Research
Fragmented Forest Dynamics in Sri Lanka
Tropical forests are some of the most carbon-dense and biodiverse ecosystems on Earth, yet they face ongoing deforestation which causes forest fragmentation or the break up of contiguous forest into smaller and smaller patches. Forest fragmentation is projected to increase in the future which is concerning because forest degradation within forests tends to happen more rapidly in fragments than in contiguous forests. An estimated 30% of tropical forest carbon emissions result from degradation within forests, which complicates global efforts to achieve climate mitigation and biodiversity conservation targets.
While neotropical forests are relatively well-studied, fragmented tropical forests in South and Southeast Asia receive far less attention, despite the fact that undisturbed primary forests in this region store up to three times more carbon per unit area. The legacy of clearing South Asian rainforests for plantation agriculture combined with high population pressure has created a complex mosaic of forest fragments, which differs significantly from the physical and socio-economic context of tropical Latin America, where large-scale industrial land use dominates.
My research seeks to understand the pathways of forest degradation and recovery in fragmented landscapes, with the goal of identifying management strategies that mitigate these threats. In collaboration with Uva Wellasa University and the Sri Lankan Forest Department, I am studying the forest dynamics of a fragmented landscape in southwestern Sri Lanka. Here, large patches of primary mixed-dipterocarp rainforest are interspersed with human-dominated smallholder farms and secondary forest fragments. This landscape is emblematic of many fragmented regions in South and Southeast Asia, where human activities have shaped forest remnants in ways that differ from the industrially driven fragmentation seen in Latin America.
Key questions remain about how forests recover and evolve in fragmented landscapes, and how human land-use practices influence this process. My research addresses these issues by exploring how succession occurs in fragmented forests, the role of local land use in shaping forest recovery, and which management practices can promote biodiversity and carbon sequestration. I recently published a study on biomass dynamics in forest fragments (Woodbury et al., 2024), and I am preparing another manuscript on species composition dynamics (Woodbury et al., in prep). These studies show that fragments which are more intensively managed by local people have higher aboveground biomass stocks and a different set of species that contribute to higher landscape scale species richness in fragments than the primary forest. We also find a higher presence of trees with high human utility value in more intensively managed fragments. These results suggest that human influence has a strong influence on the structure and composition of fragmented forests.
In response, my research in this landscape is increasingly interdisciplinary as I integrate human values into my studies. I plan to explore the relationship between carbon storage in forest fragments and their historical land use. With access to seventy years of government land records, aerial imagery, and surveys on local villager’s forest values, I have a unique opportunity to examine how forest fragment conditions and their carbon storage potential are linked to their historical context and the socio-economic landscape around them.
This novel interdisciplinary approach aims to uncover how the legacy of land use shapes forest fragments today and how community values influence forest conservation. The findings could have significant implications for conservation strategies, enabling us to enhance carbon sequestration by tailoring management interventions to land use history and the current needs and values of local communities. Through this work, we hope to provide a model for how socio-economic and historical factors can be leveraged to inform more effective, locally grounded conservation approaches.
While neotropical forests are relatively well-studied, fragmented tropical forests in South and Southeast Asia receive far less attention, despite the fact that undisturbed primary forests in this region store up to three times more carbon per unit area. The legacy of clearing South Asian rainforests for plantation agriculture combined with high population pressure has created a complex mosaic of forest fragments, which differs significantly from the physical and socio-economic context of tropical Latin America, where large-scale industrial land use dominates.
My research seeks to understand the pathways of forest degradation and recovery in fragmented landscapes, with the goal of identifying management strategies that mitigate these threats. In collaboration with Uva Wellasa University and the Sri Lankan Forest Department, I am studying the forest dynamics of a fragmented landscape in southwestern Sri Lanka. Here, large patches of primary mixed-dipterocarp rainforest are interspersed with human-dominated smallholder farms and secondary forest fragments. This landscape is emblematic of many fragmented regions in South and Southeast Asia, where human activities have shaped forest remnants in ways that differ from the industrially driven fragmentation seen in Latin America.
