Savannah River Ecology Laboratory Research Articles

An Effective Protocol for Proteome Analysis of Medaka (Oryzias latipes) after Acute Exposure to Ionizing Radiation

All terrestrial organisms are subject to evolutionary pressures associated with natural sources of ionizing radiation (IR). The legacy of human-induced IR associated with energy, weapons production, medicine, and research has changed the distribution and magnitude of these evolutionary pressures. To date, no study has systematically examined the effects of environmentally relevant doses of radiation exposure across an organismal proteome. This void in knowledge has been due, in part, to technological deficiencies that have hampered quantifiable environmentally relevant IR doses and sensitive detection of proteomic responses. Here, we describe a protocol that addresses both needs, combining quantifiable IR delivery with a reliable method to yield proteomic comparisons of control and irradiated Medaka fish. Exposures were conducted at the Savannah River Ecology Laboratory (SREL, in Aiken, SC), where fish were subsequently dissected into three tissue sets (carcasses, organs and intestines) and frozen until analysis. Tissue proteins were extracted, resolved by Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE), and each sample lane was divided into ten equal portions. Following in-gel tryptic digestion, peptides released from each gel portion were identified and quantified by Liquid Chromatography-Mass Spectrometry (LC-MS/MS) to obtain the most complete, comparative study to date of proteomic responses to environmentally relevant doses of IR. This method provides a simple approach for use in ongoing epidemiologic studies of chronic exposure to environmentally relevant levels of IR and should also serve well in physiological, developmental, and toxicological studies.

ESA Historical Records Committee Newsletter January 2019

ESA Historical Records Committee Newsletter January 2019

Competitive Sorption and Transport of Heavy Metals in Soils and Geological Media

Soil Science Society of America JournalVolume 77, Issue 6 p. 2216-2216 Book Review Competitive Sorption and Transport of Heavy Metals in Soils and Geological Media John C. Seaman, Corresponding Author John C. Seaman seaman@srel.uga.edu Savannah River Ecology Laboratory, The University of Georgia, Drawer E, Aiken, SC, 29802Corresponding author (seaman@srel.uga.edu)Search for more papers by this author John C. Seaman, Corresponding Author John C. Seaman seaman@srel.uga.edu Savannah River Ecology Laboratory, The University of Georgia, Drawer E, Aiken, SC, 29802Corresponding author (seaman@srel.uga.edu)Search for more papers by this author First published: 07 November 2013 https://doi.org/10.2136/sssaj2013.0004br All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permission for printing and for reprinting the material contained herein has been obtained by the publisher. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume77, Issue6November-December 2013Pages 2216-2216 RelatedInformation

How Frequently Do Cottonmouths (Agkistrodon piscivorus) Bask in Trees?

