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this PDF file
... concept in literature [1] however the most commonly used by most biologists is a group of organisms that are able to exchange genes within themselves but are reproductively isolated from other such groups. It means that there is no gene flow between two of such community [2]. They have separate ance ...
... concept in literature [1] however the most commonly used by most biologists is a group of organisms that are able to exchange genes within themselves but are reproductively isolated from other such groups. It means that there is no gene flow between two of such community [2]. They have separate ance ...
Histological Description of the Male and Female Gonads in Tegula
... dioecious, without external sexual dimorphism; in adults, the female gonads are green moss colored while male gonads are cream colored. The gonadal tissue is limited externally by a single ciliated cylindrical epithelium with plentiful granular glandular cells and is located on a connective tissue a ...
... dioecious, without external sexual dimorphism; in adults, the female gonads are green moss colored while male gonads are cream colored. The gonadal tissue is limited externally by a single ciliated cylindrical epithelium with plentiful granular glandular cells and is located on a connective tissue a ...
How functional is functional? Ecological groupings in terrestrial
... categorize groups. First, using attributes of species’ responses to environmental conditions (functional response group/type) and second, applying attributes of species’ effects on their environment (functional effect group/type) (Diaz and Cabido 2001). The resource-centred approach EGs in animal ec ...
... categorize groups. First, using attributes of species’ responses to environmental conditions (functional response group/type) and second, applying attributes of species’ effects on their environment (functional effect group/type) (Diaz and Cabido 2001). The resource-centred approach EGs in animal ec ...
Succession: A Closer Look
... successional changes. For example, The Resource Ratio Hypothesis, proposed by David Tilman (1985), models successional shifts in plant communities based on the assumption that succession is driven by a tradeoff in competition for nutrients in early succession, and for light in late succession. Other ...
... successional changes. For example, The Resource Ratio Hypothesis, proposed by David Tilman (1985), models successional shifts in plant communities based on the assumption that succession is driven by a tradeoff in competition for nutrients in early succession, and for light in late succession. Other ...
Despite its inhospitable appearance and lack of
... active or passive dispersion, accidentally penetrate underground. They are therefore occasional guests in this habitat, to which they are generally carried by water percolating from the surface. This situation is very frequent in surface and underground karstic aquifers, with infiltration passages w ...
... active or passive dispersion, accidentally penetrate underground. They are therefore occasional guests in this habitat, to which they are generally carried by water percolating from the surface. This situation is very frequent in surface and underground karstic aquifers, with infiltration passages w ...
Ant diversity in an Amazonian savanna: Relationship - PPBio
... precipitation is less than 65 mm on average (Santarém airport records, 1984–2002). The incidence of fires is high during the dry season, particularly towards the end of the season. Most of the region is covered by semideciduous forest or by patches of savanna. The latter are floristically similar to ...
... precipitation is less than 65 mm on average (Santarém airport records, 1984–2002). The incidence of fires is high during the dry season, particularly towards the end of the season. Most of the region is covered by semideciduous forest or by patches of savanna. The latter are floristically similar to ...
global strategy for addressing the problem of invasive alien species
... world. Indeed, the lives of people everywhere have been greatly enriched by being able to gain access to a greater share of the world's biological diversity. Expanding global trade is providing additional opportunities for further such enrichment, as well as imposing new species on ecosystems. 2. A ...
... world. Indeed, the lives of people everywhere have been greatly enriched by being able to gain access to a greater share of the world's biological diversity. Expanding global trade is providing additional opportunities for further such enrichment, as well as imposing new species on ecosystems. 2. A ...
The Serengeti food web: empirical quantification and analysis of
... resources as rows, both ordered by increasing body mass (Cohen 1978; Petchey et al. 2008a). Interactions in the upper-right triangle above the diagonal therefore indicate consumers feeding on resources smaller than themselves, a pattern often found in empirical food webs (‘upper-triangularity’, Warr ...
... resources as rows, both ordered by increasing body mass (Cohen 1978; Petchey et al. 2008a). Interactions in the upper-right triangle above the diagonal therefore indicate consumers feeding on resources smaller than themselves, a pattern often found in empirical food webs (‘upper-triangularity’, Warr ...
The community context of species` borders: ecological and
... of sympatry between the two species, and that Allee effects tend to sharpen these boundaries. We generalize these simple models to include metapopulation dynamics and other types of interactions including predator /prey and host-parasite interactions. We derive conditions for range limits in each c ...
... of sympatry between the two species, and that Allee effects tend to sharpen these boundaries. We generalize these simple models to include metapopulation dynamics and other types of interactions including predator /prey and host-parasite interactions. We derive conditions for range limits in each c ...
The interplay between environmental conditions and Allee effects
... Demographic stochasticity is not typically classified as an Allee effect because it does not directly impact individual fitness (Stephens et al. 1999). Instead, demographic stochasticity works at the population level by increasing extinction risk (Lande et al. 2003). Demographic stochasticity operat ...
