8 - Community interactions

23 bio 3115 universit dottawa university of ottawa

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Unformatted text preview: ana Zooplankton (cladocerans, copepods) Phytoplankton Kokanee salmon Bald eagle Grizzly bear L8.24 Bio 3115 Université d’Ottawa / University of Ottawa M8..12 BIO 3115 Conservation Biology 3/11/2014 Disruption of the food web in Flathead Lake and its tributaries by the introduction of opossum shrimp (Mysis relicta). Abundance 150 Kokanee salmon (X 1000) Bald eagles (X 7) Mysis (per m2) 100 50 0 1981 1983 1985 1987 1989 1989 Year L8.25 Bio 3115 Université d’Ottawa / University of Ottawa Extinction cascades: the Hawaiian experience Hawaiian meliphagids, drepanidids Hawaiian hawk Goats Pigs Nectar-producing plants Extinctions 3 meliphagids (known) 2 melaphagids (probable) 2 drepanidids 1 hawk L8.26 Bio 3115 Université d’Ottawa / University of Ottawa M8..13 BIO 3115 Conservation Biology 3/11/2014 Characteristics of successful invaders high r, dispersal rates vegetative or clonal reproduction (plants) habitat generalist broad diet (polyphagous) wide (native) distribution L8.27 Bio 3115 Université d’Ottawa / University of Ottawa Some (very general!) features of invadable communities low diversity absence of predators of invaders absence of ecologically similar native species simple food webs anthropogenically disturbed L8.28 Bio 3115 Université d’Ottawa / University of Ottawa M8..14 BIO 3115 Conservation Biology 3/11/2014 The effect of species removal depends on complexity and position in food web R R Loss of chain (goats, pigs, Hawaiian meliphagids) No secondary effect (e.g. Peregrine falcon) L8.29 Bio 3115 Université d’Ottawa / University of Ottawa The effect of species removal depends on complexity and position in food web (cont’d) R R Little secondary effect (e.g. American chesnut) Loss of several plant species L8.30 Bio 3115 Université d’Ottawa / University of Ottawa M8..15 BIO 3115 Conservation Biology 3/11/2014 Number of introductions Changes in the rate of mammal introductions to islands and continents between 1700 and 1985 120 Continents Islands 60 0 ? 16511700 17011750 17511800 18011850 18511900 19011950 19511985 L8.31 Bio 3115 Université d’Ottawa / University of...
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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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