A common belief in the southeastern United States is that Cottonmouths (Agkistrodon piscivorus) bask frequently in tree branches over the water's edge and are therefore of considerable hazard for anglers and boaters. Although this notion is almost certainly based upon observations of nonvenomous watersnakes (Nerodia spp.), there are no quantitative data that specifically address this belief. I analyzed a 7-yr dataset on Cottonmouths from two populations (Georgia and Alabama) to determine the frequency of this behavior by Cottonmouths. I recorded behavioral and substrate information for 804 separate observations on Cottonmouths. Only two of these Cottonmouths were exhibiting arboreal behavior (0.25% of observations)—snakes observed over the ground or water surface on branches narrower than their own bodies—confirming that this is indeed a very rare tendency in this species and not likely to be observed by the public. Instead, I frequently encountered Cottonmouths on the ground along the water's edge in their characteristic ambush posture, uncoiled in aquatic situations, or coiled on elevated platforms (e.g., hummocks, piles of driftwood, logs, beaver lodges). This demonstrates that Cottonmouths have the capacity to climb but are not likely to be observed in arboreal situations. Few snakes in North America are as easily observed, frequently encountered, and misunderstood by the public as Cottonmouths (Agkistrodon piscivorus). Previous research has demonstrated that anecdotal accounts of aggressive behavior in this species—widely believed by the general public throughout the range of this snake—are unfounded (Gibbons and Dorcas, 2002; Glaudas, 2004; but see Means, 2010). Although factual information is becoming available through television and internet media, additional research is necessary to dispel myths regarding this and other snake species. Another widespread belief common in the Southeast is that Cottonmouths bask in the branches of trees and shrubs at the water's edge and often fall on hapless boaters. This belief has been articulated to J. W. Gibbons (Savannah River Ecology Laboratory, pers. comm.), J. B. Jensen (Georgia Department of Natural Resources, pers. comm.), C. Guyer (Auburn University, pers. comm.), and myself (pers. obs.). Although this belief is most likely a myth based upon encounters or stories involving misidentified watersnakes, there are currently no published data that refute the assertion that Cottonmouths bask in trees. Moreover, while several reviews of Cottonmouth natural history suggest that this species is generally found at the water's edge, floating on water, or lying on terrestrial substrates (Gloyd and Conant, 1990; Campbell and Lamar, 2004; Ernst and Ernst, 2004; Gibbons and Dorcas, 2005), these sources also mention that Cottonmouths are occasionally observed in trees and shrubs near the water's edge. These assertions are based largely on anecdotal observations and could be misinterpreted by lay readers who frequently misidentify watersnakes (Nerodia spp.) as Cottonmouths (Gibbons and Dorcas, 2004), which frequently bask from such perches (Tiebout and Cary, 1987; Gibbons and Dorcas, 2004). To date, no quantitative comparison of arboreal versus terrestrial (or aquatic) tendencies in the Cottonmouth is available. Reports of other terrestrial pit vipers exhibiting surprisingly arboreal feats (e.g., Timber Rattlesnake, Crotalus horridus; Coupe, 2001, Rudolph et al., 2004) further indicate the need for accurate information about Cottonmouths. To determine the frequency that observers might expect to find Cottonmouths basking above the water surface in vegetation, I analyzed my own observations of 804 encounters with Cottonmouths during 2003-09 from sites in Georgia and Alabama. I analyzed the frequency with which I found Cottonmouths in arboreal, aquatic, or elevated substrates and the behaviors they were exhibiting from these positions.

A Long-Term Perspective of Delayed Emergence (aka Overwintering) in Hatchling Turtles: Some They Do and Some They Don't, and Some You Just Can't Tell

Abstract I re-examine the phenomenon of delayed timing of emergence from the nest by hatchling turtles (known as overwintering in temperate climates) within the context of the original summary of the topic in an article by Gibbons and Nelson in 1978. I base the overview on cumulative data from research at the Savannah River Ecology Laboratory since 1968 and reports from other locations during the past 34 yr. Investigators have reported known or suspected delayed emergence of hatchling turtles for 43 species, 22 genera, and 8 families from 11 countries and 36 U.S. states and Canadian provinces. The following perspective suggests questions to address and provides recommendations for how herpetologists should proceed in further investigating the phenomenon of hatchling emergence in turtles. The topic is one on which answers must be forthcoming to address turtle conservation on a global scale. For freshwater turtles, which include the majority of the world's turtles, natural selection has favored hatchlings t...

Exposure to low level chronic radiation leads to adaptation to a subsequent acute X-ray dose and communication of modified acute X-ray induced bystander signals in medaka (Japanese rice fish, Oryzias latipes)

Purpose: To determine the effect of acute high dose X-rays on the direct and bystander response of chronically exposed medaka in vivo using the fish communication model.Methods: Medaka were obtained from the Low Dose Rate Irradiation Facility (LoDIF) located at the Savannah River Ecology Laboratory (SREL), University of Georgia, Aiken, South Carolina, USA where they had been exposed over 264 days to cumulative total doses of 0, 0.03, 0.66 and 5.88 Gy. They were exposed to the acute dose at McMaster University and then allowed to swim with unexposed medaka. All groups were sacrificed and fins were cultured as explants and assayed using an established technique and reporter assay.Results: Directly irradiated medaka with no chronic exposure showed a classic in vivo bystander response. Chronic pre-exposure resulted in a chronic dose-dependent increase in reporter cell survival in directly exposed fish. A ‘pro-survival’ response was also seen in the bystander fish. The proteins bcl-2 (b cell lymphoma 2) and c-Myc (myelocytomatosis oncogene cellular) in tissue explants were good predictors of pro-life or pro-death signals.Conclusions: Environmentally relevant chronic exposure to medaka in vivo results in adaptive responses in fish subsequently irradiated with high acute doses and in communication of protective signals to fish swimming with exposed fish. The data have implications for interpretation of radiation effects in biota.

