In the image below, assume the different colors represent different species of fish. The gamma diversity was 818 for kerala and 524 for karnataka. Gamma diversity is a measure of the overall diversity for the di erent ecosystems within a region. Ill try to break it down to make it at simple as possible. The alpha diversity of site a is 3 because there are. Alpha, beta and gamma diversity in details youtube.
Gamma diversity result along the altitudinal gradient showed that alpha diversity was higher than beta diversity. The multiplicative definition also fails for many indices for the same reason. Beta diversity patterns were rather comparable with alpha and gamma diversity, which contradicts with the hypothesis h 3. For each group, gamma diversity was estimated by the total number of plant species encountered in those fields, while alpha diversity was the mean species richness per field. Alpha diversity, community, dissimilarity, gamma diversity, spatial extent, spatial grain, sorensen, species turnover. It is considered to be the overall diversity of a group of areas of alpha diversity. Comparing two classes of alpha diversities and their. The study of alpha, beta and gamma components of the diversity are useful for measuring and monitoring the effects of human activities on biodiversity, such as fragmentation 343536.
The latitudinal distribution patterns of alpha, beta and gamma diversity of reptiles, amphibians and herpetofauna were analyzed using individual binary models of potential distribution for. It is defined as the diversity of a larger unit such as an island or landscape. Gamma diversity landscape diversity or diversity of habitats within a landscape or region. Shrub habitat enhanced alpha species richness per plot and beta diversity resulting in greater gamma diversity for the community as a whole, with twice as many species associated with the shrub localscale patterns in species richness the holy grail of ecology. The same tranformation also converts gamma entropy to true gamma diversity. Gamma diversity diversity due to differences in samples when all samples combined e. Regardless of how it is measured, beta diversity re. Alpha diversity is the number of species found in a particular area or ecosystem. Latitudinal trends of all scales of diversity were similar in all groups. Tuomisto recently suggested using the average plotlevel species richness as a measure for alpha diversity, the relation of gamma diversity and alpha diversity as a measure of beta diversity where gamma diversity is the total number of species observed within a data set as a measure of gamma diversity. Here gamma diversity is the total species diversity of a landscape and alpha diversity is the mean species diversity per habitat. Beta diversity index showed a positive relationship with alpha index, indicating dependence of beta on alpha values. Pdf alpha, beta and gamma diversity of the birds in a.
Whittaker 1972 described three terms for measuring biodiversity over spatial scales. What is the difference between alpha, beta, and gamma diversity. Landscape gamma diversity and fieldscale alpha diversity plant species richness were calculated for each group of fields along the landscape complexity gradient. Gamma diversity equals alpha diversity x beta diversity. Alpha diversity is just the diversity of each site local species pool. Many researchers use these terms and they are part of the ecological vocabulary. The alpha diversity of site a is 3 because there are three different species at site a. Beta diversity is defined as the difference in species composition between communities and. Alpha diversity refers to the average species diversity in a habitat or specific area. Alpha, beta and gamma diversity of fished marine taxa. Along with individual species, functional group diversity also enhances ecosystem stability bai et al. Beta diversity represents the differences in species composition among sites. Alpha, beta and gamma diversity differ in response to. Species diversity as a surrogate for global biodiversity 8.
The plant diversity of aapa mires which was the highest in lcbd and high to intermediate at alpha and gamma levels followed the expectations best figure 4. Alpha, beta and gamma diversity request pdf researchgate. In this video alpha, beta and gamma diversity is discussed briefly. The simplest of whittakers original definitions of beta diversity is. Alpha and beta diversity were assessed in icelandic tundra valleys at several spatial scales. We conclude with a set of recommendations on the use of diversity partitioning. Seed dispersal shapes ecological and evolutionary dynamics of plant populations.
Use of alpha, beta, and gamma diversity measures to. Alpha diversity and gamma diversity can be viewed as expressions of a continuum of floristic composition at different spatial scales. In the example below, the greatest beta diversity is observed between site a and c with 10 species that differ between them and only 2 species in common. Therefore, if beta is defined as gamma minus alpha, beta must approach 0 whenever alpha diversity is high, regardless of the turnover between samples.
