Direct and indirect community effects of rebuilding plans
... classes is due to increased predation pressure from the adults of the target species (Figure 5b), whereas the larger asymptotic size classes are also affected by increased predation pressure during their juvenile stages. Furthermore, when the individuals of the larger asymptotic size classes are in ...
... classes is due to increased predation pressure from the adults of the target species (Figure 5b), whereas the larger asymptotic size classes are also affected by increased predation pressure during their juvenile stages. Furthermore, when the individuals of the larger asymptotic size classes are in ...
Duck Season 2016 - Birdlife Australia
... particularly threatened species such as bitterns, Australian Painted Snipe and Brolga. The historic and ongoing decline, degradation and fragmentation of wetlands in Victoria and predicted increase in the frequency and severity of drought, places threatened species at an increased risk of extinction ...
... particularly threatened species such as bitterns, Australian Painted Snipe and Brolga. The historic and ongoing decline, degradation and fragmentation of wetlands in Victoria and predicted increase in the frequency and severity of drought, places threatened species at an increased risk of extinction ...
Fluctuating resources in plant communities: a general theory of invasibility FORUM
... emphasized the importance of a variable environment in permitting exotic species to invade speciesrich communities. Johnstone (1986) proposed that `invasion is caused by the removal of a barrier that has previously excluded a plant species.' In reviewing tree invasion into old ®elds, Myster (1993) e ...
... emphasized the importance of a variable environment in permitting exotic species to invade speciesrich communities. Johnstone (1986) proposed that `invasion is caused by the removal of a barrier that has previously excluded a plant species.' In reviewing tree invasion into old ®elds, Myster (1993) e ...
The Extinction Crisis
... Patterns of Extinction – Reasons for differences in extinction rate (cont.) • Island species may have evolved in the absence of terrestrial predators – Characteristics contributing to extinction ...
... Patterns of Extinction – Reasons for differences in extinction rate (cont.) • Island species may have evolved in the absence of terrestrial predators – Characteristics contributing to extinction ...
marine ecosystems and fisheries
... are harvested from the sea. Fish, crustaceans, and mollusks are caught for food, fertilizer, and many other products. Despite the vastness of the ocean, it is not limitless. Ocean resources are under intense pressure to satisfy expanding demands caused by population growth and globalization. Many va ...
... are harvested from the sea. Fish, crustaceans, and mollusks are caught for food, fertilizer, and many other products. Despite the vastness of the ocean, it is not limitless. Ocean resources are under intense pressure to satisfy expanding demands caused by population growth and globalization. Many va ...
Ch.14-Lesson-2-WSs-f..
... 1. Possible answer: Plant populations might compete for space and light. Other populations eat the plants. 2. Possible answer: Insects might eat the plants or other populations of insects. They are eaten by fish, ducks, turtles, and other populations. 3. Possible answer: Different populations of fis ...
... 1. Possible answer: Plant populations might compete for space and light. Other populations eat the plants. 2. Possible answer: Insects might eat the plants or other populations of insects. They are eaten by fish, ducks, turtles, and other populations. 3. Possible answer: Different populations of fis ...
Ecological and evolutionary consequences of size
... Introduction Body size is generally considered to be one of the most important traits of an organism because it correlates with many aspects of its biology, from life history to ecology (Peters 1983; Calder 1984). Size-selective harvesting, where large individuals of a particular species are prefere ...
... Introduction Body size is generally considered to be one of the most important traits of an organism because it correlates with many aspects of its biology, from life history to ecology (Peters 1983; Calder 1984). Size-selective harvesting, where large individuals of a particular species are prefere ...
The importance of large carnivores to healthy ecosystems
... As productivity increases so does plant biomass, until there is enough productivity to support a second trophic level, the herbivorous consumers. With two trophic levels, herbivore biomass increases with increasing productivity, but their grazing activity limits plant biomass until productivity incr ...
... As productivity increases so does plant biomass, until there is enough productivity to support a second trophic level, the herbivorous consumers. With two trophic levels, herbivore biomass increases with increasing productivity, but their grazing activity limits plant biomass until productivity incr ...
Rabbit and Rodent Management in Alberta
... that had been removed. Today, the beaver is common throughout most of Canada, and has returned to the list of most valuable furbearers. Unfortunately, this increase in numbers has caused the beaver to become a pest in many regions. Beavers plug culverts and otherwise dam streams that cause flooding ...
... that had been removed. Today, the beaver is common throughout most of Canada, and has returned to the list of most valuable furbearers. Unfortunately, this increase in numbers has caused the beaver to become a pest in many regions. Beavers plug culverts and otherwise dam streams that cause flooding ...
MillerLevine4_2_Rev1_Notes - Bloomsburg Area School District
... Sometimes changes in the population of a single species, often called a___________________, can cause dramatic changes in the structure of a community. In the cold waters off the Pacific coast of North America, for example, ______________ devour large quantities of _________________. Urchins a ...
... Sometimes changes in the population of a single species, often called a___________________, can cause dramatic changes in the structure of a community. In the cold waters off the Pacific coast of North America, for example, ______________ devour large quantities of _________________. Urchins a ...
Mutualisms - Biology Courses Server
... commensalisms or antagonistic interactions (predator-prey, host-parasite, competition). • Mutualism between species is favored when there are repeated interactions and when cooperation is conditional on the other partner’s behavior or when interactions occur over a small spatial scale. • Mutualism ...
... commensalisms or antagonistic interactions (predator-prey, host-parasite, competition). • Mutualism between species is favored when there are repeated interactions and when cooperation is conditional on the other partner’s behavior or when interactions occur over a small spatial scale. • Mutualism ...
Climate Change in the Baltic Sea region
... of ocean acidification is probably unprecedented in the past 300 million years (Pörtner et al. 2014). Based on current data it has been estimated that the pH will drop from the present level of 8.1 by another 0.5 units, which means that acidification will more than double in the 21st century in the ...
... of ocean acidification is probably unprecedented in the past 300 million years (Pörtner et al. 2014). Based on current data it has been estimated that the pH will drop from the present level of 8.1 by another 0.5 units, which means that acidification will more than double in the 21st century in the ...
A new formulation for determination of the competition coefficient in
... in a given time is a linear function of resource densities. 3. Per capita growth rates of the consumer populations are linear functions of the extent of resources consumed. 4. Homogeneity is assumed for all consumers and resources, resulting in no genetic or size/age-specific variation in the utiliz ...
... in a given time is a linear function of resource densities. 3. Per capita growth rates of the consumer populations are linear functions of the extent of resources consumed. 4. Homogeneity is assumed for all consumers and resources, resulting in no genetic or size/age-specific variation in the utiliz ...
Economic instruments to achieve ecosystem objectives in fisheries
... how system variables respond to exogenous fishing effort changes. These derivatives are contained in the (II) Jacobian matrices e, Ye and Gx. Gx is the biological community matrix as previously discussed. However, these two equations make it clear that the matrices e and Ye - which may be regarde ...
... how system variables respond to exogenous fishing effort changes. These derivatives are contained in the (II) Jacobian matrices e, Ye and Gx. Gx is the biological community matrix as previously discussed. However, these two equations make it clear that the matrices e and Ye - which may be regarde ...
In Retrospect: The book that began invasion ecology
... are likely to contain predators or parasites that can control invaders, whereas simpler food webs are more vulnerable to population explosions. As evidence, he pointed to the disproportionate numbers of invaders in environments such as remote islands and boreal forests, and those on cultivated land ...
... are likely to contain predators or parasites that can control invaders, whereas simpler food webs are more vulnerable to population explosions. As evidence, he pointed to the disproportionate numbers of invaders in environments such as remote islands and boreal forests, and those on cultivated land ...
Managing for Threatened, Endangered, and Sensitive Species
... under the focal conservation targets and should be protected through the management of the broader focal conservation targets. This approach also benefits state listed or common species; thus it enhances biodiversity. For example, at aafb, Eggert’s sunflower was classified as a threatened species pr ...
... under the focal conservation targets and should be protected through the management of the broader focal conservation targets. This approach also benefits state listed or common species; thus it enhances biodiversity. For example, at aafb, Eggert’s sunflower was classified as a threatened species pr ...
