Malagasy Grass Diversity Population Genomics

The extent to which grasslands may have expanded and contracted in response to natural climate cycles versus more recent agricultural practices remains an open question in the Central Highland Plateau of Madagascar. Demographic analyses of diverse grass species from Madagascar can serve as a case study for differentiating the impacts of past climate change from recent anthropogenic effects in a geographically controlled setting. By taking advantage of the ecological specificity of closed-canopy forest and open-habitat grass species, historical demographic analysis can reveal patterns consistent with a fluctuating environment, and potentially identify the timing and extent of grassland expansions and contractions. To investigate these temporal and ecological dynamics, the project will: 1) Resolve the phylogenetic history and taxonomy of ecologically important Malagasy grass lineages; 2) reconstruct the population dynamics of endemic C3 and C4 grasses as a proxy for grassland expansion and contraction through time; and 3) compare populations of a C4 species that is ecologically dominant in both Malagasy and African savannas to determine the extent to which grasslands have been shaped by climatic trends that prevailed in the southern hemisphere versus local effects such as slash-and-burn agriculture.