BISC 313 Lecture Notes - Lecture 13: Distichlis Spicata, Juncus, Spartina
1 Nov 2017
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Document Summary
Species both facilitate and inhibit each other: facilitation: earlier speces modify the environment in ways that benefit later species, common changes include: light availability, soil nutrients, space, organic matter, moisture, competition, Inhibition: earlier species modify the environment in ways that hinder colonization of later species predation: new england salt marsh: secondary succession. Salt marshes have different species compositions and physical conditions at different tidal elevations. Spike grass, distichlis spicata, is often the first to colonize, but is eventually outcompeted by both spartina and juncus in their respective zones: bertness and shumway (1993) manipulated patches after they had been colonized. Communities can follow different successional paths and display alternative states. A community is thought to be stable when it returns to its original state after perturbation because they are resistant or resilient to change. Stability partly depends on the scale of observation, both spatial and temporal. Sometimes different communities develop in the same area under similar environmental conditions-- alternative stable states.
