What is species diversity with example?

What is species diversity with example?

Species diversity is defined as the number of species and abundance of each species that live in a particular location. Abundance is the number of individuals of each species. For example, there might be 100 mountain beavers that live in a forest.

What increases species diversity?

At regional scales, diversity is also increased by speciation and decreased by extinction. These decreases in diversity include those caused by regional extinction events that extirpate species from the region in question but not necessarily from all other regions.

What are the factors that affect species diversity?

The factors related to these patterns of small- scale species richness include (1) geographic factors such as scale of observation, available species pool and dispersal patterns, (2) biotic factors such as competition or predation and (3) abiotic environmental factors such as site resource availability, disturbance and …

What are the 5 factors that affect biodiversity?

Important direct drivers affecting biodiversity are habitat change, climate change, invasive species, overexploitation, and pollution (CF4, C3, C4. 3, S7).

What are the 2 components of species diversity?

Components of species diversity: species richness and relative abundance.

What is species evenness example?

Evenness is a measure of the relative abundance of the different species making up the richness of an area. To give an example, we might have sampled two different fields for wildflowers. The sample from the first field consists of 300 daisies, 335 dandelions and 365 buttercups.

Why is species diversity important to humans?

Biodiversity is important to humans for many reasons. Ecological life support— biodiversity provides functioning ecosystems that supply oxygen, clean air and water, pollination of plants, pest control, wastewater treatment and many ecosystem services. …

How do you calculate species diversity?

It is calculated from the equation: It is estimated as (ni/N). N is total number of individuals in S species. The value of Shannon index usually varies between 1.5 and 3.5 and rarely exceeds 4.5. The value of H’ is related to species richness but is also influenced by the underlying species abundance distribution.

What is the best indicator of diversity?

Hi, there is no single ‘best’ measure for species diversity. Each index measures a different component of species diversity. Species richness only counts the number of species, while evenness indices only look at the equality in abundances between species. Shannon and Simpson indices take both into account.

Which is measured at species diversity level?

Alpha diversity refers to diversity within a particular area, community or ecosystem, and is measured by counting the number of taxa within the ecosystem (usually species) Beta diversity is species diversity between ecosystems; this involves comparing the number of taxa that are unique to each of the ecosystems.

What is Shannon’s diversity index?

Methods: The Shannon diversity index (H) is another index that is commonly used to characterize species diversity in a community. Like Simpson’s index, Shannon’s index accounts for both abundance and evenness of the species present. Equitability assumes a value between 0 and 1 with 1 being complete evenness.

What is evenness index?

The Shannon evenness index, abbreviated as SEI, provides information on area composition and richness. It covers the number of different land cover types (m) observed along the straight line and their relative abundances (Pi). It is calculated by dividing the Shannon diversity index by its maximum (h (m)).

What does a high Simpson’s Diversity Index mean?

Simpson’s Diversity Index is a measure of diversity which takes into account the number of species present, as well as the relative abundance of each species. As species richness and evenness increase, so diversity increases. With this index, 1 represents infinite diversity and 0, no diversity.

How is Shannon’s index calculated?

Take the natural logarithm of each proportion (lnp) and then multiply the proportion and the ln of the proportion (p*lnp). Add these values together, take the negative value of it (to make it positive) and you will have your Shannon Weiner index score (H’).

What does diversity index mean?

A diversity index (also called phylogenetic or Simpson’s Diversity Index) is a quantitative measure that reflects how many different types (such as species) there are in a dataset (a community) and that can simultaneously take into account the phylogenetic relations among the individuals distributed among those types.

What is Chao1 index?

Chao1 is a nonparametric method for estimating the number of species in a community. The Chao richness estimator was developed by Anne Chao and is based on the concept that rare species infer the most information about the number of missing species.

What is a rarefaction curve?

In ecology, rarefaction is a technique to assess species richness from the results of sampling. Rarefaction curves are created by randomly re-sampling the pool of N samples multiple times and then plotting the average number of species found in each sample (1,2, N).

What is Faith’s phylogenetic diversity?

The most widely used phylogenetic metric is Faith’s phylogenetic diversity (PD) (Faith 1992) which is defined as the sum of the branch lengths of a phylogenetic tree connecting all species in the target assemblage.

What is the difference between alpha and beta diversity?

Alpha diversity is the species diversity present within each forest or grassland patch of the slope. Beta diversity is represented by the species diversity between any two patches and their communities. Gamma diversity of the landscape is the species diversity along the entire range of the mountain slope.

What is a high beta diversity?

Beta diversity measures the change in diversity of species from one environment to another. A high beta diversity index indicates a low level of similarity, while a low beta diversity index shows a high level of similarity.

What does alpha diversity indicate?

Alpha diversity refers to the diversity within a particular area or ecosystem, and is usually expressed by the number of species (i.e., species richness) in that ecosystem. Gamma diversity is a measure of the overall diversity for the different ecosystems within a region.

Which region has greatest diversity?

Species diversity is greatest in the tropics, particularly in tropical forests and coral reefs. The Amazon basin in South America has the largest area of tropical forests. The southwestern Pacific has the greatest diver- sity of coral reef species.

Which region on the planet Earth is rich in species diversity?

Tropical region

What is the most diverse country on earth?

The Most Diverse Countries in the World

• Papua New Guinea. Papua New Guinea might be a small country, with a population of fewer than 9 million people.
• Democratic Republic of Congo. This Central African country has a population of approximately 5.5 million people.
• South Africa.
• Madagascar.
• American Samoa.
• Aruba.

What is the least biodiverse country on earth?

the arctic biome

Which country has the least birds?

Country with the fewest species of birds: Easter Island (is that a country?) with 9 species (and 0 endemics).