Wetland Ecology Research

Interactions between vegetation, soil, hydrology and fauna in wetland ecosystems

Complex biotic and abiotic processes govern interactions between vegetation, soil, hydrology and fauna in wetland ecosystems. Vegetation is the major biological component of forested wetlands, influencing many aspects of ecosystem structure, function, and sustainable productivity. It is also the primary target of most management and restoration activities.

However, consideration of the hydrology and soils is also fundamental to the considerations of sustainability. Developing the ability to predict responses to management and the consequent effects on wetland functions is central to developing useful guidelines for management and conservation.

The foundation of the Center’s program is predicted on understanding the hydrologic and biogeochemical cycles as a basis for sustainability. It uses a combination of long-term monitoring, field and laboratory experiments, and modeling to assess specific questions regarding the management and restoration of wetland landscapes.

Vegetation Community Dynamics

Research community composition and dynamics in mixed pine-hardwood forests

How environmental factors (nutrition, water supply, light, and competitive interactions) and land use (agricultural activity, logging history, changes in hydrology, and restoration practices employed) contribute to community composition and dynamics in bottomland hardwood stands, mixed pine-hardwood forests, northern and southern wet pine forests and plantations, Carolina bays and pocosins are considered in the Center’s scope of work.

Perspectives are derived from work on the southeastern Atlantic coastal plain, Mississippi alluvial valley, and northern Lake States.

Selected Publications

Disturbance Ecology

Natural and human disturbances effect forest development

Disturbances, whether natural such as fire and hurricane, or human such as silvicultural thinnings or regeneration cuts, have a significant effect on forest development since they change the vegetation composition and release growing space.

Hurricane Hugo (September, 1989) provided a significant opportunity to study the role of disturbances in determining forest structure and species composition.

A long-term cooperative project with Clemson University’s Belle Baruch Forest Ecology Center is monitoring the changes in forest composition and structure in five different cover types. Fire influences on plant community development following a hurricane is also be established in collaboration with Clemson University.

Selected Publications

Above-ground Productivity

Conducting field experiments related to high productivity for wetland tree species

Traits related to high productivity for wetland tree species grown on different site types are being identified.

Greenhouse experiments are being conducted to evaluate performance of fast growing bottomland hardwood species and to test the influence of hydroperiod on survival, above-and below-ground production, carbon allocation to structural and non-structural components, root adaptations to hypoxia, gas exchange, nutrient uptake, and nutrient cycling.

We are conducting field experiments in pine and hardwood stands supplied with a range of water and nutrient resources to evaluate processes controlling productivity.

Our main interest is in resource capture including light interception, water requirements and nutrient uptake. The main drivers of productivity are expected to be leaf area development and the amount of light absorbed by the canopy.

Soil resource availability and allocation of nutrients among above and belowground tissues will modify the level of light-driven production.

To evaluate changes in allocation, we are monitoring nutrient mass balance among the various tissues through periodic harvests. We are using the information gathered, including climate and soil conditions, to test predictive models of forest productivity.

Selected Publications

Below-ground Processes

Conducting studies of root processes and patterns of growth

The function of root processes in biomass production, and biogeochemical and water cycling is being studied in natural stands and plantations.

Studies involving in situ field measurement, destructive sampling, controlled mesocosm experiments and modeling are being conducted at the Center; specific aspects include belowground primary producivity, mortality, decomposition, patterns of growth phenology, and the dynamics of length and surface area.

In addition, the conversion of plant litter to soil organic matter along hydrologic and successional gradients, and carbon and nitrogen mineralization dynamics along hydrologic gradients are being studied. Research sites include the CBES and SRS.

Selected Publications