8 - Community interactions

16 bio 3115 universit dottawa university of ottawa

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Unformatted text preview: 8 BIO 3115 Conservation Biology 3/11/2014 Historical changes in minnow richness in Gatineau Park lakes Minnow richness has declined dramatically in lakes with introduced piscivores but remained stable in lakes without piscivores … suggesting that introduced piscivores are an important factor in minnow declines L16.17 Bio 3115 Université d’Ottawa / University of Ottawa Extinctions of landbirds by Rattus rattus on Big South Cape Island, New Zealand R. rattus 1962 18 sp. landbirds 1961 18 sp. 10 + (8) 1964 14 sp. 9 + (5) 13 sp. 1965 L8.18 Bio 3115 Université d’Ottawa / University of Ottawa M8..9 BIO 3115 Conservation Biology 3/11/2014 The effects of exotic introductions: community trophic restructuring Exotic introductions result not only in a change in community composition, but also in the trophic structure of communities, and consequently, in the way energy flows. E.g. introduction of Nile Perch into Lake Victoria resulted in large-scale restructuring of endemic fish community. L8.19 Bio 3115 Université d’Ottawa / University of Ottawa Cichlid flocks, Nile Perch and the demise of Lake Victoria fish communities L8.20 Bio 3115 Université d’Ottawa / University of Ottawa M8..10 BIO 3115 Conservation Biology 3/11/2014 Number of species Fish community restructuring in Lake Victoria following introduction of Nile Perch. Other 40 35 Piscivores 30 Mulluscivores 25 Insectivores 20 Zooplanktivores 15 Detritivores/phyto planktivores 10 5 0 1979/80 1981/82 1983/84 1985/86 1987/88 Year L8.21 Bio 3115 Université d’Ottawa / University of Ottawa Spread of Cichla in Gatun Lake, 1969 to 1972 Gatun 1969 1970 1971 1972 Escobal Chagres River Frijoles Gamboa N 5 km L8.22 Bio 3115 Université d’Ottawa / University of Ottawa M8..11 BIO 3115 Conservation Biology 3/11/2014 Trophic structure of Gatun Lake, before and after Cichla introduction A C B M D E F G I J K N H D H I K L L Before introduction After introduction L8.23 Bio 3115 Université d’Ottawa / University of Ottawa The food web of Flathead Lake in Mont...
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This document was uploaded on 03/11/2014 for the course BIO 3115 at University of Ottawa.

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