Fragmentation
... (In other words, make sure you’re comparing apples to apples.) 5. There may be time-lagged effects (“extinction debt”). Epilogue: There are both natural and anthropogenic factors that generate landscape patterns. Anthropogenic factors are not "modern," for humans have been modifying their environmen ...
... (In other words, make sure you’re comparing apples to apples.) 5. There may be time-lagged effects (“extinction debt”). Epilogue: There are both natural and anthropogenic factors that generate landscape patterns. Anthropogenic factors are not "modern," for humans have been modifying their environmen ...
Ecosystem Integrity - Ecology and Society
... approach to ecosystem management is to recognize that various genetic, competitive, and behavioral processes (rather than states) are responsible for maintaining the key features of observed ecosystems, and that the dynamics of these processes vary with the scale of description. Holling (1992) propo ...
... approach to ecosystem management is to recognize that various genetic, competitive, and behavioral processes (rather than states) are responsible for maintaining the key features of observed ecosystems, and that the dynamics of these processes vary with the scale of description. Holling (1992) propo ...
mangroves - Department of Environmental Science and Policy
... taken into account by the planner • If all values are considered (fish production and storm protection) the resulting optimal fish stock would be lower. ...
... taken into account by the planner • If all values are considered (fish production and storm protection) the resulting optimal fish stock would be lower. ...
A new hypothesis to explain the coexistence of n species in the
... where λ is a parameter representing the inter-species competition. The results are plotted in Figs. 3 and 4, with λ = 0.1 and λ = 0.55 and over periods of 400 and 1000 time units, respectively. This model highlights some competition of each species with the others. From the remark on Proposition 1, ...
... where λ is a parameter representing the inter-species competition. The results are plotted in Figs. 3 and 4, with λ = 0.1 and λ = 0.55 and over periods of 400 and 1000 time units, respectively. This model highlights some competition of each species with the others. From the remark on Proposition 1, ...
Dynamics of Ecosystems
... partly accessible to plants; the lower confined layers are generally out of reach, although they can be “mined” by humans. The water table is recharged by water that percolates through the soil from precipitation as well as by water that seeps downward from ponds, lakes, and streams. The deep aquife ...
... partly accessible to plants; the lower confined layers are generally out of reach, although they can be “mined” by humans. The water table is recharged by water that percolates through the soil from precipitation as well as by water that seeps downward from ponds, lakes, and streams. The deep aquife ...
2010 - The Global Biodiversity Challenge
... Biodiversity is being lost at increasing rates At the genetic level • 75% crop genetic diversity lost in past century At the species level • 20% freshwater fish species are extinct, threatened of endangered in recent decades • 75 % marine fish stocks are depleted, overexploited or at biological lim ...
... Biodiversity is being lost at increasing rates At the genetic level • 75% crop genetic diversity lost in past century At the species level • 20% freshwater fish species are extinct, threatened of endangered in recent decades • 75 % marine fish stocks are depleted, overexploited or at biological lim ...
full ICES overview assessment of non
... species have been identified in OSPAR regions. However, it is likely that this number under represents the total number of species as long-term monitoring and recording data are not available for many species. Also, for some groups of non-indigenous species, taxonomic identification can be difficult ...
... species have been identified in OSPAR regions. However, it is likely that this number under represents the total number of species as long-term monitoring and recording data are not available for many species. Also, for some groups of non-indigenous species, taxonomic identification can be difficult ...
Lake Huron October 1, 2014 to September 30, 2015 Zander vitreus
... Fisheries Research Station (Photo 1); and 2) a gill-net survey conducted since 1989 by the Alpena Fisheries Research Station (Photo 2). The bottom trawl survey collects young-of-year Walleye and Yellow Perch as well as prey fish (including juveniles of other species), while the gill-net survey colle ...
... Fisheries Research Station (Photo 1); and 2) a gill-net survey conducted since 1989 by the Alpena Fisheries Research Station (Photo 2). The bottom trawl survey collects young-of-year Walleye and Yellow Perch as well as prey fish (including juveniles of other species), while the gill-net survey colle ...
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.