Hematology of the Pascagoula Map Turtle (Graptemys Gibbonsi) and the Southeast Asian Box Turtle (Cuora amboinensis)

Turtle populations are decreasing dramatically due to habitat loss and collection for the food and pet market. This study sought to determine hematologic values in two species of turtles to help assess health status of captive and wild populations. Blood samples were collected from 12 individuals of the Pascagoula map turtle (Graptemys gibbonsi) and seven individuals of the southeast Asian box turtle (Cuora amboinensis) from the Savannah River Ecology Laboratory (South Carolina, USA). The hematologic data included hematocrit, total solids, erythrocyte count, leukocyte count, and differential and percentage leukocyte counts. Low hematocrit values and high basophil counts were found in both species. The basophil was the most abundant leukocyte in the Pascagoula map turtle (median = 0.80 x 10(9)/L), whereas in the Southeast Asian box turtle the most abundant leukocyte was the heterophil (median = 2.06 x 10(9)/L).

Wood Stork Nesting in Georgia: 1992-2005

Wood Storks (Mycteria americana) were first recorded nesting in Georgia in 1965 at Blackbeard Island National Wildlife Refuge (Harris 1995). In 1992, biologists initiated annual aerial surveys of known wading bird rookery sites to document Wood Stork distribution and estimate the number of nesting pairs in Georgia. Additionally, personnel from the U.S Fish and Wildlife Service and Savannah River Ecology Laboratory have contributed annual ground-count data for several colonies. Since surveys began, stork nesting has been documented at least once in 43 locations across the Coastal Plain of the state, with an average of 14 active sites per year. The documented nesting effort for storks has increased from four pairs in one wading bird colony in 1965 to a high count of 1,817 pairs in 19 colonies in 2005. A regression of log-transformed nest totals for the 14-year time-series (1992-2005) showed no significant overall trend in nesting pair numbers (P = 0.84) for that period. However, it is possible that an ongoing rebound from a drought-related crash could continue, resulting in an increasing trend. Thirty-three (77%) of stork nesting locations were on private land, with only ten (23%) nesting locations in public ownership. Seven colony sites have supported an average of 68% of the stork nesting effort since 1992; in 2005 these sites supported 77% of the nesting effort. Although not a systematic census of all potential stork nesting habitat, these standardized surveys have produced a useful estimate of Wood Stork population size, distribution, and stability in Georgia. We believe that Georgia’s Wood Stork population has shown an increase in size and distribution, and that numbers can continue to increase or stabilize as long as hydrologic conditions favorable to the species persist.

Ecologists and the experimental landscape: the nature of science at the US Department of Energy's Savannah River Site

Although ecological conceptions of nature remain among the most authoritative in the world today, cultural geographers of landscape have paid little attention to the continuing salience of landscape as an object and scale of analysis in landscape and ecosystems ecology. That this object — a naturalized landscape of dynamic and multi-scalar systems and flows, not fixity — has been constructed, disproportionately, from some of the most technological of spaces, compels us to look more closely at the ways that specific natures circulate to inform general principles and ideas. This article explores how ecologists and other environmental scientists have turned the buffer zone surrounding the US Department of Energy's Savannah River Site, a former plutonium and tritium production plant, into an experimental landscape, with all the proprietary qualities embodied in the latter term. The study brings together a genealogy of the site as a space for scientific ecology with interviews conducted with contemporary environmental scientists based there, focusing chiefly on the work of scientists at the Savannah River Ecology Laboratory. By investigating the nature of agency, institution building, and representational practices in the making of an experimental, ecological landscape, the article also raises questions about how, at the Savannah River Site and elsewhere, the work of environmental science relates to the productive processes going on around it.

Savannah River Lab to Close After DOE Cuts Its Funding

Budget cuts have U.S. ecologists preparing for the demise of the Savannah River Ecology Laboratory and the potential layoffs of its 100-member staff, 10 of whom are faculty members at the University of Georgia, which operates the facility. (Read more.)

John C. Avise — Recipient of 2006 Molecular Ecology Prize

John C. Avise — Recipient of 2006 Molecular Ecology Prize

Effects of dominant species on vegetation change in Carolina bay wetlands following a multi-year drought1

Abstract Mulhouse, J. M. (University of Georgia, Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802), D. De Steven (USDA Forest Service, Southern Research Station, Center for Bottomland Hardwoods Research, P.O. Box 227, Stoneville, MS 38776), R. F. Lide (Northwest Florida Water Management District, 81 Water Management Dr., Havana, FL, 32333), and R. R. Sharitz (University of Georgia, Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802). Effects of dominant species on vegetation change in Carolina bay wetlands following a multi-year drought. J. Torrey Bot. Soc. 132: 411–420. 2005.—Wetland vegetation is strongly dependent upon climate-influenced hydrologic conditions, and plant composition responds in generally consistent ways to droughts. However, the extent of species composition change during drought may be influenced by the pre-existing structure of wetland vegetation. We characterized the vegetation of ten herbaceous Carolina bay wetlands on the South Carolina Upper Coastal Plain dur...

