Tropical forests 4: Protected areas Flashcards
What are the two main considerations for protected areas?
Where to put them and whether the diversity will be maintained
What is the theoretical basis for the design of protected areas?
Island biogeography
What does island biogeography explain?
The species richness of islands
What are ecological islands? Give three examples
Islands are isolated ecosystems. They can be actual islands, mountains in deserts, and protected areas surrounded by unsuitable habitat
Give three processes that interact in islands
Immigration, colonisation, extinction
What causes variation in these three processes?
Island topography, size, orientation, substrate
Why does the number of species on an island increase with island size?
The rate of extinction decreases
What is the aim of the reserve design?
Increase immigration and reproduction and decrease emigration and mortality
How is a larger protected area better than a smaller one?
More biodiversity by: fewer edge effects, can support larger populations, more species, less extinction in larger species, wide rage of habitats, less vulnerable to disturbance
What are edge effects?
Periphery is more likely to have a lower quality habitat, exotic species invasion, different microclimate, and avoidance by interior species
What is SLOSS
Single large or several small.
Single large areas vulnerable e.g. to extreme weather.
Several small areas experience more edge effects.
What dictates the connectivity between reserves?
The permeability of the matrix
What is matrix quality the result of?
The danger it poses to dispersing species and characteristics that stop species from entering it
What is the meta-population theory?
If individuals can move between reserves, the populations can be managed collectively as a meta-population
How does habitat patch size relate to population size?
A large habitat patch size is positively correlated with population size
Why are larger populations less vulnerable to extinction?
Demographic and environmental stochasticity
What else can reduce the risk of extinction in reserves?
Increased connectivity between pitches
What is habitat fragmentation?
Where a large habitat is broken up into smaller habitats that are isolated from each other
What can be used to mitigate the effects of habitat fragmentation?
Habitat corridors
How do habitat corridors mitigate effects of habitat fragmentation?
Provide additional habitat, increase recolonisation potentional, increase individual survival, increase gene flow
What is the least cost path in relation to habitat corridors?
The path that allows highest permeability with the highest movement probability
What did Bruner at al (2001) conclude about the effectiveness of protected areas?
Most PAs are successful at stopping land clearing. The effectiveness depends on level of management activities. Increased funding would increase ability to protect biodiversity.
What did Wade et al (2020) conclude about the effectiveness of protected forests?
Protected forests have lower rates of loss than non-protected ones. (Most loss in tropics is for agriculture and loss in northern latitudes is from wildfires, pests, storms)
