Habitat Fragmentation (Exam 2)

habitat fragmentation

breaking apart of continuous habitat into distinct pieces
3 things happen: reduction, subdivision, change

reduction

total amount of habitat decreases (habitat loss)

subdivision

remaining habitat is split up (fragmentation)

change

new forms of land-use replace the old habitat

species richness is a function of what 4 factors?

island remoteness, immigration, island size, extinction

island remoteness

proximity of island to other populations
nearshore island have higher immigration and vice versa

island size

area and how many different species can survive
small islands will have higher extinction and vice versa

landscape ecology

expands spacial context of fragments
fragments do not exist in a void -- they are influenced by processes in the wider landscape

landscape change continuum

describes change from no modification to complete habitat loss

percentage of habitat

amount of habitat in landscape

percentage of fragmentation/edge

proportion of edge habitat in landscape

patch density

number of patches in a landscape

cohesion index

structural connectedness of patches in the landscape

what dynamic changes result from fragmentation?

decrease in total area of habitat
decrease in overall size of fragments
increase in distance between fragments

where does fragmentation occur fastest?

flat, dry, fertile land

edge effects

physical processes (rain, wind, light, temp) are all elevated in edge habitats