A Lease on Life for SREL?

If the House of Representatives has its way, the Savannah River Ecology Laboratory (SREL) will have a bit more time to fight a White House plan to shutter it. Under that proposal, the $8-million-a-year lab would close on 30 September. Although the measure failed to provide new funds for the lab for

NATURE'S TINIEST GEOENGINEERS

HISTORICALLY, GEOCHEMICAL processes were thought to be largely, if not entirely, driven by abiotic chemical reactions. People ignored what bacterial metabolism might be contributing, noted Andrew L. Neal, a geomicrobiologist at the University of Georgia's Savannah River Ecology Laboratory. But now we know that many important geochemical reactions are driven by bacteria. The relationship between microorganisms and geochemistry was the subject of a symposium held last month at the American Chemical Society national meeting in New York City. The symposium was cosponsored by the Geochemistry, Environmental Chemistry, and Biological Chemistry Divisions. And it was co-organized by Neal and Craig Cooper, a geochemist at the Idaho National Engineering & Environmental Laboratory (INEEL). Bacteria and other microbes impact just about every geochemical process that one can think of, including the weathering of rocks, the fate of metal-based contaminants in streams and rivers, and the formation and disappearance ...

Ground Layer Competition and Herbivory Effects on Cherrybark Oak (Quercus pagoda Raf.) Regeneration in Experimental Canopy Gaps

COLLINS, BEVERLY (Savannah River Ecology Laboratory, Aiken, SC 29802). Ground layer competition and herbivory effects on cherrybark oak (Quercus pagoda Raf.) regeneration in experimental canopy gaps. J. Torrey Bot. Soc. 130:147-157. 2003. -Windthrows and small-scale forest harvests generate environmental heterogeneity and dense regrowth. In such sites, interactions among environmental factors, competition with ground layer vegetation, and herbivores attracted to the disturbed area all potentially influence recruitment and early establishment of canopy tree species. I examined the interactive effects of overstory gap size, canopy openness, herb layer competition, and mammalian (deer, swamp rabbits) herbivory on emergence and seedling bank formation of cherrybark oak, Quercus pagoda Raf., in experimental gaps created by mechanized logging in a bottomland hardwood forest. Acorns were planted in exclosures (deer, swamp rabbits, deer + swamp rabbits, neither) in the center of three gaps of each of six gap sizes (7, 10, 14, 20, 29, 40 m radius) and outside the exclosures in center, edge, and forest positions. Mortality was greatest during recruitment (within the first season), and was due primarily to damage to acorns by seed predators and shade effects on seedling establishment. After three seasons, seedlings from damaged acorns in the exclosure plots were shorter than those from undamaged acorns; however, these seedlings had higher relative growth rate, which suggests that acorn damage effects decline over time. Herb layer competition and shade due to position within a gap or gap size were associated with reduced survival or height of seedlings, both in the exclosures and in center, edge, and forest positions. Deer or rabbit herbivory had no measurable effect on seedling survival or growth over the first three seasons. Natural or created canopy gaps ' 14 m radius can be foci for Q. pagoda regeneration if acorns are protected from predators; however, the dense vegetation in regenerating gaps could limit seedling height growth and multiple openings may be necessary for ascent out of the seedling bank.

Applications of synchrotron-based X-ray microprobes.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTApplications of Synchrotron-Based X-ray MicroprobesPaul M. Bertsch and Douglas B. HunterView Author Information Advanced Analytical Center for Environmental Sciences, Savannah River Ecology Laboratory, The University of Georgia, Drawer E, Aiken, South Carolina 29802 Cite this: Chem. Rev. 2001, 101, 6, 1809–1842Publication Date (Web):June 13, 2001Publication History Received20 September 2000Published online13 June 2001Published inissue 1 June 2001https://doi.org/10.1021/cr990070sCopyright © 2001 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views1579Altmetric-Citations132LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (2 MB) Get e-AlertsSUBJECTS:Elements,Energy,Microscopy,Minerals,X-rays Get e-Alerts

