Relationships between floristic diversity and vegetation indices, forest structure and landscape metrics of fragments in Brazilian Cerrado

摘要

Favorable characteristics for development of agricultural activities were crucial factors in the fast substitution of the physiognomy of the Cerrado by agricultural crops and pastures. During this occupation process, the remaining natural vegetation became extremely fragmented and a little is known about the structural and functional integrity even about the species diversity of these ecosystems. The use of vegetation indices as indicators of the forest integrity has been shown to be a useful tool for environmental planning and also for conservation strategies. In this study, we analyzed the correlations between floristic diversity of 22 forests fragments, from diversity indices of Shannon and the equability of Pielou; and the structural parameters of communities represented by basal area and cylindrical volume. Correlations between the diversity and patch metric: AREA, PERIM, GYRATE, PARA, SHAPE, FRAC, CIRCLE, CONTIG, CORE, CAI, PROX and ENN obtained for fragments and among the indices NDVI, SAVI, EVI, MVI5 and MVI7 derived from TM/Landsat images acquired in two seasons were also evaluated. The index which presented strongest correlation with floristic diversity was EVI and the one that showed strongest correlation with the equability was MVI5. The structural parameters basal area and cylindrical volume did not present correlations with diversity and equability. The diversity and equability indices showed correlations with the fragment shape.