BIOL3007 Lecture Notes - Lecture 1: Niche Differentiation, Character Displacement, Commensalism
Document Summary
Types of competition: at least two species, either using or seeking the same resource, resource competition: scramble or exploitative competition. Resource in common is limited (e. g. water, tree hollows. ) Resource in common is not necessarily limited but individuals harm each other getting it (e. g. competition for mates, interspecific attacks). Co-existence: example: tilaman 1977, looking at resource competition (si/p) between plankton algae. Asterionella can use phosphate at a lower concentration (higher si/p) and cyclotella can use silicate at a much lower concentration (higher p/si). There was coexistence in most of the nutrient ratios and at certain concentrations, each species dominated. Coexistence can only occur when limited by different resources. Emphasized the role of resources in determining competitive outcomes and demonstrated co-existence can occur when the limiting resources differ. Complete exclusion: gause hypothesis: complete competitors cannot co-exist. (this is rare). If a complete niche overlaps, one species will outcompete the other.
