Current Normative Concepts in Conservation
... it is now home to 23 (Moyle 1989). Thus its fish fauna is nearly twice as diverse as in its historic condition. The cultural introduction of 16 species has made Clear Lake a more diverse aquatic community than it formerly was, but it is now similar to many other aquatic communities and 5 of its nati ...
... it is now home to 23 (Moyle 1989). Thus its fish fauna is nearly twice as diverse as in its historic condition. The cultural introduction of 16 species has made Clear Lake a more diverse aquatic community than it formerly was, but it is now similar to many other aquatic communities and 5 of its nati ...
The mangrove swamp
... and special seeds to colonise mud flats. Their roots have extensions called pneumatophores which grow upwards out of the salty, anaerobic mud to reach the air the plant requires. The tangle of roots in the mangrove swamp traps decaying plant and animal matter and helps make the waters of the mangrov ...
... and special seeds to colonise mud flats. Their roots have extensions called pneumatophores which grow upwards out of the salty, anaerobic mud to reach the air the plant requires. The tangle of roots in the mangrove swamp traps decaying plant and animal matter and helps make the waters of the mangrov ...
Limiting resources and the regulation of diversity in phytoplankton
... the relationship between phytoplankton diversity and limiting resources (N, P, Si, and light) over two summers in three lakes in the Yellowstone (Wyoming, USA) region. Diversity was highly variable along temporal and spatial axes within lakes. We discovered a strong positive correlation between dive ...
... the relationship between phytoplankton diversity and limiting resources (N, P, Si, and light) over two summers in three lakes in the Yellowstone (Wyoming, USA) region. Diversity was highly variable along temporal and spatial axes within lakes. We discovered a strong positive correlation between dive ...
Multispecies advice
... Figure 8.3.3.2 presents the main results of the SMS model updated and reviewed at the ICES Workshop on Baltic Multispecies (WKMULTBAL) in 2012 (ICES, 2012a) and presented in WKBALT in 2013 with updates of data from the benchmark. For more specific model settings please look at WKBALT 2013 (ICES, 201 ...
... Figure 8.3.3.2 presents the main results of the SMS model updated and reviewed at the ICES Workshop on Baltic Multispecies (WKMULTBAL) in 2012 (ICES, 2012a) and presented in WKBALT in 2013 with updates of data from the benchmark. For more specific model settings please look at WKBALT 2013 (ICES, 201 ...
Spatio-temporal water uptake patterns of tree saplings are not
... spatial and temporal uptake of different nutrients and water, stable isotopes have become a powerful tool as they allow tracing of the flow of elements in biological systems (Adams and Grierson, 2001). In particular, stable isotopes allow the direct testing of resource partitioning, while considerin ...
... spatial and temporal uptake of different nutrients and water, stable isotopes have become a powerful tool as they allow tracing of the flow of elements in biological systems (Adams and Grierson, 2001). In particular, stable isotopes allow the direct testing of resource partitioning, while considerin ...
controls on food webs in gravel-bedded rivers
... odd numbers of trophic levels, e.g. plants alone, or predators protecting plants from herbivores) or “barren” (chains with even numbers, with grazers as top consumers, or with grazers protected by predators of predators) (Fretwell, 1977, Oksanen et al., 1981). “Bottom up” or “energy flow” food chain ...
... odd numbers of trophic levels, e.g. plants alone, or predators protecting plants from herbivores) or “barren” (chains with even numbers, with grazers as top consumers, or with grazers protected by predators of predators) (Fretwell, 1977, Oksanen et al., 1981). “Bottom up” or “energy flow” food chain ...
pdf. - Robert Colwell
... parasites under captive rearing. In a growing number of cases, when the last individuals of rare species are brought into captivity for breeding with the aim of subsequent reintroduction of the species, they are immediately treated with biocides (pesticides, endectocides, or antihelminthics) to elim ...
... parasites under captive rearing. In a growing number of cases, when the last individuals of rare species are brought into captivity for breeding with the aim of subsequent reintroduction of the species, they are immediately treated with biocides (pesticides, endectocides, or antihelminthics) to elim ...
Interspecific Competition in Plants: How Well Do Current Methods
... review these in detail. For a more comprehensive analysis of the classes of questions asked in interspecific plant competition research, see other recent reviews by Connell (1983), Schoener (1983), Keddy (1989), Goldberg and Barton (1992), Goldberg and Scheiner (1993), and Cousens (1996). We limit o ...
... review these in detail. For a more comprehensive analysis of the classes of questions asked in interspecific plant competition research, see other recent reviews by Connell (1983), Schoener (1983), Keddy (1989), Goldberg and Barton (1992), Goldberg and Scheiner (1993), and Cousens (1996). We limit o ...
File - The Eurasian Ruffe
... neuromasts. Neuromasts are organs that allow organisms to exceptionally feel vibrations in the water. This allows the Ruffe to dodge predators and find prey better than other fish. Even worse, the neuromasts in the Eurasian Ruffe advance over time, while other species’ decline over time. This allows ...
... neuromasts. Neuromasts are organs that allow organisms to exceptionally feel vibrations in the water. This allows the Ruffe to dodge predators and find prey better than other fish. Even worse, the neuromasts in the Eurasian Ruffe advance over time, while other species’ decline over time. This allows ...
ATTENUATION OF TOP-DOWN AND BOTTOM-UP FORCES IN A COMPLEX TERRESTRIAL COMMUNITY D
... strong and pervasive, but few studies have investigated their interactive effects in speciesrich terrestrial ecosystems. This study focused on arthropods associated with the dominant tree species, Metrosideros polymorpha (Myrtaceae), in Hawaiian forests. Severe soil nutrient limitation on a 120-yr-o ...
... strong and pervasive, but few studies have investigated their interactive effects in speciesrich terrestrial ecosystems. This study focused on arthropods associated with the dominant tree species, Metrosideros polymorpha (Myrtaceae), in Hawaiian forests. Severe soil nutrient limitation on a 120-yr-o ...
Using constraint lines to characterize plant
... plants will grow in size until resources become limiting (see Fig. 2). At this point the thinning line is reached and competition for resources begins. Further increase in size Log (density m-2) is only possible if some plants die. Others will then Fig. 2. A graphical representation of the allometri ...
... plants will grow in size until resources become limiting (see Fig. 2). At this point the thinning line is reached and competition for resources begins. Further increase in size Log (density m-2) is only possible if some plants die. Others will then Fig. 2. A graphical representation of the allometri ...
effects of top predator species on direct
... experiments to compare the direct and indirect effects of three top-predator species, belonging to the same hunting spider guild, on the same species of grasshopper and on oldfield grasses and herbs. Observations under field conditions revealed that each spider species exhibited different hunting be ...
... experiments to compare the direct and indirect effects of three top-predator species, belonging to the same hunting spider guild, on the same species of grasshopper and on oldfield grasses and herbs. Observations under field conditions revealed that each spider species exhibited different hunting be ...
Extinction thresholds: insights from simple models
... Extinction has played a major role in the organization of life on Earth. Almost all species which have existed at some point have already gone extinct. This unavoidable outcome, however, has been aggravated in the last few centuries due to human activity. Since 1600, the extinction of more than 485 ...
... Extinction has played a major role in the organization of life on Earth. Almost all species which have existed at some point have already gone extinct. This unavoidable outcome, however, has been aggravated in the last few centuries due to human activity. Since 1600, the extinction of more than 485 ...
H1110 Sandbanks which are slightly covered by sea water all the time
... ‘Sandbanks which are slightly covered by sea water all the time’ occur widely on the Atlantic coasts of north-west Europe and around the UK coast. They are widespread in inshore waters (within 12 nautical miles of the coast) and also occur offshore in the southern North Sea and in the Irish Sea (bet ...
... ‘Sandbanks which are slightly covered by sea water all the time’ occur widely on the Atlantic coasts of north-west Europe and around the UK coast. They are widespread in inshore waters (within 12 nautical miles of the coast) and also occur offshore in the southern North Sea and in the Irish Sea (bet ...
Global biodiversity patterns of marine phytoplankton and zooplankton
... Atlantic Ocean. For all areas, data were collected on the species composition of nanophytoplankton (2–20 mm), microphytoplankton (20–200 mm), and microzooplankton (20–200 mm; heterotrophic dinoflagellates and ciliates). We call this our ‘global data set’. For one of the Atlantic meridional transects ...
... Atlantic Ocean. For all areas, data were collected on the species composition of nanophytoplankton (2–20 mm), microphytoplankton (20–200 mm), and microzooplankton (20–200 mm; heterotrophic dinoflagellates and ciliates). We call this our ‘global data set’. For one of the Atlantic meridional transects ...
Distinguishing between direct and indirect effects of predators in
... Changes in consumer abundance or behaviour can also alter competitive interactions among species at different trophic levels for other shared resources such as space (Benedetti-Cecchi 2000). The direct and indirect (cascading) effects of loss of predators on lower trophic levels are complex (Wootton ...
... Changes in consumer abundance or behaviour can also alter competitive interactions among species at different trophic levels for other shared resources such as space (Benedetti-Cecchi 2000). The direct and indirect (cascading) effects of loss of predators on lower trophic levels are complex (Wootton ...
pdf
... Killer whales dig deep for dinner have limited exchange with other seamounts. This makes these fish communities very vulnerable to overfishing and the problem is even more pronounced in seamounts located in international waters where effective management strategies and agreements are frequently abse ...
