes some time following habitat loss before the extinction
will occur, which generates an extinction debt in a community of
species. We show that extinction debt is especially great in a
community in which many species are close to their extinction
threshold following habitat loss because the metapopulation-dynamic
time delay is especially long in such species. A corollary is that
landscapes that have recently experienced substantial habitat loss
and fragmentation are expected to show a transient excess of rare
species, which represents a previously overlooked signature of
extinction debt. We consider a putative example of extinction debt on
forest-inhabiting beetles in Finland. At present, the few remaining
natural-like forests are distributed evenly throughout southern
Finland, but the number of regionally extinct old-growth forest
beetles is much greater in the southwestern coastal areas, where
human impact on forests has been lengthy, than in the northeastern
inland areas, where intensive forestry started only after World War
II. Ignoring time delays in population and metapopulation dynamics
will lead to an underestimate of the number of effectively endangered
species.
DE:
endangered-species; extinction-; forest-fragmentation;
forests-; habitat-destruction; habitat-selection; habitats-; insectcommunities; landscapeOD:
Coleoptera-; insectsGE:
FinlandBT:
insects-; arthropods-; invertebrates-; animals-; Scandinavia-;
Northern-Europe; Europe-; Developed-Countries; European-UnionCountries; OECD-Countries
CC:
KK100; PP600; PP710; PP720; YY500; ZZ331; ZZ332
CD:
Forests-and-Forest-Trees-Biology-and-Ecology; Pollution-andDegradation; Biological-Resources-Animal; Biological-Resources-Plant;
Behaviour-Wild-Animals; Plant-Ecology; Animal-Ecology
PT:
Journal-article
IS:
0888-8892
UD:
200300
AN:
20023089120
SM:
OPS/P
XURL: E-MAIL; DOI; DIGITAL-OBJECT-IDENTIFIER
TI:
Two genetically distinct units of the Chinese sika deer
(cervus nippon): analyses of mitochondrial DNA variation.
AU:
Wu-Hua; Wan-QiuHong; Fang-ShengGuo
AD:
College of Life Sciences, Zhejiang University, No. 268 Kai
Xuan Road, Hangzhou 310029, Zhejiang, China.
EM:
[email protected]
SO:
Biological-Conservation. 2004; 119(2): 183-190
PB:
Oxford, UK: Elsevier Science Ltd.
RE:
22 ref.
PY:
2004
LA:
English
AB:
Chinese sika deer, Cervus nippon, are currently threatened by
habitat loss, fragmentation and human hunting, which has led to the
extinction of three subspecies in the wild. The remaining subspecies
subsist in the narrow regions of Jilin, Heilongjiang, Sichuan, Gansu,
Jiangxi, Anhui, and Zhejiang provinces. In order to design effective
conservation strategies for the Chinese sika deer, we have
investigated genetic diversity, population structure and gene flow in
the Chinese sika deer populations by analyzing ~995 base pairs of the
mitochondrial DNA (mtDNA) control region in 59 individuals sampled
from the northeast of China, Sichuan, Jiangxi and Zhejiang. Chinese
sika deer exhibited low mtDNA diversity and high gene flow among the
four populations, and showed no strong geographical structure. The
analyses of mtDNA variation among individuals of sika deer identified
only two main phylogenetic groups even though three subspecies were
sampled. These data singles out the Zhejiang population as being
highly genetically distinct and worthy of separate conservation
consideration. Therefore, it is recommended that a breeding program
for the Zhejiang population be established.
