The Roach Brain Lab
for studying biodiversity through molecular systematics
Biodiversity of Guyana
My research in Guyana consists of understanding the ecological processes that generate and maintain biodiversity.
I have approached this in preliminary investigations regarding: the role of niche partitioning among sympatric species, niche shifting as a driver of speciation and how dispersal ability affects large scale biodiversity patterns. These are projects I will address in the future.
For my dissertation I completed two major investigations of biodiversity:
How landscape organization affects community assembly
How species delimitation affects our perception of biodiversity in a communty perspective
Landscape Ecology of the Rupununi and the Forest Refuge Hypothesis
The north Rupununi of Guyana is an expansive a savanna-forest matrix. During the wet season, large regions of both forest and savanna are flooded, fragmenting the landscape. These spatial and temporal elements could have ecological consequences for taxa that are displaced by floods and limited by hot, exposed savanna. Leaf litter cockroaches may be such taxa, as savannas would impose water limitation and floods would severely reduce available habitat.
This system is generally applicable to the forest refuge hypothesis, one proposed hypothesis to explain amazonian mega-diversity. In a 2017 paper in Insect Conservation and Diversity we looked at how different landscape elements (savanna, forest main-lands, forest islands, flood regions) act as boundaries to dispersal in some species. This corroborates the proposed mechanism driving the forest refuge hypothesis.
How species delimitation affects species richness estimates
Species richness is a common ecological statistic, as it is simply to calculate and expected to be indicative of certain habitat qualities. Extrapolating total richness from known richness usually relies on the abundances of species, particularly rare species. Although these methods are widely used, ecologists tend to ignore uncertainty in their species identities.
In a 2014 paper published in Systematic Entomology, we compared richness estimates of two different data sets of cockroach community abundances. One data set (M) was grouped into species-level taxa based only on morphological information. The second (M+G) was grouped using DNA barcodes in addition to the morphological information. We showed that richness estimates varied considerably among the two datasets.