PROJECTS IN SE ASIA

Most of my research is based in the Malaysian state of Sabah on the island of Borneo. I work with the amazing field team at the Malua Field Station near the Danum Valley Field Centre, which is part of the Southeast Asian Rainforest Research Program (SEARRP). Below are my ongoing research areas, which cover a spectrum of ecological topics from ecophysiology to plant-climate interactions:

FOREST DYNAMICS IN A MAST SYSTEM

The lowland dipterocarp forests found throughout Borneo experience a unique reproductive phenomenon called “general mast flowering”. During these events, flowering occurs across species, genera and families creating both an ecologically rare and aesthetically beautiful (see video below) process. However, our knowledge regarding many aspects of these events remains limited. What are the climatic ques that trigger these events? Can we predict when and how big these events will be? What processes control seed survival and germination during the seed fall? What is the relative importance of the different processes for determining seedling recruitment? All of these questions are far from being answered but are crucial for understanding regeneration under future climates and for informing restoration plans for recovering previously logged forest.

My research examines seed and seedling fate during and after mast fruit production. I use a network of 81 plots which have been monitored for seed and seedling mortality and growth regularly since the 2010 masting event. it now includes two additional masting events (2014 and 2019). This research can begin to examine the long-term dynamics of seedling communities and the mechanisms that influence mortality and growth through time. See the seeds falling: Seed rain during collection

CLIMATE-CHANGE INDUCED DROUGHT

Drought in Borneo is commonly associated with El Niño Southern Oscillation events (ENSO), and these events are predicted to increase in both severity and frequency in the future. Therefore, although annual rainfall is expected to increase in Southeast Asia, variability in rainfall (more days with no rain and more days with extreme rain) and drought are expected to occur more regularly. I have planted seedling communities into gap and understory plots around the Malua Forest Field Station and applied drought using clear plastic sheeting rain shelters. I have multiple projects assessing drought effects on dipterocarp seedlings (see my 2017 article in Global Change Biology for details).

Drought does not operate independent of other variables and in order for us to begin to understand the impacts altered climates will have on tree, we need to assess the role of climate in conjunction with plant-plant interactions, plant-soil interactions and plant-herbivore interactions. I have permanent plots throughout the Malua forest that have seedlings growing within three different neighborhood communities from individuals to monocultures to diverse mixtures. I have expanded this research to new projects that incorporate seedling genetic diversity and topography. These projects will develop a more comprehensive understanding of the factors that mediate responses to drought of seedling communities.

PROJECTS IN SPAIN

During 2020, I initiated a mapping of 50-hectares in oak dehesa woodlands in collaboration with Dr. Christian Schöb. In total, we mapped more than 1200 trees consisting mostly of Quercus ilex. We have added regeneration treatments throughout the plots to examine the role of canopy cover and shrubs for mediating seed germination and seedling growth and survival.

PROJECTS IN COSTA RICA

In 2016, I began collaborating with Dr. Jennifer Powers at the University of Minnesota on her projects in Guanacaste, Costa Rica, which is predominantly covered with tropical-dry forest. Together with the Powers Lab, I have been addressing resilience of seedfall to El Niño-induced drought and seedling establishment following these events in tropical dry forests. The Powers Lab has amazing facilities, research assistants and graduate student that are assessing a wide-range of ecological issues in tropical-dry forests. The research is based out of the Estación Experimental Forestal Horizontes. They have been an amazing group, and I will update this page as our research develops.