DE:
endangered-species; gene-flow; genetic-diversity;
mitochondrial-DNA; nucleotide-sequences; phylogeny-; populationstructure; wildlife-conservation
OD:
Cervus-nippon
GE:
ChinaBT:
Cervus-; Cervidae-; ruminants-; Artiodactyla-; mammals-;
vertebrates-; Chordata-; animals-; ungulates-; East-Asia; Asia-;
Developing-Countries
CC:
LL240; PP710; YY300; ZZ360; ZZ380
CD:
Animal-Genetics-and-Breeding; Biological-Resources-Animal;
Genetics-and-Molecular-Genetics-Wild-Animals; Molecular-Biology-andMolecular-Genetics; Taxonomy-and-Evolution
PT:
Journal-article
IS:
0006-3207
UD:
200410
AN:
20043142698
XURL: E-MAIL
TI:
Allegheny woodrat (Neotoma magister) use of rock drainage
channels on reclaimed mines in Southern West Virginia.
AU:
Chamblin,-H-D; Wood,-P-B; Edwards,-J-W
AD:
USGS West Virginia Cooperative Fish and Wildlife Research
Unit, West Virginia University, Division of Forestry, P.O. Box 6125,
Morgantown, WV 26506, USA.
EM:
[email protected] [email protected] [email protected]
SO:
American-Midland-Naturalist. 2004; 151(2): 346-354
PB:
Notre Dame, USA: University of Notre Dame Press.
RE:
24 ref.
PY:
2004
LA:
English
AB:
Allegheny woodrats (Neotoma magister) currently receive
protected status throughout their range due to population declines.
Threats associated with habitat fragmentation (e.g., introduced
predators, disease, loss of connectivity among sub-populations and
habitat loss) may explain why Allegheny woodrats are no longer found
in many areas where they existed just 25 years ago. In southern West
Virginia (USA), surface coal mining is a major cause of forest
fragmentation. Furthermore, mountaintop mining, the prevalent method
in the region, results in a loss of rock outcrops and cliffs within
forested areas, typical habitat of the Allegheny woodrat. To
determine the extent that Allegheny woodrats make use of reclaimed
mine land, particularly rock drainages built during reclamation, we
sampled 24 drainage channels on reclaimed surface mines in southern
West Virginia, collected habitat data at each site and used logistic
regression to identify habitat variables related to Allegheny woodrat
presence. During 187 trap nights, 13 adult, 2 subadult and 8 juvenile
Allegheny woodrats were captured at 13 of the 24 sites. Percent of
rock as a groundcover and density of stems >15 cm diameter at breast
height were related to Allegheny woodrat presence and were
significantly greater at sites where Allegheny woodrats were present
than absent. Sites where Allegheny woodrats were present differed
substantially from other described habitats in West Virginia, though
they may simulate boulder piles that occur naturally. Our findings
suggest the need for additional research to examine the dynamics
between Allegheny woodrat populations inhabiting rock outcrops in
forests adjacent to mines and populations inhabiting constructed
drainage channels on reclaimed mines. However, if Allegheny woodrats
can use human-created habitat, our results will be useful to surface
mine reclamation and to other mitigation efforts where rocky habitats
are lost or disturbed.
DE:
animal-behaviour; drainage-channels; endangered-species;
habitat-selection; habitats-; mined-land; reclaimed-land;
reclamation-; wild-animals; wildlife-conservation
OD:
NeotomaGE:
USA-; West-Virginia
ID:
Neotoma-magister
BT:
Hesperomyinae-; Muridae-; rodents-; mammals-; vertebrates-;
Chordata-; animals-; small-mammals; North-America; America-;
Developed-Countries; OECD-Countries; Appalachian-States-of-USA;
Southern-States-of-USA; USA-; South-Atlantic-States-of-USA
CC:
KK100; PP710; YY500; ZZ332
CD:
Forests-and-Forest-Trees-Biology-and-Ecology; BiologicalResources-Animal; Behaviour-Wild-Animals; Animal-Ecology
PT:
Journal-article
IS:
0003-0031
UD:
200406
AN:
20043072814
XURL: E-MAIL
TI:
Capercaillie Tetrao urogallus - a good candidate for an
umbrella species in the taiga forests.
AU:
Pakkala,-T; Pellikka,-J; Linden,-H
ED:
Storch,-I
AD:
Finnish Museum of Natural History, University of Helsinki, PO
Box 17, FIN-00014, Finland.