... Demographic stochasticity is not typically classified as an Allee effect because it does not directly impact individual fitness (Stephens et al. 1999). Instead, demographic stochasticity works at the population level by increasing extinction risk (Lande et al. 2003). Demographic stochasticity operat ...
Network position of hosts in food webs and their parasite diversity
... theoretical problems in ecology (Pimm 1982). The small size makes them difficult to detect and invasive techniques are often required to study parasites inside their hosts. Small parasites consuming their much larger hosts (Leaper and Huxham 2002) is also distinct from the majority of trophic intera ...
... theoretical problems in ecology (Pimm 1982). The small size makes them difficult to detect and invasive techniques are often required to study parasites inside their hosts. Small parasites consuming their much larger hosts (Leaper and Huxham 2002) is also distinct from the majority of trophic intera ...
Chapter 5
... on Live Organisms of Other Species All organisms must have a source of food to survive. Recall that members of producer species, such as plants and floating phytoplankton, make their own food, mostly through photosynthesis (p. 58). Other species are consumers that interact with some species by feedi ...
... on Live Organisms of Other Species All organisms must have a source of food to survive. Recall that members of producer species, such as plants and floating phytoplankton, make their own food, mostly through photosynthesis (p. 58). Other species are consumers that interact with some species by feedi ...
Studying insect diversity in the tropics
... Wagner 1997); in Asia (e.g. Morse et al. 1988; Stork 1988, 1991; Hammond et al. 1997); and in Australia (e.g. Basset & Kitching 1991). The studies show an inordinate fondness for beetles, although other groups have also been examined and a few studies have surveyed the full spectrum of insects (e.g. ...
... Wagner 1997); in Asia (e.g. Morse et al. 1988; Stork 1988, 1991; Hammond et al. 1997); and in Australia (e.g. Basset & Kitching 1991). The studies show an inordinate fondness for beetles, although other groups have also been examined and a few studies have surveyed the full spectrum of insects (e.g. ...
this PDF file - Florida Online Journals
... Sources of variation in apparency and aesthetic appeal in insects include adaptations associated with the environment, particular life history strategies, predator defense, sexual selection, and the interplay of these. Population and species differences in size, shape, and coloration can reflect var ...
... Sources of variation in apparency and aesthetic appeal in insects include adaptations associated with the environment, particular life history strategies, predator defense, sexual selection, and the interplay of these. Population and species differences in size, shape, and coloration can reflect var ...
ecological differentiation between sympatric pseudocryptic species
... Sampling sites and clonal cultures. In addition to the 11 N. phyllepta strains used by Créach et al. (2006) (strain designations beginning with ‘‘CCY’’ and ‘‘CO’’) from the Westerschelde estuary (the Netherlands) (Fig. 1), the EmsDollard estuary on the Dutch-German border, and the Colne estuary (Es ...
... Sampling sites and clonal cultures. In addition to the 11 N. phyllepta strains used by Créach et al. (2006) (strain designations beginning with ‘‘CCY’’ and ‘‘CO’’) from the Westerschelde estuary (the Netherlands) (Fig. 1), the EmsDollard estuary on the Dutch-German border, and the Colne estuary (Es ...
Roles of parasites in animal invasions
... natives [26]. Empirical support for this hypothesis comes from observations across a range of taxa, which confirm that invader populations harbour significantly fewer parasites than do native populations [12,24,25]. Although potential mechanisms leading to such patterns are regularly proposed, such ...
... natives [26]. Empirical support for this hypothesis comes from observations across a range of taxa, which confirm that invader populations harbour significantly fewer parasites than do native populations [12,24,25]. Although potential mechanisms leading to such patterns are regularly proposed, such ...
Constraints and tradeoffs: toward a predictive theory of competition and succession
... Huston and Smith 1987), or of the maintenance of genetic diversity within a population (e.g., Slatkin 1978, Gillespie 1984). The only alternative to constraints and tradeoffs is neutrality, with organisms or genes assumed to be functionally identical or neutral (e.g., Kimura 1983), and with diversit ...
... Huston and Smith 1987), or of the maintenance of genetic diversity within a population (e.g., Slatkin 1978, Gillespie 1984). The only alternative to constraints and tradeoffs is neutrality, with organisms or genes assumed to be functionally identical or neutral (e.g., Kimura 1983), and with diversit ...
Appendix
... Main findings: 41 observers with different experience levels recorded presence/absence data within a limited list of only 6 species or species guilds, and their results compared with a reference survey. Standard deviations of surveyor differences relative to actual frequency ranged from 5% (more com ...
... Main findings: 41 observers with different experience levels recorded presence/absence data within a limited list of only 6 species or species guilds, and their results compared with a reference survey. Standard deviations of surveyor differences relative to actual frequency ranged from 5% (more com ...