... Killer whales dig deep for dinner have limited exchange with other seamounts. This makes these fish communities very vulnerable to overfishing and the problem is even more pronounced in seamounts located in international waters where effective management strategies and agreements are frequently abse ...
Louisiana Alligator Management Program
... issued based on the population estimates derived from nest counts. Furthermore, information such as landowner, hunter or farmer, length, and shipper are recorded for every wild alligator harvested in compliance with state and federal rules for crocodilian management. Export of alligator skins and pr ...
... issued based on the population estimates derived from nest counts. Furthermore, information such as landowner, hunter or farmer, length, and shipper are recorded for every wild alligator harvested in compliance with state and federal rules for crocodilian management. Export of alligator skins and pr ...
population density
... a given time. What is that resources may be depleted or community may have changed due to arrival of a new predator Continue ...
... a given time. What is that resources may be depleted or community may have changed due to arrival of a new predator Continue ...
The diversity–stability debate
... than that of richer ones; that is, more subject to destructive oscillations in populations, and more vulnerable to invasions”. In fact, both Odum7 and Elton8 arrived at similar conclusions based on the repeated observation that greatly simplified terrestrial communities are characterized by more vio ...
... than that of richer ones; that is, more subject to destructive oscillations in populations, and more vulnerable to invasions”. In fact, both Odum7 and Elton8 arrived at similar conclusions based on the repeated observation that greatly simplified terrestrial communities are characterized by more vio ...
midwest furbearer group
... now established in parts of the Midwest, 2) transient males have been found with increasing regularity, and 3) suitable habitat occurs in most, if not all states. Biologists recommended the following actions regarding management of cougars in the Midwest: 1) manage cougars at appropriate spatial sca ...
... now established in parts of the Midwest, 2) transient males have been found with increasing regularity, and 3) suitable habitat occurs in most, if not all states. Biologists recommended the following actions regarding management of cougars in the Midwest: 1) manage cougars at appropriate spatial sca ...
Benthic use of phytoplankton blooms: Agnes M. L. Karlson
... and (iii) the selection or dominance effect. The niche is often represented as an n-dimensional space, consisting of environmental conditions, resource levels and densities of other organisms, together allowing for the survival, growth and reproduction of species (Hutchinson 1957 in Leibold 1995). I ...
... and (iii) the selection or dominance effect. The niche is often represented as an n-dimensional space, consisting of environmental conditions, resource levels and densities of other organisms, together allowing for the survival, growth and reproduction of species (Hutchinson 1957 in Leibold 1995). I ...
Biodiversity effects on ecosystem functioning: emerging issues and
... propose expanding the range of diversity facets that should be considered for manipulation in experimental studies (Table 1). Species richness is an important and readily quantified component of biodiversity. However, mechanisms by which diversity may influence ecosystem functioning are related more ...
... propose expanding the range of diversity facets that should be considered for manipulation in experimental studies (Table 1). Species richness is an important and readily quantified component of biodiversity. However, mechanisms by which diversity may influence ecosystem functioning are related more ...
report - Oceana
... dugong populations nationally have been in decline and this animal is now believed to be one of the most critically endangered mammals in the Philippines. The dugong is the only living species in the dugong family since the only other member, Stellar’s sea cow, has been extinct since the mid-1700s. ...
... dugong populations nationally have been in decline and this animal is now believed to be one of the most critically endangered mammals in the Philippines. The dugong is the only living species in the dugong family since the only other member, Stellar’s sea cow, has been extinct since the mid-1700s. ...
Overexploitation
Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Sustained overexploitation can lead to the destruction of the resource. The term applies to natural resources such as: wild medicinal plants, grazing pastures, game animals, fish stocks, forests, and water aquifers.In ecology, overexploitation describes one of the five main activities threatening global biodiversity. Ecologists use the term to describe populations that are harvested at a rate that is unsustainable, given their natural rates of mortality and capacities for reproduction. This can result in extinction at the population level and even extinction of whole species. In conservation biology the term is usually used in the context of human economic activity that involves the taking of biological resources, or organisms, in larger numbers than their populations can withstand. The term is also used and defined somewhat differently in fisheries, hydrology and natural resource management.Overexploitation can lead to resource destruction, including extinctions. However it is also possible for overexploitation to be sustainable, as discussed below in the section on fisheries. In the context of fishing, the term overfishing can be used instead of overexploitation, as can overgrazing in stock management, overlogging in forest management, overdrafting in aquifer management, and endangered species in species monitoring. Overexploitation is not an activity limited to humans. Introduced predators and herbivores, for example, can overexploit native flora and fauna.