EM:
[email protected] [email protected]
[email protected]
SO:
Wildlife-Biology. 2003; 9(4): 309-316
PB:
Ronde, Denmark: Nordic Council for Wildlife Research.
CF:
9th International Grouse Symposium, Beijing, China, 18-23
August 2002.
RE:
26 ref.
PY:
2003
LA:
English
AB:
The capercaillie Tetrao urogallus is widely accepted as a
species seriously suffering from fragmentation of forests and habitat
loss. Foresters as well as conservationists agree on the need and
principles for maintaining viable populations, but the proposed
management means often differ. The approach currently favoured by
Finnish foresters is to manage capercaillie leks and their
surroundings using methods that differ from those used in intensive
forestry. It may be desirable to prove that forests with capercaillie
leks also favour other forest bird species and biodiversity in
general. During the last 16 years (1987-2002), forest birds have been
censused and capercaillie leks were mapped in the 465-km2 study area
in southern Finland. Most of the study area consists of
sprucedominated mature forests. The remainder of the landscape is a
mixture of variously aged forests, agricultural areas, lakes and
scattered human settlements with a gradient from an agriculturalforest mosaic to forest-dominated areas. The old-growth forest bird
species three-toed woodpecker Picoides tridactylus, pygmy owl
Glaucidium passerinum and red-breasted flycatcher Ficedula parva were
more abundant within 300 m and 1,000 m radii around capercaillie lek
sites than in non-lek control sites. Also the overall species
richness of breeding forest birds was higher in the vicinity of
capercaillie leks. On a larger scale (100x100 km squares), using the
wildlife triangle scheme developed in Finland, we show that the
density of capercaillie closely coincides with a wildlife richness
index describing the total abundance of 15 other forestdwelling
mammal and bird species with diverse ecology and habitat
requirements. Capercaillie is a flagship species for foresters, and
can be considered a good candidate for an umbrella species for
wildlife in taiga forests.
DE:
boreal-forests; forests-; habitats-; old-growth-forests;
population-density; species-richness; wild-birds
OD:
birds-; Ficedula-; Picoides-; Tetrao-urogallus
GE:
FinlandID:
Ficedula-parva; Glaucidium-passerinum; Picoides-tridactylus
BT:
Muscicapidae-; Passeriformes-; birds-; vertebrates-; Chordata; animals-; Ficedula-; Scandinavia-; Northern-Europe; Europe-;
Developed-Countries; European-Union-Countries; OECD-Countries;
Picidae-; Piciformes-; Picoides-; Tetrao-; Phasianidae-; GalliformesCC:
KK100; ZZ332
CD:
Forests-and-Forest-Trees-Biology-and-Ecology; Animal-Ecology
PT:
Journal-article; Conference-paper
IS:
0909-6396
UD:
200403
AN:
20043025884
XURL: E-MAIL
TI: Response of predators to loss and fragmentation of prey habitat:
a review of theory.
AU: Ryall,-K-L; Fahrig,-L
SO: Ecology-. 2006; 87(5): 1086-1093
PB: Washington, USA: Ecological Society of America.
