Bottomland Hardwood Research Articles

Habitat associations of saproxylic beetles in the southeastern United States: A comparison of forest types, tree species and wood postures

Saproxylic beetles are highly sensitive to forest management practices that reduce the abundance and variety of dead wood. However, this diverse fauna continues to receive little attention in the southeastern United States even though this region supports some of the most diverse, productive and intensively managed forests in North America. In this replicated three-way factorial experiment, we investigated the habitat associations of saproxylic beetles on the coastal plain of South Carolina. The factors of interest were forest type (upland pine-dominated vs. bottomland hardwood), tree species ( Quercus nigra L., Pinus taeda L. and Liquidambar styraciflua L.) and wood posture (standing and downed dead wood, i.e., snags and logs). Wood samples were taken at four positions along each log and snag (lower bole, middle bole, upper bole and crown) ∼11 months after the trees were killed and placed in rearing bags to collect emerging beetles. Overall, 33,457 specimens from 52 families and ≥250 species emerged. Based on an analysis of covariance, with surface area and bark coverage as covariates, saproxylic beetle species richness differed significantly between forest types as well as between wood postures. There were no significant interactions. Species richness was significantly higher in the upland pine-dominated stand than the bottomland hardwood forest, possibly due to higher light exposure and temperature in upland forests. Although L. styraciflua yielded more beetle species (152) than either Q. nigra (122) or P. taeda (125), there were no significant differences in species richness among tree species. There were also no relationships evident between relative tree abundance and observed or expected beetle species richness. Significantly more beetle species emerged from logs than from snags. However snags had a distinct fauna including several potential canopy specialists. Our results suggest that conservation practices that retain or create entire snags as opposed to high stumps or logs alone will most greatly benefit saproxylic beetles in southeastern forests.

Establishing a Research and Demonstration Area Initiated by Managers: The Sharkey Restoration Research and Demonstration Site

Abstract As forest scientists increase their role in the process of science delivery, many research organizations are searching for novel methods to effectively build collaboration with managers to produce valued results. This article documents our experience with establishment of a forest restoration research and demonstration area in the Lower Mississippi Alluvial Valley (LMAV), a region that has experienced extensive afforestation of former agricultural land over the past 15 years. Although basic establishment techniques for production plantations had been developed and applied on small areas, land managers lacked critical knowledge to implement operational-scale afforestation practices that would accommodate multiple forest restoration objectives. In 1993, managers with the US Fish and Wildlife Service made a 1,700-ac agricultural tract available to scientists interested in partnering research and demonstrating various aspects of bottomland hardwood ecosystem restoration. Through collaborative efforts, resource managers and scientists have installed numerous experiments on the Sharkey Restoration Research and Demonstration Site to address relevant issues in afforestation and restoration of bottomland hardwood ecosystems. Development of this research and demonstration area has provided a science-based resource for educating landowners, foresters, wildlife managers, and the general public on afforestation techniques appropriate for restoration of bottomland hardwood forests; has served as a platform for scientists and land managers to cooperate on the development of innovative approaches to forest restoration; and has provided a venue for education and debate among policymakers active in the LMAV. Early results showed the viability of low-cost techniques such as direct seeding oaks, as well as introducing the interplanting technique for rapid development of forest conditions. We recognize that the value of the research and demonstration site is attributed in part to site characteristics and experimental design, and expect continued work at the location to contribute to improved afforestation practices that will foster establishment of sustainable bottomland hardwood forests.

Influence of incidence angle on detecting flooded forests using C-HH synthetic aperture radar data

Hydrology is the single most important abiotic factor in the formation and functioning of a wetland. Many limitations still exist to accurately characterizing wetland hydrology over large spatial extents, especially in forested wetlands. Imaging radar has emerged as a viable tool for wetland flood mapping, although the limitations of radar data remain uncertain. The influence of incidence angle on the ability to detect flooding in different forest types was examined using C-HH Radarsat-1 data (23.5°, 27.5°, 33.5°, 39.0°, 43.5°, and 47.0°) during the leaf-off and leaf-on seasons. The ability to detect flooding under leaf-on conditions varied much more according to incidence angle while forest type (open canopy tupelo-cypress, tupelo-cypress, and bottomland hardwood) had a greater effect during the leaf-off season. When all forest types were considered together, backscatter generally decreased with increasing incidence angle under all conditions (2.45 dB between 23.5° and 47.0° flooded, leaf-off; 2.28 dB between 23.5° and 47.0° not flooded, leaf-off; 0.62 between 23.5° and 43.5° flooded, leaf-on; 1.73 dB between 23.5° and 43.5° not flooded, leaf-on; slope was not constant between incidence angles), but the distinction between flooded and non-flooded areas did not decline sharply with incidence angle. Differentiation of flooded and non-flooded forests was similar during the leaf-off and leaf-on seasons. The ability to detect inundation under forest canopies was less than expected at smaller incidence angles and greater than expected at larger incidence angles, based on the results of previous studies. Use of a wider range of incidence angles during the entire year increases the temporal resolution of imagery which may, in turn, enhance mapping of inundation beneath forest canopies.

