User:Skiploom/SLOSS debate

SLOSS debate draft:

Single Large

A single large approach may be necessary when a species experiences negative consequences associated with Edge effects. Edge effects can be apparent in smaller patches where the ratio of edge to interior area is larger. Compared to birds in continuous forest habitats, birds in fragmented habitats experienced less species diversity. Birds that inhabit interior habitats differ from birds that inhabit edge habitats, therefore as edge to interior habitat ratios increase with smaller patch sizes, bird diversity decreases. One study on tropical amphibian diversity found that continuous, non-fragmented habitats had the highest levels of diversity. In addition, larger habitat fragments had higher species diversity compared to smaller fragments. It was found that for populations of toads, genetic diversity decreased with decreasing patch size.

Several Small

Beta Diversity could help explain why several small patches can contain more species diversity than one large patch. It is possible that different habitat patches house different species if beta diversity is high. Large-scale factors affecting habitat patches such as habitat diversity across multiple patches can oppose the effects of smaller patches. In addition, in some cases there can be positive responses to habitat fragmentation. In a review of significant fragmentation effects, it was found that up to 76% were positive effects.

Other

There could be other factors affecting conservation in habitat patches other than the size of the patch. For example, quality of a habitat patch could outweigh the size component of the patch.

Single Large or Several Small Pros and Cons Outline:

- Single Large:


 * Edge Effects: There are negative consequences associated with the increased edge area of smaller patches. Larger habitat patches do not experience as much of these consequences.
 * Compared to birds in continuous forest habitats, birds in fragmented habitats experienced less species diversity. Birds that inhabit interior habitats differ from birds that inhabit edge habitats, therefore as edge to interior habitat ratios increase with smaller patch sizes, bird diversity decreases.
 * One study on tropical amphibian diversity found that continuous, non-fragmented habitats had the highest levels of diversity. In addition, larger habitat fragments had higher species diversity compared to smaller fragments.
 * It was found that for populations of toads, genetic diversity decreased with decreasing patch size.

- Several Small:


 * Beta Diversity: Beta diversity could help explain why several small patches can contain more species diversity than one large patch.
 * In some cases there can be positive responses to habitat fragmentation. In a review of significant fragmentation effects, it was found that up to 76% were positive effects.
 * Large-scale factors affecting habitat patches such as habitat diversity across multiple patches can oppose the effects of smaller patches.

-Other:


 * Quality of a habitat patch could outweigh the size component of the patch.