Mass Allocation and Self-Burial of Aristida tuberculosa Florets

COLLINS, B. S. AND G. R. WEIN (Savannah River Ecology Laboratory, Aiken, SC 29802). Mass allocation and self-burial of Aristida tuberculosa florets. J. Torrey Bot. Soc. 124:306-311. 1997.-Aristida tuberculosa is an annual grass of impoverished old fields on the southeastern coastal plain. Mature florets have hygroscopic awns and self-bury; florets that do not implant usually do not germinate, or seedlings fail to establish. We examined the influence of soil fertility on mass allocation in Aristida plants and florets, and the consequences of relative investment in caryopsis and awn for self-burial on litter and bare substrate. In the greenhouse, soil fertility did not influence mean per-floret mass or awn length, but fertilized plant florets had lighter caryopses and greater relative investment in awn than unfertilized plant florets. In field-collected propagules, caryopsis mass and awn length were inversely related to soil fertility; mean per-floret mass and relative investment in awn and caryopsis did not differ among fields. Relative investment in awn and caryopsis did not influence floret burial in field or greenhouse trials. Litter cover did enhance burial in both the field and the greenhouse; florets buried deeper in the heavier litter of the most fertile field site. We conclude that, although soil fertility influences floret biomass allocation in Aristida, relative allocation to awn and caryopsis does not influence floret performance.

When is a Depression Wetland a Carolina Bay?

90Southeastern Geographer Lowrance, R., Sharpe, J. K., and Sheridan, J. M. 1986. "Long-Term Sediment Deposition in the Riparian Zone ofa Coastal Plain Watershed," Journal ofSoil and Water Conservation , Vol. 41, pp. 266-271. Lowrance, R., Mclntire, S., and Lance, C. 1988. "Erosion and Sediment Deposition in a Field-Forest System Estimated using Cesium- 137," Journal ofSoil and Water Conservation , Vol. 43, pp. 195-199. Markewich, H. W., Pavich, M. J., and Buell, G. R. 1990. "Contrasting Soils and Landscapes of the Piedmont and Coastal Plain, Eastern United States," Geomorphology, Vol. 3, pp. 417-448. NCDEM (North Carolina Division of Environmental Management). 1994 et seq. TarPamlico River Basinwide Water Quality Management Plan (Raleigh, NC: Division of Environmental Management). Phillips, J. D. 1993. "Pre- and Post-Colonial Sediment Sources and Storage in the lower Neuse River basin, North Carolina," Physical Geography, Vol. 14, pp. 272-284. Phillips, J. D., Wyrick, M. J., Robbins, J. G., and Flynn, M. 1993. "Accelerated Erosion on the North Carolina Coastal Plain," Physical Geography, Vol. 14, pp. 1 14-130. SCS (Soil Conservation Service). 1985. Haw River Erosion Report. Deep River Erosion Report (Raleigh, NC: United States Department of Agriculture). SCS (Soil Conservation Service). 1989. Soil Survey of Craven County, North Carolina (Raleigh, NC: United States Department of Agriculture). Slattery, M. C, Burt, T. P., and Boardman, J. B. 1 994. "Rill Erosion along the Thalweg ofa Hillslope Hollow: A Case Study from the Cotswold Hills, Central England," Earth Surface Processes and Landforms, Vol. 19, pp. 377-385. Trimble, S. W. 1974. Man-Induced Soil Erosion in the Southern Piedmont, 1700-1970 (Ankeny, IA: Soil Conservation Society of America). Southeastern Geographer Vol. XXXVII, No. I, May 1997, pp. 90-98 WHEN IS A DEPRESSION WETLAND A CAROLINA BAY?1 Robert F. Lide Are sites such as those shown in Figures 1 and 2 the same type of geomorphic feature? Does the term "Carolina bay" have a specific geomorphological definition , or is it simply a colloquial term that may be used to describe any depression wetland found on the southeastern Atlantic Coastal Plain? The purpose ofthis research note is: (1) to illustrate that, despite a seemingly precise definition, the term "Carolina bay" often is loosely applied in the scientific literature and (2) to Mr. Lide is a research technician at the Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802. VOL. XXXVII, NO. 1 91 argue that the term should be limited to geomorphic features that have a more or less elliptical, ovate, or circular outline. Carolina bays are a common type of depression wetland found on the Atlantic Coastal Plain of the southeastern United States (Fig. 3). Their size is highly variable , ranging from 50 meters in length to 8 kilometers (Sharitz and Gibbons, 1982). Although generally characterized by internal drainage, many have natural overflow outlets that may allow the establishment of temporary connections to stream and drainage networks during wet periods. Some Carolina bays form the headwaters of perennial streams, and a few have small creeks flowing into them. These wetlands increasingly are recognized as critical habitat for the maintenance of biodiversity. In recent years, many have been the subject of wetland preservation and restoration efforts. Historically, Carolina bays have been defined in the scientific literature by several specific geomorphological criteria: (1) being elliptical, ovate, or circular; (2) having a long-axis orientation that usually is northwest-southeast; and (3) often having a sand rim that is best developed along the eastern and southeastern perimeter (e.g., Melton and Schriever, 1933; Johnson, 1942; Prouty, 1952; Price, 1968; Savage, 1982). Many sites meet these geomorphological criteria (Fig. 1). In recent years, however, some published reports have used the term "Carolina bay" loosely to include coastal plain wetlands that lack some or all ofthese specific criteria (e.g., Norris, 1963; Pechmann et al., 1989; Schalles et al., 1989; Gibbons, 1 990; Mahoney, Mort, and Taylor, 1 990; Newman and Schalles, 1 990; Pechmann et al., 1991). Furthermore, wetlands with highly irregular outlines sometimes are identified as "Carolina bays" (Fig. 2). Although a few notes about circular or elliptical "bays" were recorded by early scientists (e.g., Tourney, 1848; Glenn, 1895), modern scientific investigation of Carolina bays began...

