| Resumo: |
Land legislation has changed dramatically in Mexico during recent years, putting greater emphasis on the integration of free market policies into local production methods. In a country like Mexico, replacement of traditional methods of production may result in the loss of practices that protect the natural environment. With the objective of providing baseline information for future conservation and/or land management programs, I evaluated how landscape patterning and the richness of bird and mammal species varied among current land ownership sizes and types, applying a stratified scheme that controlled for potential variation among different physiographic regions. I characterized landscape spatial patterning using the aggregation index, Shannon's Diversity Index, and the Modified Simpson's Evenness index, and I used the GARP modeling approach to estimate species richness within each land ownership regime. Particular attention was paid to variation among community-based vs. individually based ownership types. A notable finding with regard to parcel size is that there is a general pattern in which medium-to-large parcels contained greater percentages of natural vegetation; this relationship is less consistent for the largest parcels. Regarding land ownership types, community-based lands generally presented higher estimates of habitat conservation, i.e., a higher percentage of natural vegetation, higher aggregation, and more even distribution of land cover types, and a greater richness of bird and mammal species. These results suggest that attention should be paid to evaluating the importance of different types of land ownership in determining spatial patterns of biodiversity. Furthermore, these initial assessments, of how landscape structure and species richness varies across land ownership regimes, serve as reference points for future evaluations of change in landscape and biodiversity spatial patterns in Mexico.
|
