A framework for evaluating the diversity status of trees, shrubs and vines in a tropical forest in Mexico based on landscape pattern metrics and spatial modelling with GIS

This thesis identifies and characterizes the relationships among landscape structures and plant diversity in a tropical forest landscape in Quintana Roo, Mexico. Several diversity measures and vegetation classes were used to relate alpha and beta diversity indices as a strategy for mapping plant diversity in a tropical landscape mosaic. The number of species, the exponent Shannon and the reciprocal Simpson indices were calculated from 141 sampling quadrats (16543 individuals sampled) while the vegetation classes were obtained from classification and ordination of sample units as well as from multi-spectral satellite image classification. The performances of means of mapped classes, inverse distance functions, and kriging were compared to obtain an optimal map of plant diversity. In addition, the relationships between landscape patterns and plant diversity indices were explored to find out reliable predictors of plant diversity. My findings revealed that the plant diversity of the landscape depends, to a large extent, on the diversity contained in the mature forest class. However, the high and moderate beta diversity values found between vegetation classes indicated the contribution of those classes to the total diversity. On the other hand, the stratified kriging interpolator yielded the most accurate estimates of plant diversity indices, with the added advantage of providing interpretations of structural analysis that can be used in conservation planning and decision-making. Finally, the quality of the surrounding habitats that reflects the degree of fragmentation of habitats as well as the proximity and distance between such elements, which represents the degree of isolation that they had, were the two main factors that explained the patterns of distribution of plant species in the studied area.