A Stand-Development Approach to Oak Afforestation in the Lower Mississippi Alluvial Valley

Abstract Oak (Quercus spp.) afforestation in the Lower Mississippi Alluvial Valley has involved planting 1-year-old bareroot seedlings on a relatively wide spacing in single-species stands or planting light-seeded species with oaks to form mixed-species stands. In the former case, the developing single-species stands have limited future management options because they do not provide structures that favor quality wildlife habitat or quality sawtimber production. In the latter case, species mixtures are being planted with little knowledge of subsequent stand development, leading to an inability to predict future stand composition for management purposes. In this article, we present a system to determine bottomland tree planting mixtures that will create single-cohort, mixed-species stands with a component of high-quality bottomland oak. Using individual species ecological life-history characteristics, such as early height growth pattern, relative twig diameter and durability, and developmental patterns in natural stands, bottomland species are rated for their ability to provide beneficial training effects that will lead to the development of quality oak boles. Incorporating such a system to determine species value in mixtures should provide an increased number of future options to meet explicit management objectives and promote improved restoration of bottomland hardwood ecosystems.

Predominant Use of Windthrows by Nesting Eastern Woodrats (Neotoma Floridana) in the South Carolina Coastal Plain

ABSTRACT We conducted a study of nest site selection by the eastern woodrat (Neotoma floridana) in the South Carolina coastal plain. We identified 40 active nests in three macrohabitats: a bottomland hardwood–upland pine ecotone, a southern mixed hardwood forest and a disturbed maritime forest. We further conducted an analysis of 21 microhabitat variables at 27 active nests, identified through live-trapping and release. Previous studies suggest that stick houses are preferred nest sites throughout N. floridana's range, and that dwarf palmetto (Sabal minor) may be an important indicator of woodrat habitat in North Carolina. Eastern woodrats inhabited windthrown rootmasses in 77.5% of nests at our study sites. S. minor and stick houses were completely absent from two of the three habitats. Multivariate analysis revealed that nest sites differed from paired non-nest sites by containing higher coarse woody debris and rootmass volume, and lower basal area. We recommend that N. floridana population surveys rout...

A Road Survey of Amphibians and Reptiles in a Bottomland Hardwood Forest

The impact of roads on amphibian and reptile numbers at Texas Parks and Wildlife Department's Old Sabine Bottom Wildlife Management Area (OSBWMA), a bottomland hardwood forest was studied from 1 June 2003 to 1 June 2004 by vehic- ular and pedestrian surveys. One weekly survey was conducted in the morning and the other in late afternoon. Vehicular surveys were conducted by driving 16.1 km/hr over the roads (9.5 km) through the bottomland twice per week. Pedestrian surveys were conducted on 6 sections of those roads (1.3, 1.3, 1.3, 1.1, 0.3, and 0.3 km), three on the larger main gravel road, and three sections on smaller dirt tributaries, twice weekly. One section of the main road (1.3 km) was located near three operat- ing oil rigs. The other 5 sections of the survey route traversed forested regions of the management area. The 3 sections located along the main gravel road were subject to regular vehicular traffi c by the public and OSBWMA staff. The three sections located along the dirt trail tributaries had primarily foot travel with much less and slower ve- hicular traffi c. GPS coordinate, date, and condition (alive or dead) of the specimens were recorded. In the summer, 10.5% of the amphibians and reptiles were found dead on the road (DOR). The number of DORs in the fall was 47.1%, and 64.3% in the spring. For amphibians, 28.1% were DOR (summer), 20% in the fall, and 83.3% in the spring. In the winter months, no specimens were observed on the roads. Road traffi c in this bottomland impacts reptiles extensively in the fall and amphibians in the summer, whereas both reptiles and amphibians are affected by road traffi c in the spring. Smaller roads and the section of road with oil rigs had lower mortality rates, while areas with adjacent borrow pits had higher mortality rates.