URL: http://www.esajournals.org/perlserv/?request=getdocument&doi=10.1890%2F00129658%282006%2987%5B1086%3AROPTLA%5D2.0.CO%3B2
LA: English
AB: Despite extensive empirical research and previous reviews, no
clear patterns regarding the effects of habitat loss and
fragmentation on predator-prey interactions have emerged. We suggest
that this is because empirical researchers do not design their
studies to test specific hypotheses arising from the theoretical
literature. In fact, theoretical work is almost completely ignored by
empirical researchers, perhaps because it may be inaccessible to
them. The purpose of this paper is to review theoretical work on the
effects of habitat loss and fragmentation on predator-prey
interactions. We provide a summary of clear, testable theoretical
predictions for empirical researchers. To test one or more of these
predictions, an empiricist will need certain information on the
predator and prey species of interest. This includes: (1) whether the
predator is a specialist on one prey species or feeds on many kinds
of prey (omnivore and generalist); (2) whether the predator is
restricted to the same habitat type as the focal prey (specialist),
can use a variety of habitats but has higher survival in the prey
habitat (omnivore), or lives primarily outside of the focal prey's
habitat (generalist); (3) whether prey-only patches have lower prey
extinction rates than predator-prey patches; and (4) whether the prey
emigrate at higher rates from predator-prey patches than from preyonly patches. Empiricists also need to be clear on whether they are
testing a prediction about habitat loss or habitat fragmentation and
need to conduct empirical studies at spatial scales appropriate for
testing the theoretical prediction(s). We suggest that appropriate
use of the theoretical predictions in future empirical research will
resolve the apparent inconsistencies in the empirical literature on
this topic.
PT: Journal-article
AN: 20073243125
TI: Landscape genetics of Physalaemus cuvieri in Brazilian cerrado:
correspondence between population structure and patterns of human
occupation and habitat loss.
AU: Telles,-M-P-de-C; Diniz-Filho,-J-A-F; Bastos,-R-P; Soares,-T-N;
Guimaraes,-L-D; Lima,-L-P
SO: Biological-Conservation. 2007; 139(1/2): 37-46
PB: Oxford, UK: Elsevier.
URL: http://www.sciencedirect.com/science/journal/00063207
LA: English
AB: It is now widely recognized that knowledge on population genetic
structure is important to evaluate population viability and
persistence or to establish conservation priorities. In this context,
species that are locally abundant or widely distributed can be
informative on how broad scale processes of habitat loss and
fragmentation, as those caused by intensive human occupation, affect
population genetic structure. In this paper, we analyzed population
genetic structure of Physalaemus cuvieri (Amphibia: Leptodactylidae)
in the core of the Cerrado biome, in the Goias State, Central Brazil,
using RAPD molecular markers. Local populations are genetically
different according to RAPD markers, and an analysis of molecular
variation (AMOVA) revealed a significant interpopulational variance
component around 10%. However, these population differentiation
patterns are not strongly structured in geographic space, and a
Mantel spatial correlogram indicated only a slight significant
spatial structure at short geographic distances. These patterns are
expected by the ecological and life-history knowledge of the species,
leading to a relatively low magnitude of population differentiation
coupled with short distance spatial patterns. Moreover, even these
weak patterns showed a signature of effects of human occupation and
habitat loss on genetic differentiation at regional scale, with
discontinuities to gene flow in two particular regions of the State
with more intense habitat loss and older human settlement.
PT: Journal-Article
AN: 20073211400
TI: The montane grasslands of the Western Ghats, India: community
ecology and conservation.
AU: Thomas,-S-M; Palmer,-M-W
SO: Community-Ecology. 2007; 8(1): 67-73
PB: Budapest, Hungary: Akademiai Kiado.
URL: http://www.terra.hu/comecol
LA: English
AB: The montane (shola) grasslands of Western Ghats, South India are
a component of a landscape mosaic including the better-studied shola
forests. The conservation of the grasslands depends upon
understanding their ecology. This review compiles available
information and aims to evaluate the conservation potential of these
grasslands. Most studies on these grasslands are descriptive in
nature. There is little information regarding habitat heterogeneity,
landscape configuration, natural disturbance, grazing and
productivity in maintaining the grasslands. Succession is poorly
understood because of the short-term nature of most studies. Human
activities have historically influenced these grasslands and will
continue to do so in more intensive manner. Threats to these
grasslands include habitat loss, fragmentation, fires, and invasive
species.
PT: Journal-Article
AN: 20073161513
TI: Impact assessment and biodiversity considerations in Nigeria: a
case study of Niger Delta University campus project on wildlife in
Nun River Forest Reserve.