Key questions remain about how forests recover and evolve in fragmented landscapes, and how human land-use practices influence this process. My research addresses these issues by exploring how succession occurs in fragmented forests, the role of local land use in shaping forest recovery, and which management practices can promote biodiversity and carbon sequestration. I recently published a study on biomass dynamics in forest fragments (Woodbury et al., 2024), and I am preparing another manuscript on species composition dynamics (Woodbury et al., in prep). These studies show that fragments which are more intensively managed by local people have higher aboveground biomass stocks and a different set of species that contribute to higher landscape scale species richness in fragments than the primary forest. We also find a higher presence of trees with high human utility value in more intensively managed fragments. These results suggest that human influence has a strong influence on the structure and composition of fragmented forests.
In response, my research in this landscape is increasingly interdisciplinary as I integrate human values into my studies. I plan to explore the relationship between carbon storage in forest fragments and their historical land use. With access to seventy years of government land records, aerial imagery, and surveys on local villager’s forest values, I have a unique opportunity to examine how forest fragment conditions and their carbon storage potential are linked to their historical context and the socio-economic landscape around them.
This novel interdisciplinary approach aims to uncover how the legacy of land use shapes forest fragments today and how community values influence forest conservation. The findings could have significant implications for conservation strategies, enabling us to enhance carbon sequestration by tailoring management interventions to land use history and the current needs and values of local communities. Through this work, we hope to provide a model for how socio-economic and historical factors can be leveraged to inform more effective, locally grounded conservation approaches.
Long-term Gap Dynamics in southern new england
Understanding forest succession is essential for shaping effective forest management, yet long-term studies that validate these models are rare due to the logistical challenges of collecting data over decades. Classic dendrochronology studies, which informed the widely used model of forest stand dynamics, originated in temperate oak-hickory forests of Connecticut. While these studies have advanced our understanding of tree growth and competition in stratified forests, they are limited in their ability to capture the dynamics of early successional or vulnerable species that may have been present before sampling began but have since died out.
In these same temperate hardwood forests, we now have access to long-term data on forest succession in gaps, spanning multiple decades. One of our recent studies used over 50 years of data from experimental forest gaps to investigate how tree position within a gap influences growth and competition among species (Martin et al., 2020). Our findings confirmed the predictions of the stand dynamics model, showing that early-successional, shade-intolerant species initially dominated in high-light conditions but were quickly overtaken by shade-intermediate species. Shade-tolerant species, meanwhile, persisted in the lower canopy layers. Interestingly, we found that gap position significantly influenced productivity, with the highest basal area, height, and species richness occurring at gap centers. This is likely due to competition for moisture and nutrients near the gap edges, challenging the common assumption that light is the primary limiting factor in gap dynamics, as most previous studies only track early seedling establishment and growth.
Building on this work, we are now evaluating another long-term dataset on tree regeneration in linear experimental gaps, which spans almost thirty years. We are also analyzing data on oak seedling growth and survival in the understory, where seedlings have been monitored annually for over thirty years. We even have some live oak seedlings less than 10 centimeters tall that were in our initial measurements! Writing up these findings will allow us to provide valuable insights into silvicultural practices in Northeastern hardwood forests, ultimately contributing to the development of management strategies that foster forest resilience in the face of future changes.
In these same temperate hardwood forests, we now have access to long-term data on forest succession in gaps, spanning multiple decades. One of our recent studies used over 50 years of data from experimental forest gaps to investigate how tree position within a gap influences growth and competition among species (Martin et al., 2020). Our findings confirmed the predictions of the stand dynamics model, showing that early-successional, shade-intolerant species initially dominated in high-light conditions but were quickly overtaken by shade-intermediate species. Shade-tolerant species, meanwhile, persisted in the lower canopy layers. Interestingly, we found that gap position significantly influenced productivity, with the highest basal area, height, and species richness occurring at gap centers. This is likely due to competition for moisture and nutrients near the gap edges, challenging the common assumption that light is the primary limiting factor in gap dynamics, as most previous studies only track early seedling establishment and growth.
Building on this work, we are now evaluating another long-term dataset on tree regeneration in linear experimental gaps, which spans almost thirty years. We are also analyzing data on oak seedling growth and survival in the understory, where seedlings have been monitored annually for over thirty years. We even have some live oak seedlings less than 10 centimeters tall that were in our initial measurements! Writing up these findings will allow us to provide valuable insights into silvicultural practices in Northeastern hardwood forests, ultimately contributing to the development of management strategies that foster forest resilience in the face of future changes.