Age Structure and Possible Origins of Old Pinus taeda Stands in a Floodplain Forest

PEDERSON, N. A. (School of Forestry, Auburn University, AL 36849), R. H. JONES (Department of Biology, Virginia Tech, Blacksburg, VA 24061), AND R. R. SHARITZ (Savannah River Ecology Laboratory, Aiken, SC 19802 and Department of Botany, University of Georgia, Athens GA 30602). J. Torrey Bot. Soc. 124:111-123. 1997.-Stand structure and ages were measured in six old stands of Pinus taeda L. (loblolly pine) and one younger stand within Congaree Swamp National Monument, South Carolina. Dominant overstory species included loblolly pine, shade intolerant hardwoods and tolerant hardwoods. All overstory species except pine also occurred in the sapling layer. Five of the six old stands had two or more pine age classes. All but one individual pine was less than 200 years old. According to estimates of future survival, current loblolly pine seedling densities in recently hurricane-disturbed and clearcut areas are inadequate to reproduce tree densities measured in extant old stands. Spatial distributions of mature trees suggest that pines have established in gaps as large as 0.3 ha and as small as a single overstory tree. No evidence of fire (scars on existing trees or charcoal in the upper 10 cm of soil) was found in any old stand. From these results, we speculate that the old loblolly pine stands in Congaree Swamp resulted from small-scale agricultural activities, although wind storms, fires, or combinations of these may have played contributing roles. Because of its apparent ability to regenerate in gaps, loblolly pine will probably remain in Congaree Swamp for several centuries as small clumps and scattered individuals.

Hurricane Impacts on Liana Populations in an Old-Growth Southeastern Bottomland Forest

ALLEN, B. P. (Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802), E. F. PAULEY (Department of Biology, Coastal Carolina University, Conway, SC 29528), AND R. R. SHARITZ (Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802). J. Torrey Bot. Soc. 124: 34-42. 1997.-Old-growth bottomland hardwood and slough forests of the Congaree Swamp National Monument, Columbia, SC, were exposed to winds of up to 155 km/hr during Hurricane Hugo in September 1989. Liana distribution and population changes were examined in ten 1 ha plots in 1989-90 and 1994. Prior to the hurricane, vines were not randomly distributed among host tree species. In the bottomland hardwood communities, Liquidambar styraciflua L. and Fraxinus spp. supported relatively more vines, and Ilex spp., Carpinus caroliniana Walter., and Nyssa spp. had fewer vines than other tree species. Liquidambar styraciflua was more likely to host Rhus radicans than were other tree species. Small trees with lianas suffered disproportionally greater damage from the hurricane than small trees with no lianas; trees of all sizes that supported three or more lianas were more likely to be damaged. Declines in liana populations appear to be related to high tree damage and to hydrologic regime. In sloughs, declines in liana stem density were greater than the levels of canopy damage would predict. Large woody vines that survived grew slowly over the four years following the hurricane.