3 Flashcards
Biodiversity
The overall term fro three different but inter-related types of diversity: genetic, species and habitat.
Species Diversity
The products of two variables: the richness and evenness of species in an area.
Genetic Diversity
The range of genetic material present in a gene pool or population of a species.
Habitat Diversity
The range of different habitats per unit area in a particular ecosystem.
Hotspot
A biodiversity hotspot is a region with a high level of biodiversity that is under thereat from human activities.
Factors Which Cause Loss of Biodiversity
Natural hazards, Natural disasters, Environmental destruction, Habitat destruction, Fragmentation of habitat, Pollution, Invasive species, Disease, Modern Agricultural Practices.
Why is a Species Prone to Extinction
Narrow geographical range.
Small population size.
Low population densities and large territories.
Few Populations.
Large body.
Low reproductive potential.
Seasonal migrants.
Poor dispersers.
Specialised feeders or Niche requirements.
Edible to humans and living in large groups, herds.
Island organisms.
ICUN Redlist
EX
EW
CR
EN
VU
NT
LC
DD
NE
Value of Biodiveristy
Direct:
Food services and natural products.
Indirect:
Environmental services, scientific and educational value, biological control agents, gene pools, future potential uses, human health, human rights, recreational, ecotourism, intrinsic value, biorights.
Conservation Biology
The sustainable use and management of natural resources. Anthropocentric.
Preservation Biology
Attempts to exclude human activity in areas wgere humans hae not yet encroached. Ecocentric.
Sustainable Development
Meeting the needs of the present without negatively impacting the needs of future generations and biodiversity.
IGOs
Composed of, and answering to a group of member states.
UN, IPCC.
GOs
Part of and funded by a national government.
Environmental Protection Agency of the USA (EPA).
NGOs
Not for profit. International or local, funded by the people.
Friends of the Earth, Greenpeace.
Natural Hazard
Naturally occurring events that may have a negative impact on the environment (and humans). Volcanic Eruptions, Earthquakes, Floods.
Natural Disaster
A natural hazard whose impact is very bad, or affect human populations significantly. Eruption of MT ST Helens, Washington State, USA, 1980, Haiti 2010, Yangtze river floods, china, 2007.
Environmental Disaster
Cause by anthropogenic activities which significantly affect the environment. Deforestation of TR and Oil Spills.
Speciation
The gradual change of a species over a long time. When populations of the same species become separated, they cannot interbreed and if the environments they inhabit change they may start to diverge and a new species forms. Separation may have geographical or reproductive causes.
Examples of Geographical Isolation
Physical Barriers, mountains or oceans. Land Bridges. Continental Drift.
Factors Which Help Maintain Biodiversity
Complexity of Ecosystem
Stage of Succession
Limiting Factors
Inertia (resist change when subject to a disruptive force)
Extinction Rates
100-10,000 time greater than background rates.
Classified Species < Total number of species, estimates of extinction rates are therefore varied.
Continental Drift
Separating species or bringing them together.
For a species to be considered CE
50-70% decline over three generations or ten years
