Influence of Ecosystem Restoration for Red-Cockaded Woodpeckers on Breeding Bird and Small Mammal Communities
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Influence of Ecosystem Restoration for Red-cockaded Woodpeckers on Breeding Bird and Small Mammal Communities Ronald E. Masters1, Christopher W. Wilson2, Douglas S. Cram1, George A. Bukenhofer3 and Robert L. Lochmiller4 Abstract.—Shortleaf pine-bluestem (Pinus echinata Mill.- midstory and some codominant pine and hardwood Andropogon spp.) restoration for red-cockaded trees in 1979. This cultural practice, wildlife stand woodpeckers (Picoides borealis) has been underway for improvement (WSI), is followed by dormant-season more than 2 decades on the Ouachita National Forest, prescribed fire every 3 years (U.S.D.A. 1985). In the Arkansas. Restoration efforts consist of modifying stand early 1990s, application of these practices was structure to basal areas similar to presettlement times broadened to an ecosystem approach for restoration of and reintroduction of fire. This is accomplished through the shortleaf pine- bluestem (Andropogon spp.) midstory and codominant tree removal (wildlife stand community on the Ouachita National Forest. improvement -WSI) and dormant season prescribed fires on a 3-year cycle. Concern has been expressed about the For landscape and ecosystem restoration, quantitative influence of this type of management on non-target knowledge of historical vegetation patterns across the species, specifically small mammals and breeding birds. landscape is essential in order to develop suitable Control stands (no thinning or fire) were characterized restoration targets. Historical land use documents such by closed canopies and dense midstory with little as General Land Office (GLO) survey notes have understory vegetation. WSI-treated stands were successfully been used to describe presettlement and characterized by open canopies, little midstory and an settlement landscapes (Cottam 1949, Lorimer 1980, Foti increase in herbage production by 3-7 fold depending and Glenn 1991). Analysis of GLO data in the Ouachita on whether or not stands had been burned and time Highlands of Arkansas (Foti and Glenn 1991) and later since the stands had been burned. Woody cover after in Oklahoma (Kreiter 1995) provided targets for stem WSI followed a predictable increase with additional density, basal area and information on tree species growing seasons since prescribed fire. Total community composition for renewal of the pine-bluestem abundance, species richness, and diversity of small community. mammal and breeding bird communities were dramatically increased by restoration. No small Birds and small mammals have often been used as mammal species were adversely affected by restoration representative taxa to determine vertebrate wildlife treatments. Pine-grassland obligate songbirds increased responses to forest management practices (Morrison following WSI and many of these showed significant 1992, Masters et al. 1998). Bird distribution and increases directly attributable to fire. Bird and small abundance is largely determined by vegetation structure mammal habitat associations are also described. (MacArthur and MacArthur 1961; Wiens 1974; Roth 1976) and plant species composition (Smith 1977; Rice Introduction et al. 1983; Brennan and Morrison 1991). As well, habitat suitability for small mammals may be altered by Shortleaf pine (Pinus echinata Mill.) -grassland habitats forest management practices that modify primary were once a prevalent landscape component in the production or vegetation structure (Masters et al. 1998). Ouachita Mountains (Nuttall 1980; Foti and Glenn 1991; Masters et al. 1995). Frequent fire maintained The relationship between habitat attributes and bird these woodlands as distinctly open, pine-dominated species richness and abundance has been demonstrated communities (Jansma and Jansma 1991; Masters et al. in a number of forest types (e.g., Karr and Roth 1971; 1995). Fire suppression has led to the replacement of Willson 1974; James and Wamer 1982; Yahner 1986) pine-grassland woodlands with closed canopy pine- and also for many small mammals (e.g., Dueser and hardwood forest types throughout the southeastern Shugart 1978; Grant and French 1980; Root et al. 1990; United States (Waldrop et al. 1992). To improve habitat Tappe et al. 1994). While several studies have examined conditions for the endangered red-cockaded bird and small mammal-habitat relations following fire, woodpecker (see list of common and scientific names none we are aware of have sought to determine for bird species), the U. S. Forest Service began thinning population response and habitat characteristics important to bird or small mammal species in restored fire-dependent pine-grassland communities other than Wilson et al. (1995) and Masters et al. (1998). 