AU: Hamadina,-M-K; Otobotekere,-D; Anyanwu,-D-I
SO: Management-of-Environmental-Quality. 2007; 18(2): 179-197
PB: Bradford, UK: Emerald Group Publishing Ltd.
URL: http://www.emeraldinsight.com/info/journals/meq/meq.jsp
LA: English
AB: The Niger Delta University (NDU) campus is located on the fringe
of the Nun River Forest Reserve (NRFR) in Nigeria. The NRFR covers
97.15 km2 of humid tropical rain forest characterized by torrential
rains, seasonal flooding, and multi-layered vegetation. This paper
reports the results of an original work, discusses the impacts of the
NDU campus on NRFR, highlights conservation-friendly local
beliefs/practices that could fit into a wildlife management plan, and
fosters the debate on methodologies and field initiatives. The study
aimed to conduct a wildlife investigation to assess the effects of
the NDU campus project on NRFR. The assessment was preceded by
scoping to determine key wildlife issues. Thereafter, a mix of
methods, including literature search, reconnaissance visits, field
exercises, and interviews with hunters, was adopted to gather
information. These were augmented with diurnal and nocturnal forest
expeditions to find evidences of wildlife species existence. There
was a rich assemblage of wildlife species, of which 12 are enlisted
in the 2006 IUCN Red List of threatened species and 14 are protected
by Nigeria's statutes, and they are threatened by human activities.
The NDU campus project shall have significant adverse impacts on the
wildlife: directly through habitat loss/fragmentation, nuisance and
influx of people; and indirectly by exacerbating the existing
threats. This work is limited to the NDU campus project and its
impact on NRFR. The brevity of time spent in the field coupled with
the generally inaccessible terrain and remote location of the NRFR
constitute the limitations that must have influenced the findings of
this study.
PT: Journal-Article
AN: 20073124656
TI: Habitat loss, fragmentation, and alteration - quantifying the
impact of land-use changes on a Spanish dehesa landscape by use of
aerial photography and GIS.
AU: Plieninger,-T
SO: Landscape-Ecology. 2006; 21(1): 91-105
PB: Dordrecht, Netherlands: Springer Science + Business Media.
URL: http://springerlink.metapress.com/link.asp?id=103025
LA: English
AB: Mediterranean agroforestry landscapes, dehesas, experience
significant structural changes that affect their ability to support
habitats for a rich biodiversity. The goal of this study was to
provide quantitative information on loss, fragmentation, and
alteration of holm oak (Quercus ilex) stands over a 42-year period,
based on two sites in the lowlands of Caceres province, Spain. Aerial
photography and orthoimages from 1956, 1984, and 1998 were processed
in a geographic information system (GIS). Important changes in
demography and land-use were rural depopulation, abandonment of
traditional agricultural activities, and a sharp increase in
livestock stocking levels. These were related to intensification and
extensification of land-uses determined by national and EU
agricultural policies. Results of the land cover analysis indicated
that dehesas suffered an annual 0.27 and 0.04% decrease in cover in
the two sites. From 1984 loss rate had markedly accelerated (0.83 and
0.30%). Most dehesas were lost by shrub encroachment or conversion to
open grassland. Fragmentation through roads increased by 28 and 45%,
while rural buildings decreased by 17 and 50% from 1956 to 1998. Mean
tree density decreased from 1956 to 1984, but a recovery was found
since 1984. Significant factors determining stand densities in most
time points were altitude (related with different land-uses and
geological substrates), ownership, and proximity to villages. This
suggests that stand structure is controlled both by human
interventions and ecological settings. The findings support the view
that opposite trends of land abandonment and intensification of landuses arise in most northern Mediterranean countries as an effect of
the EU Common Agricultural Policy.
PT: Journal-article
AN: 20063115480
TI: The roles of landscape context, niche breadth, and range
boundaries in predicting species responses to habitat alteration.