This talk will be about patterns of species diversity. Landscape complexity differentially affects alpha, beta. The relation between the shannon alpha, beta, and gamma entropy follows directly from information theory. Alpha, beta and gamma diversity and their development alpha and gamma diversity as whittaker 1960 noted, alpha and gamma diversity are descriptors of species within one certain area, but they differ in the units considered. Lande 1996, following lewontin 1972, pointed out that the partitioning of gamma into alpha and beta only makes sense if alpha were always less than or equal to gamma for a given diversity index. Species richness and evenness decreased with altitude, but the patterns within the altitudinal gradient varied between sites, including a sudden decrease at high altitude. Altitudinal distribution of alpha, beta, and gamma. We focus on the decomposition of diversity as measured by hill numbers parameterized by a diversity order q. Main focus is on the difference in taxonomic abundance profiles from different samples. Alpha, beta and gamma diversity for hypothetical species of birds in three different ecosystems hypothetical species woodland habitat hedgerow habitat open field habitat a x b x c x d x e x f x x g x x h x x i x x j x x k x l x x m x n x alpha diversity 10 7 3 beta diversity woodland vs. While the arthropod diversity was similar in kerala and karnataka, the chordate and mollusc diversity was higher in kerala.
Gamma diversity is the total diversity of a landscape and is a combination of both alpha and beta diversity. This functional diversity has hinted at a similar diversity in the inputs each motoneuron receives, as well as in the electrical, or cellular, properties of the motoneurons that match the properties of their muscle targets. Variability itself can be partitioned into alpha, beta, and gamma components to relate dynamics within and across local communities to metacommunity stability. Patterns of alpha, beta and gamma diversity of the herpetofauna in. This video is helpful for csir net biology, neet medical preparation, west bengal school service biological science preparation. Beta diversity is commonly expressed as the ratio whittaker 1960, 1972 or the difference lande 1996 between gamma and alpha diversity.
Request pdf on jan 1, 2004, ian harrison and others published alpha, beta and gamma diversity find, read and cite all the research you need on researchgate. Alpha, beta, and gamma diversity biology libretexts. Genetic diversity genetic diversity refers to any variation in the nucleotides, genes, chromosomes, or whole genomes of organisms. In this example, the gamma diversity is 3 habitats with 12 species total diversity. Diversity partitioning, which decomposes gamma diversity into alpha and beta components, is commonly used to obtain measures that quantify spatialtemporal diversity and compositional similarity or dissimilarity among assemblages.
The phanerozoic record of alpha diversity has been. Alpha diversity is measured within a sample in whittakers original notion, a stand or. Pdf use of alpha, beta, and gamma diversity measures to. Patterns of alpha, beta and gamma diversity of the herpetofauna in mexicos pacific lowlands and adjacent interior valleys. Gamma diversity and alpha diversity can be calculated directly from species inventory data. Inventory, differentiation, and proportional diversity. Alpha and gamma responded inversely to latitude whereas beta showed a high latitudinal. This is the fundamental currency of diversity williams and humphries, 1996 and the basis for all other organismal diversity. Half a century ago, whittaker first defined species diversity from three different perspectives. From diversity indices to community assembly processes.
The term beta diversity has been used to refer to a wide variety of phenomena. Use of alpha, beta, and gamma diversity measures to characterize seed dispersal by animals. Beta diversity changes in sample composition along an environmental gradient e. Otherwise, beta diversity via complementaritywould be the main.
Pdf understanding the distribution pattern and maintenance mechanism of species diversity along environmental gradients is essential for developing. Beta diversity is a comparison of diversity between ecosystems usually measured as the amount of. Landforms contribute to plant biodiversity at alpha, beta. Pdf predicting alpha, beta and gamma plant diversity. Habitat and climate heterogeneity maintain beta diversity of birds among landscapes within ecoregions. Alpha, beta, and nowgamma david blanchett, cfa, cfp head of retirement research morningstar investment management paul kaplan, ph. Species richness patterns in the diversity of life.
Whittaker 1970 named the spatial measures of richness alpha, beta, gamma. Latitudinal gradients deep time and mass extinctions hotspots and coldspots. Beta diversity shows the different between microbial communities from different environments. Alpha diversity refers to the diversity within a particular area or ecosystem, and is usually expressed by the number of species i. Beta diversity is defined as the difference in species composition. Like the alpha entropy, it can be converted to the true beta diversity by eq. Pdf alpha, beta and gamma diversity differ in response to. What is the difference between alpha, beta, and gamma. Partitioning diversity into independent alpha and beta. Whittakers idea was that the total species diversity in a landscape. Alpha diversity is usually thought of as biological diversity at one site or sampling location. Predicting alpha, beta and gamma plant diversity from physiognomic and physical indicators as a tool for ecosystem monitoring. The results highlighted the importance of defining habitats explicitly.
Using three taxonomic groups of beetles we examine how alpha and beta diversity influence the species richness of a landscape gamma diversity, and vice. Genetic diversity is the sum total of genetic information, contained in the genes of. Request pdf on jan 1, 2004, ian harrison and others published alpha, beta and gamma diversity find, read and cite all the research you need on. Microbiome101 tracymeiring medicalvirology universityofcapetown instuteofinfecousdiseasesandmolecular medicine.