Eric A. Nelson

Production of short-rotation woody crops grown with a range of nutrient and water availability: establishment report and first-year responses.

Coleman, M.D., et. al. 2003. Production of Short-Rotation Woody Crops Grown with a Range of Nutrient and Water Availability: Establishment Report and First-Year Responses. Report. USDA Forest Service, Savannah River, Aiken, SC. 26 pp. Abstract: Many researchers have studied the productivity potential of intensively managed forest plantations. However, we need to learn more about the effects of fundamental growth processes on forest productivity; especially the influence of aboveground and belowground resource acquisition and allocation. This report presents installation, establishment, and first-year results of four tree species (two cottonwood clones, sycamore, sweetgum, and loblolly pine) grown with fertilizer and irrigation treatments. At this early stage of development, irrigation and fertilization were additive only in cottonwood clone ST66 and sweetgum. Leaf area development was directly related to stem growth, but root production was not always consistent with shoot responses, suggesting that allocation of resources varies among treatments. We will evaluate the consequences of these early responses on resource availability in subsequent growing seasons. This information will be used to: (1) optimize fiber and bioenergy production; (2) understand carbon sequestration; and (3) develop innovative applications such as phytoremediation; municipal, industrial, and agricultural wastes management; and protection of soil, air, and water resources.

Selective depredation of planted hardwood seedlings by wild pigs in a wetland restoration area.

Abstract Following the planting of several thousand hardwood seedlings in a 69-ha wetland restoration area in west-central South Carolina, USA, wild pigs ( Sus scrofa ) depredated a large percentage of the young trees. This planting was undertaken as part of a mitigation effort to restore a bottomland hardwood community in the corridor and delta of a third order stream that had been previously impacted by the discharge of heated nuclear reactor effluent. The depredated restoration areas had been pretreated with both herbicide and control burning prior to planting the hardwood seedlings. After discovery of the wild pig damage, these areas were surveyed on foot to assess the magnitude of the depredation on the planted seedling crop. Foraging by the local wild pigs in the pretreatment areas selectively impacted only four of the nine hardwood species used in this restoration effort. Based on the surveys, the remaining five species did not appear to have been impacted at all. A variety of reasons could be used to explain this phenomenon. The pretreatment methodology is thought to have been the primary aspect of the restoration program that initially led the wild pigs to discover the planted seedlings. In addition, it is possible that a combination of other factors associated with odor and taste may have resulted in the selective depredation. Future wetland restoration efforts in areas with wild pigs should consider pretreatment methods and species to be planted. If pretreatment methods and species such as discussed in the present study must be used, then the prior removal of wild pigs from surrounding lands will help prevent depredations by this non-native species.

INFLUENCE OF A WILLOW CANOPY ON TREE SEEDLING ESTABLISHMENT FOR WETLAND RESTORATION

Black willow (Salix nigra) is a well-known pioneer species of disturbed riparian areas. It competes for nutrients, light, and water, but it may also act as a “nurse” crop, providing shelter for other species from high light and temperature; so, the overall effect on species planted under a willow canopy could be positive or negative. This experiment examined the response of container-grown seedlings of four tree species outplanted into three habitats: 1) an existing willow stand, 2) a similar habitat, but with the willow canopy removed, and 3) an adjacent grass-dominated area free of willow. After three years, survival rates of overcup oak (Quercus lyrata), baldcypress (Taxodium distichum), and water hickory (Carya aquatica) were not reduced under the willow canopy relative to the other two treatments. Laurel oak (Q. laurifolia) was killed by several floods during the first growing season. Height of baldcypress seedlings planted under a willow canopy was less than for seedlings where the willow had been removed. Water hickory and overcup oak height were not affected by the willow canopy. Elevation of the planting sites, indicating probable soil wetness, was a good indicator of survival when used in conjunction with the species flood-tolerance. The existing willow stand was not detrimental to survival of three of the outplanted tree species. Thus, willow removal is unnecessary for successful outplanting, saving time and money.

Operational restoration of the Pen Branch bottomland hardwood and swamp wetlands - the research setting