1Department of Forestry, Oklahoma State University, Stillwater, OK Pine-grassland restoration alters plant community 2The Nature Conservancy, Tulsa Oklahoma 74114 structure and composition that ultimately affect the breeding bird and small mammal communities. Public 3 USDA Forest Service, Atlanta, GA 30309 concern has arisen over the impacts of management for 4Deceased The role of fire in nongame wildlife management and community restoration: traditional uses and new directions GTR-NE-288 73 a single species on other members of the vertebrate Bird and Small Mammal Surveys community. Detailed information on population We quantified relative bird abundance in 1992 and response and habitat relations in fire-dependent 1993, using 6, 40-m-radius point count plots 130-150 woodlands is necessary to accurately assess the impacts m apart with >90 m between plot centers and stand of WSI and prescribed fire in woodland restoration and boundaries within each stand (Hutto et al. 1986). to determine relative success of efforts. Because Methods, abundance, and frequency data were reported restoration efforts have been underway for a relatively in Wilson et al. (1995). In 1999 and 2000, we followed short period of time, the plant community may be in a the same methodology except that we sampled 3-point state of transition as additional burning cycles are count plots in each stand. Analysis of previous years accomplished and as the extent of restored stands data demonstrated that 3 bird plots adequately increases. Therefore we followed up on our initial efforts characterized birds of greatest interest and the most (Wilson et al. 1995) to assess the breeding bird abundant birds in the community. community. Our objectives were to document relative abundance in untreated and treated stands and to We quantified small mammals using live traps and determine plant community structural and mark-recapture techniques in winter 1992 and 1993 (27 compositional attributes that best explained breeding Dec - 4 Jan). We located 80 Sherman live-traps at 15 m bird and small mammal abundance. intervals on randomly located parallel transect lines within each stand. Methods, abundance and trap-nights Materials and Methods of effort were reported by Masters et al. (1998). Study Area Vegetation Composition and Structure Our study stands were within a >60,000-ha area We measured woody species composition and forest proposed for pine-bluestem restoration in the west- structure in 4 circular, 5-m radius subplots within each central Ouachita Mountains in the Poteau, Mena, and bird point count plot from late May to early June, 1992 Cold Springs Ranger districts of the Ouachita National and 1993 to examine habitat relationships. The first Forest, Scott County, Arkansas. Topography was subplot was located at bird point count plot center. The mountainous with numerous east-west trending ridges second subplot was placed in a random direction, 30 m and valleys. We initially focused on pine-bluestem from point count plot center. The remaining 2 subplots restoration stands with active woodpecker clusters or were placed 120o and 240o from the second, and 30 m evidence of past woodpecker occupation in the vicinity from point count plot center. (Neal and Montague 1991), but restoration efforts have now expanded outside of previously known cluster sites. We determined shrub density by counting all woody All stands consisted of second-growth forest with a stems 0.5-1.4 m in height within each subplot. We history of timber management and ranged in size from categorized stems >1.4 m in height into 8 diameter 14-61 ha. The study area was previously described by classes. We recorded all trees, shrubs, and vines within Wilson et al. (1995) and Masters et al. (1996). each subplot by species. We used a 10-factor prism to estimate conifer and hardwood BA in all years (Avery Experimental Design 1967) at the center of each subplot. We determined coniferous and deciduous canopy heights by measuring We used a completely randomized experimental design heights of 5 random overstory trees in each category with 5 treatments replicated >3 times/year over 4 years with a clinometer. We estimated percent canopy cover for breeding birds and 2 years for small mammals. in all years using a spherical densiometer (Lemmon Treatments were control (n =14); WSI-no burn (WSI; n 1957). = 14); WSI, first growing season postburn (WSIB1; n = 17); WSI, second growing season postburn (WSIB2; n = We characterized the vertical vegetation profile in 1992 14); and WSI, third growing season postburn (WSIB3; n and 1993 with a 10-m pole divided into 1-m segments = 14). In 1992, we randomly chose 12 stands from a list at 9 points within each subplot. Points lay 2.5 m apart of treated stands (n = 61), in addition to 3 randomly along perpendicular lines that intersected subplot center. chosen