The Informational Proceeding to Develop Flow Criteria for the Delta Ecosystem
... Importantly, the BDCP is considering flow in relation to the many stressors impacting the Delta ecosystem. For example, the BDCP will highlight the need to address through study and action the effects of ammonia/um concentrations, aquatic habitat losses, food web declines, predators, invasive specie ...
... Importantly, the BDCP is considering flow in relation to the many stressors impacting the Delta ecosystem. For example, the BDCP will highlight the need to address through study and action the effects of ammonia/um concentrations, aquatic habitat losses, food web declines, predators, invasive specie ...
Species extinctions in food webs – local and regional processes Anna Eklöf
... Loss of biodiversity is one of the most severe threats to the ecosystems of the world. The major causes behind the high population and species extinction rates are anthropogenic activities such as overharvesting of natural populations, pollution, climate change and destruction and fragmentation of n ...
... Loss of biodiversity is one of the most severe threats to the ecosystems of the world. The major causes behind the high population and species extinction rates are anthropogenic activities such as overharvesting of natural populations, pollution, climate change and destruction and fragmentation of n ...
Linking nutrient loading, local abiotic variables, richness and
... Abstract. We studied relationships between nutrient loading, local abiotic variables, richness and biomasses of macrophytes, and associated invertebrate species in the north-eastern Baltic Sea. The study showed that nutrient load strongly correlated to the richness and biomass of macroalgal and inve ...
... Abstract. We studied relationships between nutrient loading, local abiotic variables, richness and biomasses of macrophytes, and associated invertebrate species in the north-eastern Baltic Sea. The study showed that nutrient load strongly correlated to the richness and biomass of macroalgal and inve ...
File - Mr. Greening`s Science
... increased. B) The dodo bird population increased after the birds learned to build their nests in trees. C) Human exploitation and introduced species significantly reduced dodo bird populations. D) The dodo bird population became smaller because they preyed upon the introduced species. 20. Rabbits ar ...
... increased. B) The dodo bird population increased after the birds learned to build their nests in trees. C) Human exploitation and introduced species significantly reduced dodo bird populations. D) The dodo bird population became smaller because they preyed upon the introduced species. 20. Rabbits ar ...
The landscape context of trophic interactions: insect spillover across
... (Thomas et al. 2001). In contrast, “cultural species” have a preference for crops and occur only sparsely in non-crop habitats. Examples of cultural species are ground beetles of the genus Pterostichus that occur in crops during the growing season and may hibernate in field margins or in fields with w ...
... (Thomas et al. 2001). In contrast, “cultural species” have a preference for crops and occur only sparsely in non-crop habitats. Examples of cultural species are ground beetles of the genus Pterostichus that occur in crops during the growing season and may hibernate in field margins or in fields with w ...
On the different nature of top-down and bottom
... predation has been successfully developed to tackle the problem of the relative importance of top-down and bottom-up impacts for animal behaviour, especially in fish and zooplankton (Mangel & Clark, 1988). However, the common currency of fitness has not solved the problem that the nature of top-down ...
... predation has been successfully developed to tackle the problem of the relative importance of top-down and bottom-up impacts for animal behaviour, especially in fish and zooplankton (Mangel & Clark, 1988). However, the common currency of fitness has not solved the problem that the nature of top-down ...
Assessment of Coastal Fish in the Baltic Sea
... important factors include seabed type for bottomdwelling fish, and algal and seagrass conditions in shallow waters for near-coastal species. Monitoring of coastal fish using multi-mesh gillnets and gillnet series has been carried out in fifteen areas in the Baltic Sea. The objectives of this monitor ...
... important factors include seabed type for bottomdwelling fish, and algal and seagrass conditions in shallow waters for near-coastal species. Monitoring of coastal fish using multi-mesh gillnets and gillnet series has been carried out in fifteen areas in the Baltic Sea. The objectives of this monitor ...
What controls who is where in freshwater fish communities — the
... temporal scales involved may be important given that variability in species composition and environmental conditions may have different scales (Ross et al. 1985). Finally, the resolution or scale of the data used in such analyses may also influence our conclusions. Rahel (1990) showed that differenc ...
