Hugh G. Hanlin

TL;DR: It is suggested that perceptions of herpetofaunal species diversity are strongly dependent on level of effort and that land management decisions based on short-term data bases for some faunal groups could result in serious errors in environmental management.

TL;DR: In this paper, the authors assessed and compared the richness, abundance, and diversity of herpetofauna at five small isolated wetlands (0.38-1.06-ha) imbedded within a commercial forest landscape in the South Carolina Coastal Plain.

Abstract: Forest managers in the Southeast increasingly need information about amphibian and reptile responses to silvicultural practices in order to guide sustainable forestry programs. A review of existing literature indicates that effects of silvicultural practices on herpetofauna often are regionand species-specific, with individual taxa responding positively, negatively, or not at all in the short term. Responses of herpetofauna to forestry likely are influenced by adaptations of taxa to historical disturbance regimes. Few studies have evaluated long-term population or landscape-level implications of silvicultural practices for herpetofauna. Furthermore, many existing studies lack pretreatment data, replication, or appropriate reference conditions. We suggest that future research focus on manipulative and retrospective studies designed to identify forestry practices that successfully blend economic objectives with herpetofaunal conservation. INTRODUCTION Forests of the Southeastern United States support a rich diversity of amphibians and reptiles (herpetofauna). Of the more than 450 species of herpetofauna native to North America, approximately half occur in the Southeast and roughly 20 percent, are endemic. Over 100 species (45 amphibians, 59 reptiles, excluding sea turtles) have been reported from the Coastal Plain of South Carolina alone (Zingmark 1978). Herpetofauna often are the most abundant vertebrates in forest ecosystems (Burton and Likens 1975, Congdon and others 1986); in the Southeast, they comprise up to 45 percent of vertebrate species, excluding fish (Vickers and others 1985). Several interrelated factors account for this regional herpetofaunal diversity, including tremendous variability in habitats related to a complex matrix of physiography and disturbance regimes (Sharitz and others 1992). Moreover many species of southeastern herpetofauna exhibit biphasic life histories, occupying both terrestrial and aquatic habitats during annual cycles (Gibbons and Semlitsch 1991). Increasingly, forest managers are challenged to balance production of forest products with maintenance of environmental quality, management of wildlife habitat, and conservation of biodiversity (Moore and Allen 1999, Sharitz and others 1992). Concerns about even-aged management, and particularly clearcutting, have prompted considerable research on effects of timber harvesting on wildlife. Most research has focused on mammals and birds, and other vertebrates such as amphibians and reptiles have received less attention (deMaynadier and Hunter 1995, Gibbons 1988, Moore and Allen 1999). 1 Assistant Professor of Wildlife Ecology and Management, University of Wisconsin – Stevens Point, College of Natural Resources, Stevens Point, WI 54481; Forest Wildlife Manager, National Council for Air and Stream Improvement, Inc., Clemson, SC 29634; Southern Region Wildlife Biologist, Westvaco Corporation, Summerville, SC 29484; Professor of Biology, University of South Carolina Aiken, Department of Biology and Geology, Aiken, SC 29801; Research Wildlife Biologist, U.S. Department of Agriculture Forest Service, Northeastern Research Station, Parsons, WV 26287, respectively. So ut he rn F or es t Sc ie nc e: Pa st , P re se nt , a nd F ut ur e Bi od iv er si ty 320 Despite their presumed role in forest food webs (Burton and Likens 1975, Congdon and others 1986), potential value as indicators of habitat quality (Dunson and others 1992), and controversy about global amphibian declines (e.g., Pechmann and others 1991), herpetofauna often are not fully considered in forest management decisions (deMaynadier and Hunter 1995). Questions about the compatibility of forestry and conservation of herpetofaunal biodiversity are driven largely by concerns that both terrestrial and aquatic habitats for many species may be degraded or eliminated in intensively managed forests. In particular, the permeable eggs, gills, and skin of amphibians make them potentially sensitive to changes in both aquatic and terrestrial habitats (Dunson and others 1992). To evaluate these concerns, deMaynadier and Hunter (1995) presented a comprehensive review of available literature about effects of forestry on North American amphibians. Several studies suggested that clearcutting and other forest management prescriptions had short-term impacts on some amphibians, especially salamanders. However, other work indicated that many species (1) were relatively insensitive to forest management, (2) recovered more rapidly after harvesting than previously thought, or (3) responded positively to forestry practices (deMaynadier and Hunter 1995). This literature review revealed that amphibian responses to forest management were complex and often specific to taxa or regions (deMaynadier and Hunter 1995). Since deMaynadier and Hunter’s (1995) review, additional studies have provided new insights about southeastern forestry and herpetofauna. Also