AU: Swihart,-R-K; Lusk,-J-J; Duchamp,-J-E; Rizkalla,-C-E; Moore,-J-E
SO: Diversity-and-Distributions. 2006; 12(3): 277-287
PB: Oxford, UK: Blackwell Publishing.
URL: http://www.blackwellsynergy.com/servlet/useragent?func=showIssues&code=ddi
LA: English
AB: Extant species in human-dominated landscapes differ in their
sensitivity to habitat loss and fragmentation, although extinctions
induced by environmental alteration reduce variation and result in a
surviving subset of species with some degree of 'resistance'. Here,
we test the degree to which variable responses to habitat alteration
are (1) essentially an inherent property of a taxon subject to
constraints imposed by its geographical range, as suggested by
Swihart et al. (2003), (2) a function of the landscape in which a
species occurs, or (3) a function of spatial trends occurring on
large scales. We used data collected on 33 vertebrate species during
2001-04 across the upper Wabash River basin, Indiana, in 35 square
'landscapes', each 23 km2 in size. Six species of forest rodent, six
species of grassland rodents, seven species of bats, eight species of
aquatic turtles, and six species of amphibians were sampled at 504,
212, 590, 228, and 625 patches, respectively. The fraction of patches
of primary habitat (e.g. forests for tree squirrels, wetlands for
aquatic turtles) occupied by a target species was used as a response
variable. On a basin-wide scale, 47% of variation in proportional
occupancy among species could be explained by taxon-specific
variables; occupancy rates were related positively to niche breadth
and negatively to the proximity of a geographical range boundary.
After controlling for species effects, landscape-level occupancy
rates varied significantly for 16 of 33 species, with variation
partitioned among landscape variables alone (mean=11% of variation),
spatial trend variables alone (26%), and both variable sets jointly
(8%). Among landscape variables, percentage forest cover positively
affected occupancy rates of three bat species and a tree squirrel.
Variation in occupancy rates among landscapes was consistent with
large-scale spatial trends for 13 species. Our findings demonstrate
the general importance of niche breadth as a predictor of species
responses to habitat alteration and highlight the importance of
viewing the effects of habitat loss and fragmentation at multiple
spatial scales.
PT: Journal-article
AN: 20063103753
TI: Confounding factors in the detection of species responses to
habitat fragmentation.
AU: Ewers,-R-M; Didham,-R-K
SO: Biological-Reviews. 2006; 81(1): 117-142
PB: Cambridge, UK: Cambridge University Press.
URL: http://journals.cambridge.org/
LA: English
AB: Habitat loss has pervasive and disruptive impacts on
biodiversity in habitat remnants. The magnitude of the ecological
impacts of habitat loss can be exacerbated by the spatial arrangement
- or fragmentation - of remaining habitat. Fragmentation per se is a
landscape-level phenomenon in which species that survive in habitat
remnants are confronted with a modified environment of reduced area,
increased isolation and novel ecological boundaries. The implications
of this for individual organisms are many and varied, because species
with differing life history strategies are differentially affected by
habitat fragmentation. Here, we review the extensive literature on
species responses to habitat fragmentation, and detail the numerous
ways in which confounding factors have either masked the detection,
or prevented the manifestation, of predicted fragmentation effects.
Large numbers of empirical studies continue to document changes in
species richness with decreasing habitat area, with positive,
negative and no relationships regularly reported. The debate
surrounding such widely contrasting results is beginning to be
resolved by findings that the expected positive species-area
relationship can be masked by matrix-derived spatial subsidies of
resources to fragment-dwelling species and by the invasion of matrixdwelling species into habitat edges. Significant advances have been
made recently in our understanding of how species interactions are
altered at habitat edges as a result of these changes. Interestingly,
changes in biotic and abiotic parameters at edges also make
ecological processes more variable than in habitat interiors.
Individuals are more likely to encounter habitat edges in fragments
with convoluted shapes, leading to increased turnover and variability
in population size than in fragments that are compact in shape.
