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Rebecca R. Sharitz

Publications and source records attributed to Rebecca R. Sharitz.

4 recordsLinked to original sources
USGS2009

The ecology, restoration, and management of southeastern floodplain ecosystems: A synthesis

Floodplain ecosystems of the southeastern United States provide numerous services to society, but hydrologic and geomorphic alterations, agricultural practices, water quality and availability, and urban development continue to challenge restorationists and managers at multiple spatial and temporal scales. These challenges are further exacerbated by tremendous uncertainty regarding climate and land use patterns and natural variability in these systems. The symposium from which the papers in 2009 ensued was organized to provide a critical evaluation of current natural resource restoration and management practices to support the sustainability of floodplain ecosystem functions in the southeastern United States. In this paper we synthesize these concepts and evaluate restoration and conservation techniques in light of our understanding of these ecosystems. We also discuss current and future challenges and attempt to identify new approaches that may facilitate the long-term sustainability of southeastern floodplain systems. We conclude that integration of disciplines and approaches is necessary to meet the floodplain conservation challenges of the coming century. Integration will not only include purposeful dialogue between interdisciplinary natural resource professionals, but it also is necessary to sincerely engage the public about goals, objectives, and desirable outcomes of floodplain ecosystem restoration.

Southeastern Floodplain systems↗
USGS1997

A comparison of wetland tree growth response to hydrologic regime in Louisiana and South Carolina

Numerous investigations have examined the growth of wetland tree species under a variety of hydrologic conditions. Most studies have compared flooded versus non-flooded conditions in greenhouses or in one to a few field sites near each other or within the same region. Comparisons of wetland tree growth among widely separated areas of the country are rare. This study compared the diameter growth of Nyssa sylvatica var. biflora, Nyssa aquatica , and Taxodium distichum trees from Louisiana (Gulf Coastal Plain) and South Carolina (Atlantic Coastal Plain). In both regions, individual trees were distributed along a gradient of hydrologic regimes from infrequent to permanent flooding. Nyssa sylvatica var. biflora was restricted to periodically flooded sites in both regions. Within these sites, this species showed little response to differences in mean water depth. In contrast, significant differences among hydrologic regimes were detected for N. aquatica in both regions. In Louisiana, patterns of growth response did not correlate with the gradient of hydrologic regimes, but in South Carolina maximum growth was inversely related to mean water levels during the growing season. Maximum growth of T. distichum trees was observed at sites with shallow, permanent flooding in both regions.

Louisiana, South Carolina↗
USGS1985

Disturbance in a cypress-tupelo wetland: an interaction between thermal loading and hydrology

The interaction between thermal loading and hydrology was examined in a forested wetland. As a result of flooding, portions of the wetland are periodically exposed to elevated water temperatures, resulting in progressive deterioration of the canopy. We chose three study sites along a gradient of canopy disturbance: most disturbed, intermediate disturbance and a least disturbed site. The timing of flooding has important effects on this wetland: floods which occur late in the growing season have greater impact on the timing of litterfall and the extent of tree mortality. Following a flood in May, there was no observed increase in litterfall, and woody detrital production (tree mortality) eliminated only o.4% and 1.1% of the aboveground woody biomass at the intermediate and least disturbed sites, respectively. In contrast. premature leaf senescence and literfall were observed at the intermediate site following an August flood, and tree mortality at the intermediate and least disturbed sites eliminated 10% and 8%, respectively, of the aboveground woody biomass. At the most disturbed site, where the majority of trees were already dead, no additional mortality was recorded during the study. Long-term effects of this disturbance regime are the loss of small stems and increased stem production of trees which remain. While stem production at the intermediate site (413 g.m −2 .yr −1 ) exceeded that at the least disturbed site (373 g.m −2 .y −1 ), total aboveground net primary production was highest at the least disturbed site (788 g·m −2 · yr −1 ), primarily because of the greater stem density. Portions of this wetland continue to deteriorate after more than 30 years of thermal loading.

Wetlands↗