Heat heat primary producers m35 bio 3115 universit

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Unformatted text preview: oducers M3.5 BIO 3115 Université d’Ottawa / University of Ottawa Natural rarity - specialized requirements Some species are naturally rare because they have very specialized habitat requirements. If the required habitat is rare, then so too will be the species in question. E.g. Kirtland’s Warbler requires 10-15 yr old Jack Pine forests for breeding. M3.6 BIO 3115 Université d’Ottawa / University of Ottawa M3 2009-2010.3 BIO 3115 Conservation Biology Natural rarity: specialized requirements, competition Some species are naturally rare because while they can survive outside of particular habitats, they are generally excluded due to interactions with other species (e.g. competition) E.g. McDonald’s rock-cress can only persist on serpentine rock outcrops with high levels of soil magnesium. But it is at a severe competitive disadvantage on normal soils. M3.7 BIO 3115 Université d’Ottawa / University of Ottawa Natural rarity: patchy availability of suitable habitat and limited dispersal Some species are naturally rare because habitable areas are beyond the dispersal range of the species; this is particularly a problem for island endemics. E.g. corral reef fish; coral reefs have more species than tropical forests, but are limited (only 0.2% of the oceans’ surface!); 93% have been damaged and 510% destroyed. M3.8 BIO 3115 Université d’Ottawa / University of Ottawa M3 2009-2010.4 BIO 3115 Conservation Biology Natural rarity; low genetic variability Some species are naturally rare because low genetic variability prevents them from adapting to changing environmental conditions E.g. Furbish’s Lousewort An endemic to Maine, found only in four isolated populations; Lives in unstable habitat patches along riverbanks, and is a poor competitor. Thus, probability of local extinction is very high even at best locations. M3.9 BIO 3115 Université d’Ottawa / University of Ottawa Proportion of species Rarity, population abundance and species richness Within a given area, the proportion of species (in a given taxon) having a population abundance x is often well-approximated by the log-normal distribution f(x) As overall richness increases, the proportion of species with low abundance increases, and average abundance decreases. Higher richness P...
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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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