Habitat isolation in both space and time disrupts species
distribution patterns, with consequent effects on metapopulation
dynamics and the genetic structure of fragment-dwelling populations.
Again, the matrix habitat is a strong determinant of fragmentation
effects within remnants because of its role in regulating dispersal
and dispersal-related mortality, the provision of spatial subsidies
and the potential mediation of edge-related microclimatic gradients.
We show that confounding factors can mask many fragmentation effects.
For instance, there are multiple ways in which species traits like
trophic level, dispersal ability and degree of habitat specialisation
influence species-level responses. The temporal scale of
investigation may have a strong influence on the results of a study,
with short-term crowding effects eventually giving way to long-term
extinction debts. Moreover, many fragmentation effects like changes
in genetic, morphological or behavioural traits of species require
time to appear. By contrast, synergistic interactions of
fragmentation with climate change, human-altered disturbance regimes,
species interactions and other drivers of population decline may
magnify the impacts of fragmentation. To conclude, we emphasise that
anthropogenic fragmentation is a recent phenomenon in evolutionary
time and suggest that the final, long-term impacts of habitat
fragmentation may not yet have shown themselves.
PT: Journal-article
AN: 20063044677
TI: Landscapes, ecology and wildlife management in highly modified
environments - an Australian perspective.
AU: Hobbs,-R-J
SO: Wildlife-Research. 2005; 32(5): 389-398
PB: Collingwood, Australia: CSIRO Publishing.
LA: English
AB: Landscapes in southern Australia have been extensively modified
by a variety of human activities, predominantly agriculture and urban
development. Over much of the area, native vegetation has been
replaced with agriculture or buildings and infrastructure. A
continuum exists from areas that remain largely intact, but are
modified in some way (e.g. forests managed for timber production), to
areas where the remaining native vegetation is fragmented to varying
degrees. Habitat management will vary across this continuum,
depending on the degree of habitat loss and isolation. In areas
outside the main zones of agricultural and urban development, the
process of habitat loss and fragmentation is less in evidence. Here,
instead, the landscapes remain apparently structurally intact, in
that the native vegetation is not actually removed. However, these
landscapes have also, in many cases, been significantly modified,
particularly by pastoralism and related activities, to the extent
that their value as habitat is impaired. Declining habitat value in
northern landscapes may lead to the same types of functional
fragmentation as found in the south. An examination of the
differences and similarities between southern and northern landscapes
can highlight what can be learned from the southern experience which
may be of value in savanna landscapes. In both cases, the importance
of considering impacts in relation to species-specific responses
needs to be emphasised.
PT: Journal-article; Conference-paper
AN: 20053187204
TI: Genetic diversity and conservation of common wild rice (Oryza
rufipogon) in China.
AU: Song-ZhiPing; Li-Bo; Chen-JiaKuan; Lu-BaoRong
SO: Plant-Species-Biology. 2005; 20(2): 83-92
PB: Melbourne, Australia: Blackwell Publishing.
URL: http://www.blackwellsynergy.com/servlet/useragent?func=showIssues&code=psb
LA: English
AB: Common wild rice (Oryza rufipogon Griff.), known as the ancestor
of Asian cultivated rice (Oryza sativa L.), is the most important
germplasm for rice improvement. The first male sterility gene was
found in the wild rice, and introduced to the cultivated rice, which
launched the fast development of the high-yielding hybrid rice. Other
agronomically beneficial traits in the wild rice, such as rice tungro
virus resistance, bacterial leaf blight (Xa21 gene) resistance and
acid sulfate soil tolerance, have played important roles in rice
breeding. China has the northernmost distribution area of wild rice
possessing great genetic diversity. However, most of the populations
of this species have disappeared in China over the last three
decades, mainly caused by habitat loss, fragmentation and other human
disturbances. Unfortunately, the decline of existing populations
still continues. In the present study, we reviewed studies on genetic
diversity and conservation of this wild rice in China, concentrating
on population structure, pollen competition, pollen/gene flow from
cultivated rice to wild rice, and ecological restoration in relation
to in situ conservation. The relatively high genetic diversity of
populations of O. rufipogon in China suggests that there is great
value for conservation. Considerable gene flow from cultivated rice
to wild rice may alter the genetic structure of natural populations
of O. rufipogon and eventually lead to its genetic erosion. Pollen
competition between wild and cultivated rice has caused a low rate of
crop-to-wild gene flow, but it does not completely prevent gene flow
from the crop. Effective isolation measures should be undertaken in
the regions where in situ conservation of O. rufipogon is carried
out. Reintroduction is an important alternative for the in situ
conservation of wild rice species. As wild rice is an important
genetic resource, both in situ and ex situ conservation strategies
are needed.