deMaynadier and Hunter’s (1995) review did not address questions about reptiles, perhaps because of the focus on global amphibian declines (Gibbons and others 2000), or the historical perception that forestry impacts on reptiles generally were neutral or positive (Campbell and Christman 1982, Welsh and Lind 1991). Although evolutionary, morphological, behavioral, and ecological differences between amphibians and reptiles are substantial (Gibbons and others 2000), it is likely that these ectothermic tetrapods will continue to be considered collectively from both conservation and management perspectives (Gibbons and Stangel 1999, Gibbons and others 2000). The purpose of this chapter is to provide an up-to-date overview of information available about responses of amphibian and reptile populations to forestry practices in the Southeastern United States. OVERVIEW OF LITERATURE ON FORESTRY AND SOUTHEASTERN HERPETOFAUNA Harvesting and Silviculture P resumably the microclimatic, vegetational, and structural changes that occur after timber harvesting, and clearcutting in particular, create unsuitable conditions for moistureand temperature-sensitive amphibians. DeMaynadier and Hunter (1995) reviewed potential negative effects of harvesting on microhabitats correlated with amphibian species richness and abundance. Timber harvesting removes forest canopy, and so causes increased light penetration that results in higher soil temperatures and more evaporative loss of water from the soil and understory. Cover, in the form of leaf litter, coarse woody debris (CWD), and understory vegetation may be reduced following clearcutting and associated site preparation activities (Hunter 1990). Clearcut areas also are subject to greater daily fluctuations in temperature and humidity, and to increased soil surface disturbance during intensive harvest activities (deMaynadier and Hunter 1995). However, it has been suggested by several authors (e.g., Campbell and Christman 1982, Greenberg and others 1994, Welsh and Lind 1991) that clearcutting and other harvesting regimes often create favorable habitats for heliothermic reptiles adapted to early successional habitats. Amphibians—Several studies in hardwood forests of the Southern Appalachians appear to support the contention that changes in microhabitats and climate after clearcutting reduce amphibian diversity and abundance, with negative effects most pronounced on salamanders (Ash 1988, 1997; Buhlmann and others 1988; Ford and others 2002; Harpole and Haas 1999; Knapp and others 2003; Petranka and others 1993, 1994). In northern Georgia, stand age was an important factor explaining the abundance and community composition of plethodontid salamanders, e.g., Plethodon and Desmognathus spp., in cove hardwood communities (Ford and others 2002). In North Carolina, populations of plethodontid salamanders in recent clearcuts were 40 percent of those in undisturbed forested plots, and by the fourth year after harvesting, no salamanders could be found on clearcut sites (Ash 1988). Similarly Petranka and others (1993, 1994) found that plethodontid salamanders disappeared from Appalachian forests after clearcutting and that recovery to preharvest population levels took up to 60 years at high-elevation sites. Hyde and Simons (2001) also reported that effects of disturbance on the diversity and abundance of plethodontid 321 salamanders in the Great Smoky Mountains National Park were still evident after 60 years. Petranka and others (1993) hypothesized that during the last century, clearcutting reduced plethodontid salamander abundance by 70 percent in western North Carolina alone, with current harvest-related losses approaching 14 million salamanders per year. Three recent studies have evaluated effects of uneven-aged harvesting techniques on Appalachian salamanders. Harpole and Haas (1999) compared abundance of plethodontid salamanders before and after application of seven treatments (understory removal, group selection, two variants of shelterwood, leave tree, clearcutting, reference) in low-elevation hardwood forests in southwest Virginia. They found that salamander numbers were lower after harvesting on the group selection, leave tree, and clearcut sites, but no postharvest differences were detected during the same period on reference or understory removal sites. However, Ford and others (2000) detected no differences in abundance of plethodontid salamanders among group selection treatments, two-aged timber harvests, and uncut control stands in highelevation, Southern Appalachian hardwood forests of North Carolina. Bartman (1998) did not find that shelterwood harvesting affected salamander populations in the North Carolina Appalachians. Although it appears likely that diversity and abundance of plethodontid salamanders would decrease after clearcutting, Ash and Bruce (1994) and other authors (Ash 1997, Johnson and others 1993) argue that available data do not indicate that the long-term losses predicted by Petranka and others (1993, 1994) have occu

TL;DR: Responses of isolated wetland her petofauna to upland silviculture and the need for adjacent forested buffers likely depend on the specific landscape context in which the wetlands occur and composition of the resident herpetofaunal community.

TL;DR: Overall lower abundance and H′ values in the summers of 1994–1996 compared with 1977–1978 may be the result of habitat alteration during the restoration of the Carolina bay.