Human Impact on the Environment Key Definitions

Endangered species

A species which is at serious risk of becoming extinct

Extinct

A species which has no living individuals e.g. Dodo

Alien species

A species introduced to a habitat by man.

SSSI

Site of Special Scientific Interest. (UK landowners have a duty to maintain them)

CITES

Convention on International Trade in Endangered Species - it is illegal in most countries to buy/sell endangered species. By reducing demand, declining numbers may recover.

Gene pool

All the alleles of all genes in a population.

Conservation

The protection, preservation, management and restoration of natural habitats and their ecological communities, to enhance biodiversity while allowing for suitable human activity.

Gene banks

Frozen seeds, sperm and tissue samples which can be stored indefinitely to ensure that the alleles present will be available to add characteristic or genetic diversity to future gene pools.

Monocultures

The growth of large numbers of genetically identical crop plants in a defined area.

Deforestation

Removal of trees at a faster rathe than they are being re-planted/can regenerate (afforestation)

Sustainable forestry

Where trees are replaced/replanted or a sufficient regeneration time is allowed so that trees can be harvested indefinitely.

Selective cutting

Felling only some trees, leaving others in place.

Coppicing

Cutting down of trees close to the ground and leaving them to re-grow for 5-7 years.

Overfishing

The rate at which fish are harvested exceeds the rate at which they reproduce.

Environmental Impact Assessment

Predicted environmental effect of any proposed development. (Should be carried out by disinterested expert third party)

Planetary Boundaries

Limits between which global systems must operate to prevent abrupt and irreversible environmental change.

Ecotourism

Responsible travel to natural areas that conserves the environment and improves well-being of local people.

Non-contiguous populations

The total number of individuals in a species may suggest that numbers are sufficient to ensure the continuation of the species but if groups are isolated from each other, they cannot interbreed and each group functions as a separate population. Can result in lack of genetic diversity and extinction.