PT: Journal-article
AN: 20053143380
TI: Influence of former cultivation on the unique Mediterranean
steppe of France and consequences for conservation management.
AU: Romermann,-C; Dutoit,-T; Poschlod,-P; Buisson,-E
SO: Biological-Conservation. 2005; 121(1): 21-33
PB: Oxford, UK: Elsevier Science Ltd.
URL: http://www.sciencedirect.com/science/journal/00063207
LA: English
AB: In Europe, the actual landscape has been mainly influenced by
human activities. Agricultural intensification led to a considerable
habitat loss and fragmentation, especially for dry semi-natural
grasslands. This current study investigates the impact of former
melon and cereal cultivation (cultivation period: 1950-1987) on the
semi-natural vegetation of the Crau, representing the last xeric
Mediterranean steppe in France. Today, the ex-cultivated melon and
cereal fields are characterised by different vegetation compositions,
species richness and evenness compared to the undisturbed steppe
community. Also the abiotic conditions (N, P, K, pH, soil granule
fractions) have been changed by former cultivation practices. The
rather transient seed bank of the steppe was depleted during the
cultivation periods; ancient weed species and ruderals now determine
the seed bank of the ex-cultivated fields. It is concluded that the
conservation of the last parts of undisturbed steppe must have
absolute priority. A re-development of the original and unique steppe
community on formerly cultivated fields may take decades or
centuries, if at all.
PT: Journal-article
AN: 20053050362
Title: Apparent avian extinctions from islands in a man-made lake, South Africa
Authors: Dean, W.R.J.; Bond, W.J.
From: Ostrich, Vol 65, Issue 1, Mar
Published: 1994
Pages: p.7-13
Subjects: Avian diversity -- Hendrik Verwoerd Dam -- Isolated bird populations -- Natural
habitats -- Ornithology
ISSN: 0030-6525
Indexed by: ISAP
Abstract: Surveys avian diversity and abundance on islands in the Hendrik Verwoerd Dam,
comparing species lists on islands with matched sites on the mainland. Species counts were
lower on islands than on the mainland. Shows that habitat fragmentation can cause rapid
species loss and that the persistence of species in habitat fragments depends on corridors
over which birds are willing to fly. Includes figures
Title: Loss and fragmentation of habitat for pastoral people and wildlife in east Africa:
concepts and issues
Authors: Reid, R.S.; Thornton, P.K.; Kruska, R.L.
From: African journal of range and forage science, Vol 21, Issue 3, Dec
Published: 2004
Pages: p.171-181
Subjects: Case studies -- East Africa -- Fragmentation -- Habitat -- Landscape fragmentation
-- Pastoral lands -- Pastoral people -- Pastoral systems -- Rangeland ecosystems -- Wildlife
ISSN: 1022-0119
Indexed by: ISAP
Abstract: Explores the relatively uncharted area of rangeland loss and fragmentation in east
Africa. Discusses these issues with respect to east African pastoral systems to better
understand the causes and consequences of habitat loss and fragmentation from the
perspective of people, their livestock ad wildlife. Highlights unresolved issues that require
further thought and testing