Biology 2483A Lecture 16: Change in Communities - Chapter 16
14 Dec 2016
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Document Summary
Effects of eruptions vary depending on distance from the volcano and habitat type. Newly-formed and isolated ponds were colonized by amphibians much faster than was though possible frogs and salamanders were using tunnels created by northern pocket gophers to make their way from one pond to another. Multiple mechanism were responsible for primary succession: facilitation by dwarf lupines on the pumice plain they trap seeds and detritus, and have nitrogen-fixing bacteria. Lupines were inhibited by insect herbivores, which controlled the pace of succession. Tolerance: douglas fir and herbaceous species lived together in some habitats. Communities are always changing, some more than others human actions are becoming one of the strongest forces behind community changes, and we have an imperfect understanding of the consequences of those actions. Agents of change act on communities across all temporal and spatial scales. Succession: the directional change in species composition over time as a result of abiotic and biotic agents of change.
