Herpetological Conservation and Biology 4(3):295-305. Submitted: 15 March 2008; Accepted: 9 September 2009 HABITAT ASSOCIATIONS OF REPTILE AND AMPHIBIAN COMMUNITIES IN LONGLEAF PINE HABITATS OF SOUTH MISSISSIPPI DANNA BAXLEY AND CARL QUALLS Department of Biological Sciences, The University of Southern Mississippi, 118 College Dr. #5018, Hattiesburg, Mississippi 39406, USA, e-mail: [email protected] Abstract.—Land managers and biologists do not yet thoroughly understand the habitat associations of herpetofauna native to longleaf pine forests in southern Mississippi. From 2004 to 2006, we surveyed the herpetofauna of 24 longleaf pine communities in 12 counties in south Mississippi. We quantified herpetofaunal diversity, relative abundance, and a suite of habitat variables for each site to address the following objectives: (1) determine what levels of habitat heterogeneity exist in longleaf pine forests in south Mississippi; (2) determine if reptile and amphibian community composition differs among these sites; and (3) if habitat-faunal differences exist among sites, identify what habitat variables are driving these community differences. Multivariate analysis identified three distinct longleaf pine habitat types, differing primarily in soil composition and percentage canopy cover of trees. Canonical correspondence analysis indicated that canopy cover, basal area, percentage grass in the understory, and soil composition (percentage sand, silt, and clay) were the predominant variables explaining community composition at these sites. Many species exhibited associations with some or all of these habitat variables. The significant influence of these habitat variables, especially basal area and canopy cover, upon herpetofaunal communities in south Mississippi indicates the importance of incorporating decreased stand density into management practices for longleaf pine habitat. Key Words.—amphibian; canopy cover; community; habitat associations; herpetofauna; longleaf pine; Mississippi; reptile INTRODUCTION al. 2007). To better define the faunal-habitat relationships of these communities, we addressed three The longleaf pine ecosystem, a landscape that once objectives: (1) determine what levels of habitat almost entirely characterized the southeastern coastal heterogeneity exist in longleaf pine forests in south plain of the United States (Stout and Marion 1993), has Mississippi; (2) determine if there are differences in been severely diminished (Ware et al. 1993). The reptile and amphibian community composition among reduction of longleaf pine forest to less than five percent these sites; and (3) if habitat-faunal differences exist of its historic range is largely due to fire suppression and among sites, identify what habitat variables are driving the conversion of longleaf pine forests to agricultural, these differences. silvicultural, or human use areas (Noss 1989; Frost 1993; Outcalt 1997; Varner and Kush 2004). Due to the MATERIALS AND METHODS elusive, fossorial, and often cryptic nature of many reptile and amphibian species, the community Study sites.—We primarily restricted the search for assemblages and habitat associations of herpetofauna suitable longleaf pine habitat to the southern, coastal native to longleaf pine forests in Mississippi are poorly plain region of Mississippi. The habitat in this study known. Guyer and Bailey (1993) described the consisted of sandy soils, with an over story of Longleaf unusually diverse herpetofauna of longleaf forests and Pine (Pinus palustris), a fire-maintained, herbaceous, estimated that about 72 reptile and amphibian species are grassy understory, and a fire-suppressed mid-story. We associated with this habitat, while one third of these identified and surveyed 24 sites with suitable habitat in species are endemics of the historic Longleaf Pine 12 counties (Fig. 1). Of these sites, 22 were on public (Pinus palustris) range. Although studies describing land and two were on private land. Of the public sites, reptile and amphibian communities in upland longleaf 17 were within the DeSoto National Forest (six within pine habitats are relatively common (Tuberville et al. the Chickasawhay District and 11 within the DeSoto 2005; Smith et al. 2006), most studies addressing District). We surveyed one site on the Mississippi habitat-faunal relationships within the longleaf pine Sandhill Crane National Wildlife Refuge, three sites ecosystem occurred in Florida and South Carolina (Dodd within the Marion County Wildlife Management Area, and Franz 1995; Yale et al. 1999; Litt et al. 2001). and one site owned by the Hancock County School Southern Mississippi contains a relatively under- Board. Additionally, several private landowners in both studied sector of longleaf pine forest and, to our Hancock County and George County allowed us to knowledge, there is only one published study concerning survey their lands. herpetofaunal communities within this area (Langford et 295 Baxley and Qualls.