Comparing species richness, functional diversity and. As foundation species or species groups decline, associated. Although empirical evidence in natural plant communities demonstrates that pathogens can specialize at the level of species, our experiment in panama demonstrates. Different diversity indices apportion different relative weights to these properties, and the definition of evenness itself varies. The evenness of the sample is obtained from the formula. Species diversity refers to species richness and how evenly species abundance is distributed. Pdf on jun 1, 2000, owen l petchey and others published species diversity, species extinction, and ecosystem function find, read and cite all the research you need on researchgate. Difficult to define because definition consists of two distinct components. Additionally, the introduction of species into new ecosystems destroys natural balance.
Species diversity species diversity differs from species richness in that it takes into account both the numbers of species present and the dominance or evenness of species in relation to one another. Alpha, beta, and gamma diversity biology libretexts. Species diversity and functional diversity relationship varies with disturbance intensity shekhar r. Intertidal zonation does species diversity decrease with. The methods on offer range from the familiar, such as the calculation of various diversity indices and the fitting of common distributions, to more recentlydeveloped techniques such as total species complement estimators. In all of the plots installed, all trees with diameter at breast height. The number of species that live in a certain location is called species. What is the difference between species richness and. To examine this, the student removed the keystone predator at one location in the reef community and left the other location alone. The main difference between species diversity and ecosystem diversity is that the species diversity is the variety of species in a particular region whereas the ecosystem diversity is the variety of ecosystems in a particular area species diversity and ecosystem diversity, along with genetic diversity, are the three levels of biodiversity on the earth. Species abundance or evenness describes relative abundance of species.
Jul 20, 2018 drivers of species richness and functional diversity. For example, if we are monitoring the effect that british farming practices have on. In addition, the dominance of species changed noticeably. However, many species differ significantly in their abundance among stages. Species diversity is a term used to define the different number of species in an area species richness and its abundance and the distribution of these species in that ecosystem. C the more species you have, the more diverse the area.
Species richness, species abundance and species diversity. B based on the species richness the number of species present and species. The key difference between species richness and species diversity is that species diversity has two components namely species richness and species evenness whereas species richness is a part of species diversity. May 30, 2017 the key difference between species richness and species diversity is that species diversity has two components namely species richness and species evenness whereas species richness is a part of species diversity. It represents the species richness or number of species found in an ecological community, the abundance or number of individuals per species, and the distribution or evenness of species. Main difference genetic diversity vs species diversity. Species richness variety of species or the number of different species or genera, families, etc. B based on the species richness the number of species present and species abundance the number of individuals per species. Species richness within families of flowering plants. Species diversity takes into consideration species richness, which is the total number of different species in a community. The importance of species diversity to the ecosystem. Species diversity is measured in relation to a given area from a small field to the entire planet.
Species richness the number of species that live in a certain location. Species diversity is the number of different species that are represented in a given community a dataset. Species density or the number of species per m 2 is most commonly used to measure species richness. Tree species diversity, richness, and similarity in intact. Different diversity indices apportion different relative weights to these properties, and the definition of. The relationship between productivity and species richness.
It also takes into account evenness, which is the variation of abundance in individuals per species in a community. Species richness means the variability number of species within a region ec. Difference between biodiversity and species richness. For example, in the image below, we can see that these two communities are. Biogeographic region components of species diversity. Species richness is the simplest way to describe community and regional diversity, and this variable number of species forms the basis of many ecological models of community structure 55. This is important when were trying to discover how an ecosystem works, and how important different. The key difference between biodiversity and species richness is that biodiversity refers to the variety of life found in a specific place on earth or the total variety of life on earth while species richness refers to the number of different species represented in an ecological community, landscape or region biodiversity and species richness are two different terms in ecology. For example, in the image below, we can see that these two.
Species diversity and functional diversity relationship. Species abundance is the number of individuals per species, and relative abundance refers to the evenness of distribution of individuals among species in. Mcintosh 1967 coined the name species richness to describe this concept. Mapping species richness new mexico energy, minerals and. The maximum diversity hmax of a sample is found when all species are equally abundant. The diversity of our biosphere ranges from macromolecules of a cell to different biomes. Keystone species play an important role, both in maintaining species diversity and the health of an ecosystem. Overexploitation, pollution and habitat conversion are the main threats to species diversity. The relationship between species diversity and functional diversity is a fundamental topic in. Species diversity is a measurement of biological diversity to be found in a specific ecological community. The mean number of species, and 95% confidence interval, is 6.
Drivers of species richness and functional diversity. As a measure of species diversity, we will calculate the shannon index, h. Species diversity is defined as the number of species and amplitude of each species that live in a particular location or ecological community. Genetic diversity, species diversity, and ecological diversity are three types of biodiversity. A keystone species is an organism that helps maintain species diversity within an ecosystem by keeping the numbers of other species in an ecosystem constant. Species diversity and richness 4 is designed for professional ecologists and their students. Species diversity indices take two aspects of a community into account, namely species richness and evenness or equitability the distribution of abundance among the species. The variety of life forms of a particular area are referred to as biodiversity. Apr 09, 2019 consistent with this, a recent empirical study of genetic diversity of tropical tree species at our field site showed that tree species with a higher diversity of pathogen resistance genes suffered less from soil pathogens and negative densitydependent mortality than species with lower resistance gene diversity and were more abundant in the. Species diversity is determined not only by the number of species within a biological communityi. An ecology student was curious about the effect of a keystone predator on the community structure of a coral reef community. Species evenness measures how evenly the species are represented in the area.
