Long-term shifts in plant trait distributions
One of the most prevalent threats faced by tropical forests is the risk of longer and more intense drought events. Tropical dry forests may be particularly vulnerable to climate changes such as rainfall variability, because they experience strong seasonality, they can be very sensitive to water shortage, and they are near climatic thresholds. Nonetheless, our knowledge of how dry forests will respond to climate changes remains scarce due to limited long-term datasets in these ecosystems. Using a theoretical framework called Trait Driver Theory, and long-term data in one of the oldest forest dynamic plot in Neotropical dry forests, I am evaluating how climate change may drive shifts in trait distributions, and whether these shifts influence overall performance of tree species and ecosystem functioning.
Estimating functional diversity using imaging spectroscopy
Airborne remote sensing has been used to assess the extent and composition of forests, and map the chemical diversity across different scales, but estimations of other diversity components such as functional diversity remains a challenge, specifically in hyper diverse systems such as tropical forests. I am currently assessing the potential of airborne imaging to quantify functional diversity of tree communities, and whether these remotely-sensed indices can be used to answer ecological questions related to community assembly and linkages of traits and productivity. This project takes advantage of field and airborne data in an elevation gradient spanning 3,300 m and consisting of tree trait measures taken from 9 1-ha plots in southern Peru.
Ecology and tree dynamics of secondary forests
Secondary forests are becoming increasingly dominant in tropical regions, but our knowledge of the mechanisms structuring biological communities in these ecosystems is quite limited. Secondary forests are also important carbon sinks, but their potential for carbon sequestration is still unclear due to the lack of information on the extent and age distribution of secondary forests. I am part of a collaborative research network called 2ndFor, which focuses on the ecology, biodiversity and dynamics of secondary forests. This network led by Lourens Poorter and Frans Bongers comprises more than 70 researchers working at > 50 study sites in Latin America. Since its creation, the 2ndFor has hugely enhanced our knowledge about the distribution, dynamics, and resilience of secondary forests in the tropics.
Tropical dry forests
Tropical dry forests (TDFs) are broadly defined as a vegetation dominated by deciduous trees, with annual mean temperature higher than 25°C, and annual rainfall of 700-2000 mm/year. TDFs support a larger diversity of life forms than other tropical forests. In contrast to wet forests, TDFS show a lower plant species richness, canopy strata and have more species dispersed by wind than animals. These differences are likely to affect rates of change in vegetation structure and composition. Using data from long-term plots in the Americas in second- and old-growth forests, I focused on understanding the recovery of woody plant diversity and biomass along succession in TDFs, and examine the influence of different diversity components on carbon cycling. This research is part of a collaborative research network Tropi-Dry.
Effects of lianas on aboveground carbon storage in tropical forests
Tropical forests are experiencing changes in composition, structure, and dynamics of woody plants. One of these changes is the increase in liana abundance. Lianas reduce tree growth, inhibit tree regeneration and increase tree mortality; thus they are able to reduce carbon biomass. I used a pan-tropical dataset to disentangle the effects of liana abundance, stand variables (e.g., wood density), and climate on aboveground carbon storage (AGC) in dry, moist and wet tropical forests. I found that stand variables are stronger predictors of AGC, and explain more variation than climate at global scales. I also found negative effects of liana abundance on AGC, specifically in moist forests, which harbor the greatest carbon stocks in the tropics. This research is one of the first studies showing the impacts of lianas on AGC at global scales, and the differential effect of lianas on AGC across tropical forests.