BIOL 5C Species Diversity

What are the three complexity in Biological systems?

• population

  • group of individuals of a single species living in the same area or location

• Community

  • group of individuals of different species living together in a particular area

• Ecosystem

  • a community plus all the abiotic factors influencing that community

What are the subsets in studying communities?

• taxonomic group: mammals, platyhelminths, insects, etc

• ecological guilds: Herbivores, predators, pollinators, parasites, etc

Methods and sampling effort: Data - real numbers (raw data), indices, log_2, ln, log transformed

How do you quantify diversity in communities?

• Species richness: the number of species in a community

• Relative abundances: The proportion of individuals in a community represented by each species

What are rank-abundance curves?

A curve that plots the relative abundance of each species in a community in rank order from the most abundant species to the least abundant species

What is species evenness?

The degree of similarity in relative abundance of species in a community.

What is alpha diversity?

Species Richness: Number of species in a community or in a defined area

Ex: Number of fish species IN A LAKE in California

What is gamma diversity?

Richness over a larger geographic area

• number of fish species in ALL LAKES in california

• compare the # of fish species in Californian lake vs the # of fish species in the lakes of Texas

What is beta diversity?

relates alpha to gamma diversity. Represents the rate of change of species composition among an environment or geographic gradient

= gamma / average alpha