What determines the distribution and abundance of species?
Abiotic and biotic features can interact to determine distribution and abundance. Some species distributions depend on disturbance—events that kill or damage some individuals, creating opportunities for other individuals to grow and reproduce. Example: Some species persist only where there are periodic fires.
What factors affect species abundance?
Many factors affect small-scale species richness, including geographic (e.g. species pool, dispersal), biotic (e.g. competition, predation, facilitation) and abiotic (e.g. resource availability, environmental heterogeneity, disturbance frequency and intensity).
What is the distribution of species within an ecosystem?
The species abundance distribution (SAD) characterizes the distribution of abundances of all species within a sample or ecological community. The observation that most species are relatively rare with only a few being common is often described as one of the few ecological laws (McGill et al. 2007).
What is Fisher’s Alpha?
Fisher’s alpha is a satisfactory scale-independent indicator of biodiversity. However, alpha may be underestimated in communities in which the spatial arrangement of individuals is strongly clustered, or in which the total number of species does not tend to infinity.
What factors influence the distribution of animals?
Factors affecting species distribution
- climatic factors consist of sunlight, atmosphere, humidity, temperature, and salinity;
- edaphic factors are abiotic factors regarding soil, such as the coarseness of soil, local geology, soil pH, and aeration; and.
- social factors include land use and water availability.
How does species distribution help the environment?
They correspond to most of the structure, biomass, and energy flow of terrestrial and marine ecosystems. They profoundly influence the prevailing environmental conditions experienced by other species and thus their coexistence.
What are the factors that affect the diversity and abundance of organism?
A number of evolutionary processes such as selection, gene flow, and historical demography affect the genetic diversity in a population (Hayes and Fox 1991; Boettcher et al. 1995; Bazin et al. 2006). The genetic diversity of individuals within a population affects a range of ecological and evolutionary factors.
What are the 4 factors that influence the species diversity of a particular location?
Such factors include climatic variability, the input of energy, the productivity of the environment, and possibly the ‘age’ of the environment and the ‘harshness’ of the environment. A further group of factors vary geographically but quite independently of latitude (or altitude, island location or depth).
How can species be distributed?
There are three basic types of species distribution within an area: 1) Uniform Species Distribution: in this form the species are evenly spaced. 3)Clumped Species Distribution: this the most common type of dispersion wherein the distance between neighbouring individuals is minimised.
What is species abundance distribution (SAD)?
Species abundance distribution (SAD) is one of the major ecological metrics. SAD curves take a hollow curve or hyperbolic shape on a histogram plot with many rare species and just a few common species. In general, the shape of SAD is largely lognormally distributed.
Why is species abundance distribution shaped like this?
Species abundance distribution (SAD) is one of the major ecological metrics. SAD curves take a hollow curve or hyperbolic shape on a histogram plot with many rare species and just a few common species. In general, the shape of SAD is largely lognormally distributed. The forces that drive SAD to take this shape still remains elusive.
How common is seasonal affective disorder in ecosystems?
The frequency distributions of 19,833 SADs from eight datasets (including eleven taxonomic groups from terrestrial, aquatic, and marine ecosystems) suggest that a general pattern of SAD might exist.