Biodiversity Environmental Science Notes Series

What is Biodiversity? Species Richness is another term for biodiversity Density is an important factor in terms of biodiversity Carrying capacity: resource availability is important (Tillman curve)

Niche The role of an organisms within its environment (habitat) that is specific. Gause’s competitive exclusion theory – no two organisms (populations) can occupy the same niche indefinitely (Andrews.edu). Niche is important in terms of competition.

Species Abundance? The amount of a particular species in a given habitat is important, this is abundance. Sometimes this does not support species richness if the species out-competes others species.

Biodiversity According to Peter Raven (2007) there are approximately 1.5 million known species on earth with a high extinction rate. There may be 8 – 10 million species on earth today, but not much is known about the lower taxa. Biodiversity is being impacted by humans at an unprecedented rate of extinction of up to 200 species per day.

Competition There are a number of ways in which a species competes for resources: 1. Exploitation: this is when a species can utilize resources better than other species (i.e. Aureococcus) 2. Interference: when a species can create its own environment and manipulate it for its advantage (i.e. Sour weed)

Ecology Ecology is a young field (started in the 1950’s), exploring the role of organisms within their environments and how it relates to survival. Ecology takes into account habitat, environmental factors, biological functions and physical conditions.

Population Estimates Use basic population models… Interspecies: Margelef, Menhenick, Jaccard’s indices Inter/Intraspecies: Simpson’s Index

Island Biogeography Robert MacArthur and Edward O. Wilson, theorized about space and resources looking at islands. They hypothesized that islands further from a mainland would have less species diversity than those closer. They also hypothesized that larger islands would support more diversity than smaller islands.

Sustaining Wild Species Over 90% of today’s crops are domesticated and basically 4 crop types provide a majority of the world its food requirement. Over 80% of the world needs plants for medicinal purposes.

Sustaining Wild Species? Is survival of the human species a key to survival of other species? We look at things from an anthropogenic view. It is thought that over 1 million species live in the rainforests (known) with an extinction rate of 2% per year!

Species protection categories Endangered – reduced mating pairs to the point where populations cannot sustain themselves (Kemp’s ridley sea turtle) Threatened – declining in numbers, but must be protected (Osprey) Concern – Decline, possibly due to habitat loss or resource limitations

Protection Endangered Species Preservation Act (1973): Species are listed under Federal and Statewide basis. Therefore, they could receive protection under different categories. American alligator – Federal Threatened, varies statewide

IUCN: Red List Program The International Union for the Conservation of Nature established a program through the United Nations for global protection of species Under the Red List Program ( has a well organized system of species rankings.

IUCN Red LIST 2007

Protection Enforcement of the Endangered Species Act is a Federal Mandate and falls under the following… –U.S. Fish and Wildlife Service –National Oceanic & Atmospheric Administration, National Marine Fisheries

U.S. Fish & Wildlife Department of the Interior. Responsible for all beaches, inland waters, except Great Lakes. Species management, control and manage lands that are moderately- restricted (over 500 refuges and rangelands).

“NOAA Fisheries Service conserves, protects, and manages living marine resources in a way that ensures their continuation as functioning components of marine ecosystems, affords economic opportunities, and enhances the quality of life for the American public” (NOAA 2007).

NOAA National Estuarine Research Reserve Program Sanctuaries and Protected Areas (called Marine Protected Areas Fisheries Quotas and Enforcement

Other players in management Multiple Use Lands.. National Forests which include over 150 Forests and 19 grasslands managed through the U.S. Forest Service

Other players in management Multiple Use Lands… The largest is the Bureau of Land Management which includes prairies, deserts, scrub forests and open spaces mostly in the western U.S.

Other players in management Restricted Use Lands The National Park Service has over 370 units and 50+ major parks throughout with close to 50% in the wilderness (