BIOL 3130 Lecture : Conservation Biology - 9. Habitat Fragmentation

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ochreherring44

23 Mar 2012

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Detachment or separation of expansive tracts into spatially segregated fragments. Parks are becoming islands, surrounded by developed areas. The fragmentation process: perforation, dissection, fragmentation, shrinkage, attrition. Effects of reduction in area of remaining fragments. Effects of increasing disturbance from surrounding area (edge effects). Theory of island biogeography (macarthur and wilson 1967) Community-based model that incorporates both island (patch) size and isolation. Hypothesizes that the number of species on an island is a function of rate of colonization and rate of extinction. Mostly written about oceanic islands; mostly applied to habitat fragmentation. One or both changes have the same effect: species loss. Key message: diversity can decline strictly by reduced dispersal. Conservation bio implications: this model easily represented population dynamics that took into consideration the main factors that determine existence. It graphically made sense and it could easily be applied to fragmented habits instead of only oceanic islands. It also explains why extinction occurs in fragmented habitats (terrestrial as well)

Related Questions

One consequence of an expanding human population is thefragmentation of other species ranges. Describe the majorconsequences of habitat fragmentation in terms of populationgenetic variation and extinction probability. Contrast theconsequences of current habitat fragmentation with the vicarianceevents that occurred during the Pleistocene

taupewasp705

1. The creation of phylogenetic trees from molecular data hasfacilitated the study of many questions in evolutionary biology.Describe one example of how having a phylogenetic tree has added toour understanding of either speciation or adaptation (note: forspeciation it is not sufficient to simply determine how species arerelated to each other). Be sure to compare how this question wouldbe studied in the absence of a robust phylogeny with what is gainedby having a phylogeny for the group.

2. One consequence of an expanding human population is thefragmentation of other species ranges. Describe the majorconsequences of habitat fragmentation in terms of populationgenetic variation and extinction probability. Contrast theconsequences of current habitat fragmentation with the vicarianceevents that occurred during the Pleistocene