Habitat Loss, Trophic Collapse, and the Decline of Ecosystem
... services will initially be slow but will then accelerate as species from higher trophic levels are ...
... services will initially be slow but will then accelerate as species from higher trophic levels are ...
Characterization of topological keystone species Local, global and
... We have recently introduced an index characterizing the importance of a node in a network which fulfills the requirements for being considered a ‘‘meso-scale’’ index of positional importance of trophic groups in a food web. This index is named the ‘‘subgraph centrality’’ of a node because it charact ...
... We have recently introduced an index characterizing the importance of a node in a network which fulfills the requirements for being considered a ‘‘meso-scale’’ index of positional importance of trophic groups in a food web. This index is named the ‘‘subgraph centrality’’ of a node because it charact ...
HOMOGENIZATION OF FRESHWATER FAUNAS Frank J. Rahel
... rehabilitation efforts involving degraded urban water bodies that currently share the same group of nonnative, pollution-tolerant species. As habitat conditions improve, cosmopolitan species such as common carp, goldfish, and bullheads may be replaced by more distinctive species native to the region ...
... rehabilitation efforts involving degraded urban water bodies that currently share the same group of nonnative, pollution-tolerant species. As habitat conditions improve, cosmopolitan species such as common carp, goldfish, and bullheads may be replaced by more distinctive species native to the region ...
The community context of species` borders: ecological and
... populations at elevations at the base of the mountain may adapt to survive there. What prevents a sequence of such episodes of local adaptation from eventually allowing the populations to march across the mountain? One explanation is that there may not be sufficient genetic variation in the populati ...
... populations at elevations at the base of the mountain may adapt to survive there. What prevents a sequence of such episodes of local adaptation from eventually allowing the populations to march across the mountain? One explanation is that there may not be sufficient genetic variation in the populati ...
A pharyngeal jaw evolutionary innovation
... barrier and gain access to new niches (1). They are often framed as “key innovations” that can promote rapid diversification in the groups that evolve them (2, 3), and the search for key innovations has become a major component of modern macroevolutionary studies (4, 5). However, despite the obvious ...
... barrier and gain access to new niches (1). They are often framed as “key innovations” that can promote rapid diversification in the groups that evolve them (2, 3), and the search for key innovations has become a major component of modern macroevolutionary studies (4, 5). However, despite the obvious ...
The University of Chicago Press The American Society of Naturalists
... Tilman 1988, 2004; Chase and Leibold 2003). The tradeoff surface reflects the full range of evolutionarily sustainable interspecific differences in the responses of species to limiting factors. The growth isoclines of species are constrained to being no better than tangent to the interspecific trade ...
... Tilman 1988, 2004; Chase and Leibold 2003). The tradeoff surface reflects the full range of evolutionarily sustainable interspecific differences in the responses of species to limiting factors. The growth isoclines of species are constrained to being no better than tangent to the interspecific trade ...
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 ...
Habitat loss, trophic collapse, and the decline of ecosystem services
... We have used the list of ecosystem goods and services developed by the Millennium Ecosystem Assessment as the basis of our list of services provided by different natural and human-modified ecosystems (Table 1; Millennium Ecosystem Assessment 2003). We have then classified the response of ecosystem ser ...
... We have used the list of ecosystem goods and services developed by the Millennium Ecosystem Assessment as the basis of our list of services provided by different natural and human-modified ecosystems (Table 1; Millennium Ecosystem Assessment 2003). We have then classified the response of ecosystem ser ...
Biodiversity as spatial insurance: the effects of habitat fragmentation
... complete understanding of the spatial processes affecting the relationship between biodiversity and ecosystem functioning at landscape (e.g. more than one ecosystem), regional, or global scales (Gonzalez and Chaneton 2002, Rantalainen et al. 2005, Srivastava and Velland 2005, Dobson et al. 2006). Th ...
... complete understanding of the spatial processes affecting the relationship between biodiversity and ecosystem functioning at landscape (e.g. more than one ecosystem), regional, or global scales (Gonzalez and Chaneton 2002, Rantalainen et al. 2005, Srivastava and Velland 2005, Dobson et al. 2006). Th ...
Speciation - KSU Web Home
... Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings ...
... Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings ...
