| Biology 141 Lewis & Clark College | | K.E. Clifton |
Threats to biodiversity come from many factors, especially habitat loss, fragmentation and the introduction of exotic species.
Reserves, or protected areas may reduce the impact of these factors.
Classifying reserves:
Who they protect
Single species
Umbrella species
Flagship species
Keystone species
Specific habitats
Issues of concern:
How big an area to protect... or more importantly, how many organisms to protect
Why population size matters
Minimum Viable Population Size
Inbreeding depression
Genetic bottlenecks (should we protect genetic diversity?)
Other reasons to think about reserve size:
Home range issues and trophic position
Minimum Viable Area
Recall our concept of sustainability: the managed use of resources such that they are replaced at the rate they are depleted
How to achieve sustainable consumption?
1) Reduce rate of consumption to match renewal rate
Recycling may complement natural renewal (see coral reefs for a good example of this occuring naturally)
Fisheries and Forestry science predicated on this aspect of resource management
2) Set aside areas (Reserves)
The role of ecology in the design of reserves:
Some basic concepts
Cores and buffer zones
Nodes and corridors
What this translates into: 3 needs
Representation
Replication
Connectivity