The Savannah River Swamp is a 3020 Ha forested wetland on the floodplain of the Savannah River and is located on the Department of Energys Savannah River Site (SRS) near Aiken, SC. Historically the swamp consisted of approximately 50 percent bald cypress-water tupelo stands, 40 percent mixed bottomland hardwood stands, and 10 percent shrub, marsh, and open water. Creek corridors were typical of Southeastern bottomland hardwood forests. The hydrology was controlled by flooding of the Savannah River and by flow from four creeks that drain into the swamp prior to flow into the Savannah River. Upstream dams have caused some alteration of the water levels and timing of flooding within the floodplain. Major impacts to the swamp hydrology occurred with the completion of the production reactors and one coal-fired powerhouse at the SRS in the early 1950s. Water was pumped from the Savannah River, through secondary heat exchangers of the reactors, and discharged into three of the tributary streams that flow into the swamp. Flow in one of the tributaries, Pen Branch, was typically 0.3 m3 s-1 (10-20) cfs prior to reactor pumping and 11.0 m3 s-1 (400 cfs) during pumping. This continued from 1954 to 1988 at various levels. The sustained increases in water volume resulted in overflow of the original stream banks and the creation of additional floodplains. Accompanying this was considerable erosion of the original stream corridor and deposition of a deep silt layer on the newly formed delta. Heated water was discharged directly into Pen Branch and water temperature in the stream often exceeded 65 degrees C. The nearly continuous flooding of the swamp, the thermal load of the water, and the heavy silting resulted in complete mortality of the original vegetation in large areas of the floodplain. In the years since pumping was reduced, early succession has begun in some affected areas. Most of this has been herbs, grasses, and shrubs. Areas that have seedlings are generally willow thickets that support a lower diversity of wildlife. No volunteer seedlings of heavy-seeded hardwoods or cypress have been found in the corridor areas. Research was conducted to determine methods to reintroduce tree species characteristic of more mature forested wetlands. Three restoration strategies were formulated to deal with the differing conditions of the Upper Corridor, the Lower Corridor, and the Delta regions of the impacted area. Site preparation and planting of each area with mixtures of tree species were carried out to speed the restoration of the ecosystem. Species composition and selection were altered based on the current and expected hydrological regimes that the reforestation areas will be experiencing. Because of the operational design of the restoration project, a research program naturally followed to document the success. Many of those efforts are detailed here.

Restoration of a severely impacted riparian wetland system - The Pen Branch Project

Development of an assessment framework and indicators can be used to evaluate effectiveness of wetland restoration. Example of these include index of biotic integrity and the hydrogeomorphic method. Both approaches provide qualitative ranks. We propose a new method based on the EPA wetland research program. Similar to other methods, indexes are compared to reference communities; however, the comparisons are quantitative. In this paper we discuss the results of our framework using the Pen Branch riparian wetland system as an example.

Locating delineated wetland boundaries in Coastal South Carolina using global positioning systems

A six-channel Global Positioning System was used to locate eleven points on wetland boundary lines. The latitude and longitude of these points were compared to locations obtained by a second order ground survey. Operating criteria and tree foliage coverage varied over a 19-month period of data collection (February 1992 to October 1993). Canopy coverage levels sampled within a hurricane impacted area, did not increase horizontal position error as much as percent of readings that had only 3 satellite (2D) coverage. If at least 60 readings were made at each point and more than 50% of the total readings had 4 satellite (3D) coverage, the average horizontal distance error was 3m. Beginning in June 1993, with appropriate adjustments in data collection and data manipulation, 5-m accuracy was obtained 95% of the time regardless of time of year, level of canopy coverage, or height of antenna. These accuracies seem to be sufficient for boundary surveys of delineated wetlands for routine regulatory purposes. Criteria for data collection should be specified so that the accuracy of the data can be evaluated.

The Pen Branch Project: Restoration of a Forested Wetland in South Carolina

T he Pen Branch Project is a program to restore a forested riparian wetland that has been subject to thermal diiturbance caused by nuclear reactor operations at the Department of Energy’s (DOE) Savannah River Site (SRS), an 80,200-hectare nuclear facility located inSouthCarolina. Various levels of thermal discharges to streams located across the US. have occurred and continue to occur as a result of nuclear operations, elecaicpowerptoduction, paper production, sewage treatment and other causes. Although thermal discharges occur, we are not aware of any other wetland restoration project implemented because of thermal Impacts, mainly because impacts from these various industries are hiily regulated and telatively minimal compared to the level of disturbance that has occurred in Pen Branch. Even though the functions that wetlands provide are widely acknowledged, losses continue at a rate of 47,000 hectares per year, much of which is occurring on forested wetlands in the SoutheastemUS. (Opheim, 1997). Techniques for restoring and monitoring bottomland forests, the major type of forested wetland in the Southeast, are undeveloped and imprecise (Clewell and Lea, 1990). InformatKon‘is needed to more effectively restore, conserve and manage these valuable ecosystems. The Pen Branch Project is designed to assess the effectiveness of a number of restoration techniques. Through comparisons of planted areas with unplanted control areas and comparisons among other bottomland ecosystems at different stages of succession, we will develop indicators of wetland health that will allow us to assess the effectiveness of future wetland restorations. Here we summarize the overall project and report on what has been accomplished to date.

United States Department of Agriculture Forest Service 1996 annual report wetlands research related to the Pen Branch restoration effort on the Savannah River site

This report documents the role of the USDA Forest Service and their collaborators (SRTC, SREL, and several universities) in wetlands monitoring and research on the Savannah River Site. This report describes the rationales, methods, and results (when available) of these studies and summarizes and integrates the available information through 1996.