Estimates of species extinctions from species–area relationships
... assume implicitly that the mechanisms causing species richness to increase or decrease with area are equivalent and independent of the ecological context. This is an important issue that is common to all area-based estimation of species loss and that leads to several limitations. First, coexistence ...
... assume implicitly that the mechanisms causing species richness to increase or decrease with area are equivalent and independent of the ecological context. This is an important issue that is common to all area-based estimation of species loss and that leads to several limitations. First, coexistence ...
BIOGEOGRAPHY 8
... dimension or as a polygon in two dimensions. Null models have been applied to the pattern of species occurrences in one and two dimensions across a spectrum of spatial scales. At small scales, one-dimensional analyses are appropriate for species occurrences along environmental gradients such as moun ...
... dimension or as a polygon in two dimensions. Null models have been applied to the pattern of species occurrences in one and two dimensions across a spectrum of spatial scales. At small scales, one-dimensional analyses are appropriate for species occurrences along environmental gradients such as moun ...
The DNA of coral reef biodiversity: predicting and protecting genetic
... ecological and evolutionary processes like niche partitioning and species diversification that lead to the complex community structure typical of coral reefs and other highly biodiverse ecosystems. In turn, community-level processes no doubt have consequences for genetic diversity within populations ...
... ecological and evolutionary processes like niche partitioning and species diversification that lead to the complex community structure typical of coral reefs and other highly biodiverse ecosystems. In turn, community-level processes no doubt have consequences for genetic diversity within populations ...
biodiversity- global issues
... living organisms whether plants, animals or microorganisms, and includes diversity within species, between species and among ecosystems. It includes all life forms on the earth and is a life support system, which is essential for the normal functioning of ecosystems and the biosphere as a whole. It ...
... living organisms whether plants, animals or microorganisms, and includes diversity within species, between species and among ecosystems. It includes all life forms on the earth and is a life support system, which is essential for the normal functioning of ecosystems and the biosphere as a whole. It ...
Invasion, Competition, and Biodiversity Loss in Urban
... As discussed above, converting wildlands into urban environments involves changes in both bottom-up and topdown population controls. Past environmental conditions may have selected for traits that enable native species to thrive while preventing potential invasive species from establishing populatio ...
... As discussed above, converting wildlands into urban environments involves changes in both bottom-up and topdown population controls. Past environmental conditions may have selected for traits that enable native species to thrive while preventing potential invasive species from establishing populatio ...
this PDF file - Florida Online Journals
... Insect size and coloration are integral parts of life history strategies that are associated with factors such as mobility, longevity, degree of habitat specialization, activity periods, flight patterns, predator avoidance, and feeding strategies. For example, reproductive rate is related to insect ...
... Insect size and coloration are integral parts of life history strategies that are associated with factors such as mobility, longevity, degree of habitat specialization, activity periods, flight patterns, predator avoidance, and feeding strategies. For example, reproductive rate is related to insect ...
habitat loss, trophic collapse, and the decline of ecosystem services
... We have used the list of ecosystem goods and services developed by the Millennium Ecosystem Assessment as the basis of our list of services provided by different natural and human-modified ecosystems (Table 1; Millennium Ecosystem Assessment 2003). We have then classified the response of ecosystem ser ...
... We have used the list of ecosystem goods and services developed by the Millennium Ecosystem Assessment as the basis of our list of services provided by different natural and human-modified ecosystems (Table 1; Millennium Ecosystem Assessment 2003). We have then classified the response of ecosystem ser ...
3 The Role of Top Carnivores in
... predators) as possible. Most of the time is spent in secure places-in burrows or dense thickets, for example, or in naturally protected spots such as steep mountain slopes or ledges (bighorn sheep and mountain goats). If predators are removed, then the quest for security ceases to be the leading reg ...
... predators) as possible. Most of the time is spent in secure places-in burrows or dense thickets, for example, or in naturally protected spots such as steep mountain slopes or ledges (bighorn sheep and mountain goats). If predators are removed, then the quest for security ceases to be the leading reg ...
PDF
... This first salient island characteristic, isolation, leads to the second, biotic depauperization. The relative simplicity of insular biotas allows interactions amongpopulations to be deduced which would be obscured in a more complex mainland context. For example, that addition of a predator trophic ...
