Current Research
Heterogeneity of soil nutrients and novel tropical forest communitiesSecondary forests are an increasingly dominant forest type in the Caribbean and Latin America. Therefore, the capacity of these forests to supplement the lost functions and services provided by “primary” or old-growth forests in these regions, is of great importance. To determine the services and functions tropical secondary forests are able to provide, we must develop an understanding of the factors that determine successional trajectories of these forests after a disturbance or land-use. After a disturbance or land-use change that leads to forest succession, the resulting changes to soil properties could be crucial in determining the tree species composition in later stages of succession and therefore establishing the ecosystem services and function of the forest. The aim of this project is to determine how important the spatial distribution of soil nutrients is after land-use, in shaping species composition. I will use a chronosequence approach in the island of Puerto Rico, to look at changes in the forest community and soil properties through successional stages. The results from this research will provide an important step to develop mechanistic models of successional trajectories in the tropics. Determining the primary factors that determine tree species composition will allow to develop better management of marginal land that is thought to serve no ecological purpose as many secondary forests develop in abandoned lands.
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Past Research
Habitat fragmentation and floral heritabilityFor my masters thesis I conducted a common garden experiment to study floral morphology heritability of the evening primrose Oenothera harringtonii. This state imperiled species is primarily pollinated by two species of hawkmoth (Hyles lineata and Manduca quinquemaculata). Recent urban development near some populations of O.harringtonii could alter pollinator behavior and abundance non-randomly. If populations of O.harringtonii can respond to novel selective pressures there must be sufficient genetic variation of floral traits. Our study measured the capacity of O.harringtonii populations to respond to selection of floral morphology under a fragmented landscape. We also measured the degree of genetic divergence of floral morphology of populations in fragmented and unfragmented landscapes through analyses of quantitative genetics. Overall our findings show that populations will respond to selection of floral size. Specifically, flowers will be able to either reduce their herkogamy for pollinators with a shorter proboscis or vice versa.
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