Conservation Biology

As the human population has grown, and our use of resources has increased, we have destroyed the habitat of many species. A biodiversity crisis has developed. The Red List of Threatened Species, compiled by the World Conservation Union, lists 16,913 species as threatened with extinction. Conservation biology—the scientific study of phenomena that affect the maintenance,…

Energy Production: Primary production, Gross primary production, Net primary production

The term ecosystem was first used by Tansley (1935) to refer to all the components of an ecological system, biotic and abiotic, that influence the flow of energy and elements. The ecosystem concept integrates ecology with other disciplines such as geochemistry, hydrology, and atmospheric science. Primary production is the chemical energy generated by autotrophs during…

Ecology: Population Distribution and Abundance

Distribution: Geographic area where individuals of a species occur. Abundance: Number of individuals in a given area. Ecologists try to understand what factors determine the distribution and abundance of species. Populations are dynamic—distribution and abundance can change over time and space. ***Understanding the factors that influence these dynamics helps us manage populations for harvest or…

Life History: Diversity, Reproduction, K vs. R species, Tradeoffs

An organism’s life history is a record of events relating to its growth, development, reproduction, and survival. Life history characteristics include: Age and size at sexual maturity. Amount and timing of reproduction. Survival and mortality rates. Life History Diversity Individuals within a species show variation in life history traits due to genetic variation or environmental…