—Habitat associations with Mississippi herpetological communities FIGURE 1. Sites surveyed (red triangles) for reptiles and amphibians in Mississippi, USA from 2004–2006. Shaded areas represent public land (national forests or wildlife management areas). Survey techniques.—To address habitat variation as May) and 14 consecutive days in the summer (28 May – well as habitat/community associations of reptiles and 29 July). amphibians in Mississippi, we divided our project into We checked all arrays at least once per day, and, when two parts. In 2004, we surveyed all identified sites with temperatures exceeded 32° C, we checked traps twice standard herpetological sampling techniques including a per day. We removed all captured animals from traps combination of drift fences with pitfall and funnel traps and released them at the site of capture during each visit. (Gibbons and Semlitsch 1981; Campbell and Christman For each animal captured, we recorded the location, 1982; Fitch 1987), search and hand catch (Crump and date, and species. We collected habitat data at each Scott 1994), cover boards (Grant et al. 1992; Olson and sampling site during the first week of July 2004, 2005, Warner 2003), and road surveys (Dodd et al. 1989). Due and 2006. We then quantified and recorded the to time and budget constraints, we selected a subset of following habitat information: soil composition, the sites surveyed in 2004 for further surveys in 2005 dominant vegetation species, percent canopy cover of and 2006 (six sites), and we surveyed three sites in 2005 trees, percent mid-story coverage, percent shrub only (see Table 1 for number of survey years for each coverage, basal area of trees, percentage cover of site). In 2004, each 30.5 m drift fence contained four grasses, forbs, and shrubs in understory, ground-cover funnel traps and four pitfall traps (Fig. 2). To sample multiple sites within a local region simultaneously, we continuously deployed 12 or more drift fence/trap arrays. Cover boards and pit-fall use had low capture rates for species of interest in 2004, so we did not employ these techniques in 2005 or 2006. The number of drift fences erected at each site was proportional to the area of FIGURE 2. Drift fence array indicating the length and approximate suitable habitat present. Each year, we surveyed sites for placement of pitfall traps (circles) and placement of funnel traps > 14 consecutive days in the spring (15 March – 27 (triangles) at sites surveyed for herpetofauna in Mississippi, USA. 296 Herpetological Conservation and Biology TABLE 1. Sites surveyed for reptiles and amphibians in Mississippi, USA. Site numbers corresponding to map (Figure 1), property type, number of years surveyed, species richness, and habitat type for sites included in the PCA habitat analysis (O = open canopied group, M = moderate canopy closure group, and C = closed canopy group). Years Species Site County Property Type Habitat Type Surveyed Richness 1 Jones Desoto National Forest 3 20 C 2 Wayne Desoto National Forest 2 16 - 3 Wayne Desoto National Forest 3 20 C 4 Wayne Desoto National Forest 3 24 C 5 Wayne Desoto National Forest 3 29 C 6 Wayne Desoto National Forest 1 8 O 7 Greene Desoto National Forest 1 17 M 8 Marion Marion Co. Wildlife Management Area 1 10 - 9 Marion Marion Co. Wildlife Management Area 1 21 - 10 Marion Marion Co. Wildlife Management Area 1 15 - 11 Forrest Desoto National Forest 1 11 C 12 Forrest Desoto National Forest 1 14 M 13 Forrest Desoto National Forest 1 15 O 14 Perry Desoto National Forest 3 32 M 15 Forrest Desoto National Forest 1 7 C 16 Pearl River Desoto National Forest 1 10 C 17 Perry Desoto National Forest 1 13 M 18 Perry Desoto National Forest 1 15 O 19 George Private 1 11 M 20 Harrison Desoto National Forest 1 17 M 21 Harrison Desoto National Forest 1 8 M 22 Hancock Private 1 19 O 23 Hancock Private 1 16 M 24 Jackson Sandhill Crane National Wildlife Refuge 1 21 O percentage of litter and bare soil, and recency of fire. degree of habitat heterogeneity among survey sites, we We used a spherical densiometer (Forest Densiometers used principal components analysis (PCA) coupled with model-C, City, State, Country) to measure canopy cover analysis of similarity (ANOSIM) using the Bray Curtis (Dealy 1960). At each drift fence array, we took four similarity index (Bray and Curtis 1957). For this densiometer readings to estimate percentage canopy analysis, we included all sites surveyed in 2004 (20 cover facing north, south, east, and west of the array; we sites). To explicitly assess habitat associations of then