Nevada Wildlife Action Plan - Nevada Department of Wildlife
... The Nevada Natural Heritage Program recognizes 136 species of mammals that occur or historically occurred in Nevada. Of those species, American bison, gray wolf, North American lynx, Arizona cotton rat, and grizzly bear are considered to be extirpated (i.e., they no longer occur) in Nevada. Of these ...
... The Nevada Natural Heritage Program recognizes 136 species of mammals that occur or historically occurred in Nevada. Of those species, American bison, gray wolf, North American lynx, Arizona cotton rat, and grizzly bear are considered to be extirpated (i.e., they no longer occur) in Nevada. Of these ...
The Effects of Burmese Pythons on Everglades Ecosystems
... which were subsequently released nearby), only three Burmese pythons were caught (Reed et al. 2011). There were other factors that may have interfered with the number of captured snakes such as the large numbers of prey species in the area to begin with as well as the python’s tendency to be ambush ...
... which were subsequently released nearby), only three Burmese pythons were caught (Reed et al. 2011). There were other factors that may have interfered with the number of captured snakes such as the large numbers of prey species in the area to begin with as well as the python’s tendency to be ambush ...
2001japplecol
... distribution had persistent seed banks, although this was less likely to be the case for exotics than natives. Biological factors causing mortality of buried seeds in natural communities are incompletely understood, although they are known to include a wide range of vertebrate and invertebrate seed ...
... distribution had persistent seed banks, although this was less likely to be the case for exotics than natives. Biological factors causing mortality of buried seeds in natural communities are incompletely understood, although they are known to include a wide range of vertebrate and invertebrate seed ...
Raport privind informa*iile colectate pentru speciile de
... The poaching of wolves has decreased to less than 10 documented cases per year, most poaching acts were using guns and poison (Kaczensky et al., 2012a). There is no information about the real dimension of the poaching activity but seems to be significantly larger than the official information. Offic ...
... The poaching of wolves has decreased to less than 10 documented cases per year, most poaching acts were using guns and poison (Kaczensky et al., 2012a). There is no information about the real dimension of the poaching activity but seems to be significantly larger than the official information. Offic ...
Peterson et al. 2013
... Each species was treated as a “target” in three treatments: alone, with M. guttatus, and with M. laciniatus. We planted three to four seeds (randomly thinned to one plant) from the “target” species seed pool into the center of 38 mm by 38 mm by 57 mm pots, and for neighbor treatments, we planted fou ...
... Each species was treated as a “target” in three treatments: alone, with M. guttatus, and with M. laciniatus. We planted three to four seeds (randomly thinned to one plant) from the “target” species seed pool into the center of 38 mm by 38 mm by 57 mm pots, and for neighbor treatments, we planted fou ...
General impacts of the feral pig (Sus scrofa) Rooting by pigs disturbs
... Rooting by pigs disturbs the seed bank, reduces surface vegetation and alters the soil by increasing soil temperature, increasing or decreasing the nitrogen content, increasing oxidation and increasing the leaching of Ca, P, Zn, Cu and Mg (Kotanen 1994, Singer Swank and Clebsch 1984, Arrington, Toth ...
... Rooting by pigs disturbs the seed bank, reduces surface vegetation and alters the soil by increasing soil temperature, increasing or decreasing the nitrogen content, increasing oxidation and increasing the leaching of Ca, P, Zn, Cu and Mg (Kotanen 1994, Singer Swank and Clebsch 1984, Arrington, Toth ...
Elucidating the native sources of an invasive tree species, Acacia
... framework for testing hypotheses about the processes driving biological invasions, such as introduction histories, hybridization, gene diversity and, ultimately, evolutionary potential (Stepien et al., 2002). Relating historical biogeography to contemporary patterns of gene diversity associated with ...
... framework for testing hypotheses about the processes driving biological invasions, such as introduction histories, hybridization, gene diversity and, ultimately, evolutionary potential (Stepien et al., 2002). Relating historical biogeography to contemporary patterns of gene diversity associated with ...
Introduced species
![](https://commons.wikimedia.org/wiki/Special:FilePath/Melilotus_alba_bgiu.jpg?width=300)
An introduced, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its native distributional range, which has arrived there by human activity, either deliberate or accidental. Non-native species can have various effects on the local ecosystem. Introduced species that become established and spread beyond the place of introduction are called invasive species. Some have a negative effect on a local ecosystem. Some introduced species may have no negative effect or only minor impact. Some species have been introduced intentionally to combat pests. They are called biocontrols and may be regarded as beneficial as an alternative to pesticides in agriculture for example. In some instances the potential for being beneficial or detrimental in the long run remains unknown. A list of some introduced species is given in a separate article.The effects of introduced species on natural environments have gained much scrutiny from scientists, governments, farmers and others.