minimum viable population

Minimum Viable Population

• The smallest population for a species which can be expected to survive for a long time

• Many factors effect MVP – the study of those factors is often called Population Viability Analysis – or Population Vulnerability Analysis – or PVA

English Skylark

Metapopulations

Metapopulation

• A series of small, separate populations united together by dispersal

• Thus even if all members of one population go extinct, other populations survive and dispersal from survivor populations can recolonize the area – a rescue effect

Metapopulation Dynamics

Bay Checkerspot Butterfly

Populationdynamicsof BayCheckerspotButterfly

Types of Metapopulations

Habitat Loss

Orange County, California

Habitat Loss• Habitat is the physical and biological

environment used by an individual, a population or a species

• Habitat degradation is the process by which habitat quality for a given species is diminished

• Habitat loss occurs when the habitat quality for a given species is so low that the environment can no longer support the species

Ecosystem Loss

• Ecosystem is a group of organisms and their physical environment

• Ecosystem degradation occurs when alterations to an ecosystem degrade or destroy habitat for many of the species that constitute the ecosystem

• Ecosystem loss occurs when the changes to an ecosystem are so great and so many species typical of that ecosystem (especially dominant species) are lost that the ecosystem switches from one type to another

Processes that degrade habitat and ecosystems

• Contamination• Human built structures• Soil erosion• Changing fire regimes• Human consumption of water

Copper Basin, Tennessee

Copper Basin, Tennessee

1926 1939

Copper Basin today

Copper Basin – Superfund site

Restoration of Burra Burra Pit, Copper Basin

Mid-1990s Mid 2000s

Copper mine tailings, Butte, Montana – largest Superfund site in America

Mine tailings outskirts of Sudbury, Ontario

Restoration of Sudbury

Air pollution – Mexico City

Extent of Acid Precipitation

Rhine River Basin

Healthy Coral Reef

Dying Coral Reefs

Bleached coral Silted out reef

DDT use in 1950s

DDT inZimbabwe

Thin Egg Shells from DDT

Human Built Structures

Pacific or CaliforniaFire-bellied Newt

Pacific or California Fire-bellied Newt –don’t try this at home w/o washing hands

Tilden Park, Berkeley, CA

Snake migration in Shawnee

Copperhead

Dandelion dispersal – along roads and railroads

Bonneville Dam, Columbia River, Oregon

Fish Ladders

The Dingo – Canis familiarus dingo

Dingo Fence – The World’s Longest – New South Wales

Erosion and loss of habitat on Round Island, Mauritius

Smokeythe bear- 1953

Smokey theBear - 1960

EvergladesSurfaceWater Flow