... temporal scales involved may be important given that variability in species composition and environmental conditions may have different scales (Ross et al. 1985). Finally, the resolution or scale of the data used in such analyses may also influence our conclusions. Rahel (1990) showed that differenc ...
DRAFT BA Y-DELTA OVERSIGHT
... almost impossible to define management actions that will result in specific changes in populations of target species and that deliberations regarding these actions should recognize that they may not achieve their intended objectives because of this instability. In addition, he believes federal and s ...
... almost impossible to define management actions that will result in specific changes in populations of target species and that deliberations regarding these actions should recognize that they may not achieve their intended objectives because of this instability. In addition, he believes federal and s ...
Cascading top-down effects of changing oceanic predator
... webs resulting in inverse patterns in abundance across two or more trophic links (Pace et al. 1999). Although trophic cascades may be present in stationary food webs, their effects are often seen most clearly after a perturbation. For example, sea otter (Enhydra lutris) overexploitation in Alaska le ...
... webs resulting in inverse patterns in abundance across two or more trophic links (Pace et al. 1999). Although trophic cascades may be present in stationary food webs, their effects are often seen most clearly after a perturbation. For example, sea otter (Enhydra lutris) overexploitation in Alaska le ...
Trophic network models explain instability of Early Triassic terrestrial
... marine ecosystems (Looy et al. 1999; Pruss & Bottjer 2004). We investigated the potential role of community structure in this event using a numerical network simulation model (cascading extinction on graphs, CEG) to examine the extent to which food-web topology promotes or inhibits the propagation o ...
... marine ecosystems (Looy et al. 1999; Pruss & Bottjer 2004). We investigated the potential role of community structure in this event using a numerical network simulation model (cascading extinction on graphs, CEG) to examine the extent to which food-web topology promotes or inhibits the propagation o ...
- Wiley Online Library
... webs resulting in inverse patterns in abundance across two or more trophic links (Pace et al. 1999). Although trophic cascades may be present in stationary food webs, their effects are often seen most clearly after a perturbation. For example, sea otter (Enhydra lutris) overexploitation in Alaska le ...
... webs resulting in inverse patterns in abundance across two or more trophic links (Pace et al. 1999). Although trophic cascades may be present in stationary food webs, their effects are often seen most clearly after a perturbation. For example, sea otter (Enhydra lutris) overexploitation in Alaska le ...
Biodiversity and ecosystem stability: a synthesis of underlying
... There is mounting evidence that biodiversity increases the stability of ecosystem processes in changing environments, but the mechanisms that underlie this effect are still controversial and poorly understood. Here, we extend mechanistic theory of ecosystem stability in competitive communities to cl ...
... There is mounting evidence that biodiversity increases the stability of ecosystem processes in changing environments, but the mechanisms that underlie this effect are still controversial and poorly understood. Here, we extend mechanistic theory of ecosystem stability in competitive communities to cl ...
PowerPoint presentation (PPT file)
... The Sustainable Wetlands Adaptation and Mitigation Program (SWAMP) is a collaborative effort by CIFOR, the USDA Forest Service, and the Oregon State University with support from USAID. How to cite this file MacKenzie R and Warren M. 2015. Wetlands and ecosystem services [PowerPoint presentation]. In ...
... The Sustainable Wetlands Adaptation and Mitigation Program (SWAMP) is a collaborative effort by CIFOR, the USDA Forest Service, and the Oregon State University with support from USAID. How to cite this file MacKenzie R and Warren M. 2015. Wetlands and ecosystem services [PowerPoint presentation]. In ...
Threats to Biodiversity - Wildlife Ecology and Conservation
... humans have had enormous impacts on the form and diversity of ecosystems. Ultimately, we have set in motion the sixth great mass extinction event in the history of the Earth—and the only one caused by a living species. Human population and consumption pressures are the root threat to biodiversity (s ...
... humans have had enormous impacts on the form and diversity of ecosystems. Ultimately, we have set in motion the sixth great mass extinction event in the history of the Earth—and the only one caused by a living species. Human population and consumption pressures are the root threat to biodiversity (s ...
