(1 9 6 5 ) P h y s io lo g ic a l Z o o lo g y 3 8 : 2 8 9 -3 2 1 Unpredictable Gaps – the poorer competitor is a better coloniser Gaps in a community can be created in any number of ways Can you think of any? Gaps will be colonised – but the first species to do so will not necessarily be best able to exclude other species in the long term So long as gaps are created at an appropriate frequency, it is possible for a “fugitive” and a highly competitive species to co-exist The fugitive species gets to the gap first, establishes itself and reproduces. castaneum Temperature Moisture S E P A R A T E L Y Both species used same flour resources – competition (as we shall see in just a moment) BUT they also preyed preferentially on the eggs, larvae and pupae of the other species – effects of each species on each other greater than on own Reciprocal predation – mutual antagonism P a rk e t a l. When there is co-existence – is it due to current competition, historic process of competition excluding others to leave the current species pair or evolution (“ghost of competition past”) COEXISTENCE – differentiation of realised niches Here K1 K2 α21 > AND Interspecific effects of species 1, greater than intraspecific effects of species 2 Interspecific effects of species 2, greater than intraspecific effects of species 1 What is the OUTCOME? Unstable equilibrium – varies with N0 K2 K1 α12 > Where inter-specific competition is greater than intra-specific competition for BOTH species Mutual Antagonism Where inter-specific competition is greater than intra- specific competition for BOTH species For example…. If there is no differentiation in niches between two species in a stable environment, then one competitor will eliminate or exclude the other. Download Competitive Exclusion Principle - Community Ecology - Lecture Slides and more Ecology and Environment Slides in PDF only on Docsity!FUNDAMENTAL NICHE Species B Environmental Condition or Resource Definition Species A Environmental Condition or Resource REALISED NICHE Definition Species B Species A Environmental Condition or Resource The Competitive Exclusion Principle Here K2 K1 α12 >AND K2 α21 K1> Intraspecific effects of species 2, greater than interspecific effects of species 1 Interspecific effects of species 2, greater than intraspecific effects of species 1 What is the OUTCOME? Species 2 out-competes Species 1 NO COEXISTENCE Acorn Barnacles On Own Fundamental Together Realised PARTITIONING Competitive Exclusion Principle If two species coexist in a stable environment they do so as a result of niche differentiation (i.e.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |