A key feature of the LEF's ecosystems is disturbance. Hurricanes, landslides, and human disturbance have shaped the forest, and research by LUQ has stimulated a new appreciation of the significance of large-scale disturbances in tropical forested ecosystems and the key role of plants and animals in shaping the response to these events (see Disturbance and Recovery, Landslides, Forest Dynamics). Hurricanes occurring one and 10 years after LUQ began in 1988 provided landscape-scale natural experiments which are still followed closely.
Among the most important findings from these natural experiments is that detrital dynamics plays a central role in forest recovery by influencing carbon and nutrient storage and flow. Therefore, in the context of the overall research goal, the most recent research questions are:
- How do climatic factors, litter quality, and detritivore diversity regulate decomposition of detrital pulses?
- How do terrestrial and aquatic food webs differ in their response to detrital pulses?
- What is the effect of disturbance frequency on nutrient cycling, plant community composition, and the accumulation of soil organic matter?
- To what degree is the export of carbon and nutrients from watersheds a result of soil characteristics that are affected by detrital dynamics?
- How do elevationally related changes in climate impact plant and detritivore communities, and how do these feed back on the quantity and quality of litter inputs and decomposition?
The LUQ research plan for answering these questions is based on:
- Long-term measurements of forest and stream response to natural and anthropogenic disturbance
- Associated short- and long-term manipulative experiments to develop a process-level understanding of results from our long-term measurements
- Validation of this understanding through parallel experiments and measurements along gradients of climate and species richness
- Comparison of results from LUQ with other LTER and non-LTER sites (see Proposals, and Methods for detailed protocols)
This work addresses critical issues about global climate change, tropical forest carbon dynamics, and changes in biodiversity by:
- Chronicling the effects of repeated hurricane disturbance and climatic gradients on the long-term dynamics of a tropical forest ecosystem
- Providing long-term assessments of carbon storage in tropical biomass and soils
- Examining the degree to which species and functional groups contribute to detrital dynamics and the ability of an ecosystem to recover following disturbance.
By extending an understanding of the LEF to other disturbance-driven systems, LUQ is making significant contribution to our knowledge of the mechanisms by which disturbance structures ecosystems.