The Role of Consumers in Community Diversity
... 3. Consumers can determine the distribution of biomass among trophic groups; 4. Stability and reliability of systems & populations is affected by trophic structure as well as numbers of species within trophic groups; 5. Interactions may exist between diversity at one level and diversity at another. ...
... 3. Consumers can determine the distribution of biomass among trophic groups; 4. Stability and reliability of systems & populations is affected by trophic structure as well as numbers of species within trophic groups; 5. Interactions may exist between diversity at one level and diversity at another. ...
IMPACT: Toward a framework for understanding the
... we review some of the best examples of studies, both experimental and observational, that have quantified impacts. The impact of an invader can be measured at five levels: (1) effects on individuals (including demographic rates such as mortality and growth), (2) genetic effects (including hybridizat ...
... we review some of the best examples of studies, both experimental and observational, that have quantified impacts. The impact of an invader can be measured at five levels: (1) effects on individuals (including demographic rates such as mortality and growth), (2) genetic effects (including hybridizat ...
Interspecific competition in metapopulations
... extinction propensities leading to different pre-competitive thresholds. P2. As the number of competing species increases, each species should occupy a decreasing proportion of the patches (e.g. Slatkin, 1974; Hanski, 1983; Hanski & Ranta, 1983). P3. Species with similar or identical colonization an ...
... extinction propensities leading to different pre-competitive thresholds. P2. As the number of competing species increases, each species should occupy a decreasing proportion of the patches (e.g. Slatkin, 1974; Hanski, 1983; Hanski & Ranta, 1983). P3. Species with similar or identical colonization an ...
Reciprocal trophic niche shifts in native and invasive fish: salmonids
... example, TH increases with body size in many fish species, because larger individuals can consume prey over a wider size range (e.g. Werner & Gilliam, 1984; Hjelm et al., 2001; Post, 2003). In addition, PL should increase with body size in Galaxias platei that change from planktonic to littoral habi ...
... example, TH increases with body size in many fish species, because larger individuals can consume prey over a wider size range (e.g. Werner & Gilliam, 1984; Hjelm et al., 2001; Post, 2003). In addition, PL should increase with body size in Galaxias platei that change from planktonic to littoral habi ...
The Galapagos Sailfin Grouper
... the west coast of Central America, as well as with tropical species from the Indo-Pacific. These waters are also home to an impressive number of endemic marine fishes, including the distinctive Galapagos sailfin grouper, or as it is locally known, the bacalao (Constant, 1992). The Galapagos sailfin ...
... the west coast of Central America, as well as with tropical species from the Indo-Pacific. These waters are also home to an impressive number of endemic marine fishes, including the distinctive Galapagos sailfin grouper, or as it is locally known, the bacalao (Constant, 1992). The Galapagos sailfin ...
Feeding on survival-food: gelatinous plankton as
... transfer in marine trophic webs, principally because these animals are usually damaged beyond recognition when sampled with conventional plankton nets. As a consequence, their distribution and abundance patterns are poorly known. Furthermore, even though many papers have focused on their role as con ...
... transfer in marine trophic webs, principally because these animals are usually damaged beyond recognition when sampled with conventional plankton nets. As a consequence, their distribution and abundance patterns are poorly known. Furthermore, even though many papers have focused on their role as con ...
LIST OF ABSTRACTS - Wisconsin AFS > Home
... Abstract: Cisco (Coregonus artedi) are important prey for several economicallyimportant sportfish species, particularly lake trout (Salvelinus namaycush), muskellunge (Esox masquinongy) and walleye (Sander vitreus). Unfortunately, cisco appear to be declining in parts of the Midwest. Wisconsin has 1 ...
... Abstract: Cisco (Coregonus artedi) are important prey for several economicallyimportant sportfish species, particularly lake trout (Salvelinus namaycush), muskellunge (Esox masquinongy) and walleye (Sander vitreus). Unfortunately, cisco appear to be declining in parts of the Midwest. Wisconsin has 1 ...
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.