Species Richness
Species Richness - Related Videos
10:14
Species Distribution and Biogeography - Student Protocol
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2019
Simulating Colonization and Extinction on Islands ExpandForm groups of three. One member of the group will simulate colonization by throwing balls into the groups of cups representing the islands. Another will simulate extinction by rolling dice to randomly remove balls from the cups. The third group member will record the data. Take time to familiarize yourself with the four island stations. NOTE: There are two large islands with 12 cups and two small islands with 6 cups. Two of the stations...
04:04
Species Distribution and Biogeography - Concepts
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2019
Species Distribution Biogeography is the study of species distribution across geographic space and the processes that shape these distributions. This discipline is based on the assumption that each species within a location must have immigrated from another geographic area or evolved from a local species. Within each habitat, a variety of biotic and abiotic factors act on individual species to shape birth, death, immigration, and emigration rates. To avoid local extinction, the combined birth...
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Characterization of Leukocyte-platelet Rich Fibrin, A Novel Biomaterial
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Cited by 38 •
2015
Leucocyte-Platelet Rich Fibrin (L-PRF) represents an FDA cleared preparation of autologous platelet concentrates that possesses unique fibrin architecture, enriched platelets and abundant growth factors. Here, we present a protocol for chair-side generation of L-PRF as well as evaluate its mechanical properties including uniaxial testing and suture retention strength testing.
01:17
Understanding Species and Reproductive Barriers
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2026
A species is a group of organisms that interbreed and produce fertile offspring. Typically, individuals of the same species appear similar and share common characteristics due to their highly similar genomes. However, not all organisms that look alike are members of the same species. Various mechanisms keep most species discrete. While some mechanisms prevent reproductive behavior and fertilization (pre-zygotic isolation), others prevent the production of fertile offspring after mating has...
09:08
Detecting Reactive Oxygen Species
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2023
Reactive oxygen species are chemically active, oxygen-derived molecules capable of oxidizing other molecules. Because of their reactive nature, there are many deleterious effects associated with unchecked ROS production, including structural damage to DNA and other biological molecules. However, ROS can also be mediators of physiological signaling. There is accumulating evidence that ROS play significant roles in everything from activation of transcription factors to the mediation of...
FAQs
Sampling effort directly affects observed species richness because surveys with more sampled area or time provide more opportunities to encounter uncommon species. For that reason, comparisons should use standardized sampling areas or time periods. Researchers can then distinguish differences among communities from differences caused simply by unequal survey intensity.
Habitat size is an important comparison factor because communities surveyed across areas of different extent may not receive equivalent sampling opportunities. Interpreting richness alongside habitat size helps researchers evaluate whether an apparent difference reflects the communities themselves or the scope of the area examined. This improves comparisons across geographic regions and habitats.
Species richness records how many species occur, but it does not show how individuals are distributed among those species. Two communities can therefore have the same richness while differing in evenness, meaning the balance of individuals among species. Considering both measures gives a more informative picture of community structure and biodiversity than richness alone.
A basic assessment establishes a defined community, habitat, or geographic area, then surveys organisms within standardized sampling areas or time periods. Investigators record the different species encountered and consider whether rare species may have gone undetected. Accounting for sampling effort and detection likelihood makes the resulting estimate more suitable for comparison.
Comparing species richness among ecosystems, environmental gradients, or disturbance regimes can reveal how biological diversity varies across conditions. The value of the comparison depends on consistent sampling and attention to habitat size and undetected rare species. Interpreted carefully, the results help identify broad spatial or environmental patterns rather than merely differences in survey design.
Conservation planning uses species richness comparisons to help identify areas containing high biological diversity. These assessments can guide attention toward habitats or geographic regions that support many different species. Because richness does not describe species distribution or guarantee complete detection, planners gain a stronger basis for decisions when they also consider evenness and survey limitations.