Habitat heterogeneity, species diversity and null models. Trees species diversity, richness, and similarity were studied in fifteen plots of the tropical rainforests in the northeast of the republic of congo, based on trees inventories conducted on fifteen 0. Quantitative approaches two approaches have been used to determine the effects of habitat heterogeneity on species diversity. Functional diversity fd, species richness and community. Species richness possesses intuitive mathematical properties, and features prominently in foundational models of community ecology. Species composition is the identity of all the different organisms that make up a community. Simulating species trait values illustrates how the relative importance of richness and composition for fd depends on the effective dimensionality of the trait space in which species separate. Species diversity, stand structure, and species distribution. Species diversity is a major determinant of ecosystem productivity, stability, invasibility, and nutrient dynamics. Difference between species richness and species diversity. Species diversity associated with foundation species in. Species richness, as measure of diversity, has been used by ecologists. Species abundance is the number of individuals per species, and relative abundance refers to the evenness of. The importance of species diversity to the ecosystem sciencing.
Species diversity is a measure of diversity within an ecological community that encompasses both species richness and evenness of species abundance hamilton, 2005. Variation in species and genus richness among families of flowering plants was examined with respect to four classification variables. One quantifies the linear relationship between species diversity and habitat diversity macarthur and macarthur 1961. A majority of these showed greatest abundance in old growth. What is the difference between species diversity and. Species richness sr per lake ranged from seven to 26 mean. Various characteristics of fd make it preferable to other measures of functional diversity, such as the number of functional groups in a community. G roth2 1department of ecology, evolution and behavior, university of minnesota, st. Species diversity refers to the measure of diversity in an ecological community. Sep 23, 2016 species abundance is the number of individuals of each species in an individual. Oct 30, 2017 main difference genetic diversity vs species diversity. Pdf species diversity, species extinction, and ecosystem.
Hundreds of studies spanning terrestrial, aquatic, and marine ecosystems show that highdiversity mixtures are approximately twice as. The most abundant species in this zone are semibalanus cariosis with 1,760 individuals, and balanus glandula with 982 individuals. Species diversity is the number of different species that are represented in a given community. The key difference between biodiversity and species richness is that biodiversity refers to the variety of life found in a specific place on earth or the total variety of life on earth while species richness refers to the number of different species represented in an ecological community, landscape or region. Species richness is the number of species present in a sample, ecological community, ecosystem, landscape, region, or any defined spatial unit. The smallest sample size may be 1 km and the largest may be the entire region or country. Primary industries research victoriaknoxfield, private bag 15, ferntree gully delivery centre, victoria. Quantifying species richness is important, not only for basic comparisons among sites, but also for addressing the saturation of local communities colonized from. Evenness we can compare the actual diversity value to the maximum possible diversity by using a measure called evenness. It can be assessed in terms of the number of species or the range of different types of species an area contains. The relationship between species diversityrichness and community stability is quite complex. It is widely known from agriculture that pathogens can specialize on genotypes within plant species, but such highly specialized pathogens have rarely been studied in natural plant communities. Species diversity is defined as the number of species and abundance of each species that live in a particular location.
The species richness of the mussel zone totals thirteen separate species with 4,270 individuals. The relationship between species diversity richness and community stability is quite complex. Journal of wildlife management, plant species biology, endangered species research, mammalian species, international journal for parasitology. Species diversity list of high impact articles ppts. Each open bar is the average diversity in one of eight experimental disturbance regimes, and the solid bar is the average diversity in unmanipulated controls c n7 replicatestreatment. Mallik department of biology, lakehead university, 955 oliver road, thunder bay, ontario p7b5e1 canada abstract. They cause a gradual loss of species on local, regional and global levels. Pdf species diversity, functional diversity and ecosystem. What is the difference between species richness and species. Species richness refers to the number of species in an area. Meanings of species diversity may include species richness, taxonomic or phylogenetic.
On the other hand, species diversity is a function of the number of species present i. By not allowing one species or another to become overly dominant, a keystone. One quantifies the linear relationship between species diversity and habitat diversity macarthur and macarthur 1961, macarthur 1964, rosenzweig and winakur 1969. A a diversity index is a mathematical measure of species diversity in a given community. Realted journals of species diversity journal of wildlife management, plant species biology, endangered species research, mammalian species, international journal for parasitology. The drop in diversity at high levels of severity in ypmc forests and other similar ecosystems adapted to frequent, low. This approach is problematic because the relationship between habitat and species diversities may be nonlinear.
Alpha diversity refers to the diversity within a particular area or ecosystem, and is usually expressed by the number of species i. Evidence of withinspecies specialization by soil microbes. A total of 39 waterbird species were recorded in the floodplain lakes. Species abundance refers to the number of individuals per species. Whittaker 1972 described three terms for measuring biodiversity over spatial scales. Species richness an index based on the number of species i. May 17, 2002 various characteristics of fd make it preferable to other measures of functional diversity, such as the number of functional groups in a community. Pdf on jan 1, 2005, andrew j hamilton and others published species diversity or biodiversity. Difference between genetic diversity and species diversity. The effective number of species refers to the number of equally abundant species needed to obtain the same mean proportional species abundance as that observed in the dataset of interest where all species may not be equally abundant. Nov 04, 2018 the main difference between species diversity and ecosystem diversity is that the species diversity is the variety of species in a particular region whereas the ecosystem diversity is the variety of ecosystems in a particular area. Few understory species are restricted to, or absent from, any stage of stand development i. Species abundance is the number of individuals of each species in an individual. Previous studies have estimated rates of species proliferation from age and contemporary diversity.
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