... This first salient island characteristic, isolation, leads to the second, biotic depauperization. The relative simplicity of insular biotas allows interactions amongpopulations to be deduced which would be obscured in a more complex mainland context. For example, that addition of a predator trophic ...
Does diversity beget diversity? A case study of crops
... Keywords: Agroecosystems; Habitat heterogeneity; Niche limitation; Species richness. Nomenclature: Kartesz (1994). ...
... Keywords: Agroecosystems; Habitat heterogeneity; Niche limitation; Species richness. Nomenclature: Kartesz (1994). ...
Genetic identity of interspecific neighbours mediates plant
... to represent the range of abundance of the initial 16 genotypes after 5 years in simulated single-genotype microcosms as reported in Booth & Grime (2003). Selection of the Campanula genotype (Cr13) was based upon its potential for clonal spread. Whitlock (2004), using microsatellite markers, has est ...
... to represent the range of abundance of the initial 16 genotypes after 5 years in simulated single-genotype microcosms as reported in Booth & Grime (2003). Selection of the Campanula genotype (Cr13) was based upon its potential for clonal spread. Whitlock (2004), using microsatellite markers, has est ...
Species Invasions Exceed Extinctions on Islands Worldwide: A
... MacArthur and Wilson 1967), which posits that an increase in the immigration rate of species (in this case, nonnative ones) should lead to an increase in richness. If this prediction is correct, then the relative change in richness of a region should be related to the relative change in rates of imm ...
... MacArthur and Wilson 1967), which posits that an increase in the immigration rate of species (in this case, nonnative ones) should lead to an increase in richness. If this prediction is correct, then the relative change in richness of a region should be related to the relative change in rates of imm ...
Audio transcript
... What is biodiversity? It’s one of those concepts that most people think they know what it means, but if you ask different people you will get really quite different definitions of what biodiversity actually is. Part of the reason for this is that it is quite an abstract concept. It means approximate ...
... What is biodiversity? It’s one of those concepts that most people think they know what it means, but if you ask different people you will get really quite different definitions of what biodiversity actually is. Part of the reason for this is that it is quite an abstract concept. It means approximate ...
Biodiversity
... Most biologists agree however that the period since human emergence is part of a new mass extinction, named the Holocene extinction event, caused primarily by the impact humans are having on the environment.[37] It has been argued that the present rate of extinction is sufficient to eliminate most s ...
... Most biologists agree however that the period since human emergence is part of a new mass extinction, named the Holocene extinction event, caused primarily by the impact humans are having on the environment.[37] It has been argued that the present rate of extinction is sufficient to eliminate most s ...
Chapter 5
... their rapid growth and after their deaths during the decaying process. Other organisms in the water suffocate. ...
... their rapid growth and after their deaths during the decaying process. Other organisms in the water suffocate. ...
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms (taxon), normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly ""reappears"" (typically in the fossil record) after a period of apparent absence.The age of the Earth is about 4.54 billion years old. The earliest undisputed evidence of life on Earth dates at least from 3.5 billion years ago, during the Eoarchean Era after a geological crust started to solidify following the earlier molten Hadean Eon. There are microbial mat fossils found in 3.48 billion-year-old sandstone discovered in Western Australia. Other early physical evidence of a biogenic substance is graphite in 3.7 billion-year-old metasedimentary rocks discovered in Western Greenland. More than 99 percent of all species, amounting to over five billion species, that ever lived on Earth are estimated to be extinct. Estimates on the number of Earth's current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described.Through evolution, species arise through the process of speciation—where new varieties of organisms arise and thrive when they are able to find and exploit an ecological niche—and species become extinct when they are no longer able to survive in changing conditions or against superior competition. The relationship between animals and their ecological niches has been firmly established. A typical species becomes extinct within 10 million years of its first appearance, although some species, called living fossils, survive with virtually no morphological change for hundreds of millions of years. Mass extinctions are relatively rare events; however, isolated extinctions are quite common. Only recently have extinctions been recorded and scientists have become alarmed at the current high rate of extinctions. Most species that become extinct are never scientifically documented. Some scientists estimate that up to half of presently existing plant and animal species may become extinct by 2100.