A comparison of leaf litter diversity in wet and dry
It is difficult to quantify tropical
forest diversity without the skills of a trained taxonomist to
identify species. What can we learn about tropical forest diversity
by sampling dead leaves from the forest floor? We separated leaves
collected from 0.25 m2 quadrats into morphospecies and weighed them.
We found an average of ~ 22 morphospecies in each quadrat regardless
of location. We identified nearly 80 different kinds of leaves at La
Selva, compared to only 30 at Palo Verde. Consequently, the Palo
Verde samples were much more similar to each other (had a much higher
Sorenson Community Coefficient). There was, however, no correlation
between this measure of quadrat similarity and distance between
samples in either forest. Species area curves from Palo Verde suggest
that our 2m2 sample yielded most of the species in the plot; by
contrast, our La Selva species area curves were similar to typical
wet forest curves in that they showed little evidence of saturation.
As expected, we found the wet forest at La Selva to be more diverse
than the dry forest at Palo Verde. Sampling leaf litter is an
effective (if tedious) way to assess forest diversity.