Five-year radial growth of red oaks in mixed bottomland hardwood stands

We studied the relationships among 5-year radial (diameter and basal area) growth of red oak (genus Quercus, subgenus Erythrobalanus) crop trees and predictor variables representing individual tree vigor, distance-dependant competition measures, and distance-independent competition measures. The red oaks we examined are representative of the commercially and ecologically important oak species of the bottomland hardwood forests of the southeastern US. The crown class score, a quantitative measure of crown class and tree vigor, performed best in accounting for the variability in tree diameter growth. Plot-level variables failed to account for a significant proportion of the variability in tree radial growth. The basal area of the first-order neighbors that were taller than the crop trees and located within 2.4 times the mean overstory crown radius had the highest negative correlation with crop tree 5-year radial growth. Red oaks were a major part of these competitors and likely exerted the greatest competitive pressure. However, crop tree radial growth was positively associated with the basal area of the red oaks which were indirect (second order) neighbors and which were taller than the crop trees. It is possible that indirect neighbors do not compete with the crop trees, but they likely compete with the direct competitors of the crop trees, thus having an indirect positive influence on crop tree growth. Such reasoning is consistent with previously observed spatial dependence up to four times the mean overstory crown radius. The findings may have implications for thinning hardwoods stands and crop tree management in that foresters need to take into account (1) oak intra-genus competition, (2) the negative competitive effect of direct neighbors, and (3) the potentially positive effect of the indirect neighbors, the competitors’ competitors.

The importance of hydrology in restoration of bottomland hardwood wetland functions

Bottomland hardwood (BLH) forests have important biogeochemical functions and it is well known that certain structural components, including pulsed hydrology, hydric soils, and hydrophytic vegetation, enhance these functions. It is unclear, however, how functions of restored BLH wetlands compare to mature, undisturbed wetlands. We measured a suite of structural and functional attributes in replicated natural BLH wetlands (NAT), restored BLH wetlands with hydrology re-established (RWH), and restored BLH wetlands without hydrology re-established (RWOH) in this study. Trees were replanted in all restored wetlands at least four years prior to the study and those wetlands with hydrology re-established had flashboard risers placed in drainage ditches to allow seasonal surface flooding. Vegetation, soils, and selected biogeochemical functions were characterized at each site. There was a marked difference in woody vegetation among the wetlands that was due primarily to site age. There was also a difference in herbaceous vegetation among the restored sites that may have been related to differences in age or hydrology. Water table fluctuations of the RWH wetlands were comparable to those of the NAT wetlands. Thus, placing flashboard risers in existing drainage ditches, along with proper management, can produce a hydroperiod that is similar to that of a relatively undisturbed BLH. Average length of saturation within the upper 15 cm of soils was 37, 104, and 97 days for RWOH, RWH, and NAT, respectively. Soil moisture, denitrification potential, and soluble organic carbon concentrations differed among wetland sites, but soil carbon and nitrogen concentrations, heterotrophic microbial activity, and readily mineralizable carbon concentrations did not. Significant linear relationships were also found between soil moisture and heterotrophic microbial activity, readily mineralizable carbon, and soluble organic carbon. In addition, sedimentation rates were higher in NAT and RWH wetlands than in RWOH sites. Results of this study suggest that reconnection of bottomland hardwood wetlands to their surrounding watershed through the restoration of surface hydrology is necessary to restore wetland functions important to nutrient and sediment removal.

Oak regeneration in southeastern bottomland hardwood forest

Oaks ( Quercus spp.), such as cherrybark oak ( Quercus pagoda Raf.), are valuable timber species in bottomland hardwood (BLH) forests of the southeastern U.S. Oak regeneration is affected by plant flooding tolerance; wind disturbances or forest harvests; and interactions with seed predators and herbivores. We investigated oak regeneration (seedling establishment and early growth, composition of seedling and sapling banks) in experimental openings, from 7 to 40 m radius, created by group-selection harvest in a BLH forest. Seed dispersal, seed predation, and microsite conditions on the forest floor, rather than canopy openness, were the first filters on oak regeneration. In the first 3 years after gap creation, naturally established oak seedlings were most abundant in relatively ‘undisturbed’ microsites with litter cover and around gap edges. Swamp chestnut oak ( Quercus michauxii Nutt.) germination was inhibited in pits, and seedling establishment was greatest under edge or less open canopy. Cherrybark oak seedling establishment and growth were reduced by seed predation and shade. Six years after acorns were planted, swamp chestnut oak seedling height and maximum root depth were greatest in gap centers. Ten years after gap creation, oaks were more abundant beneath the surrounding forest canopy, but were tallest in gap centers. Thus, in contrast to its lack of influence on acorn germination and initial establishment, canopy openness appears to filter oak persistence and height growth in the seedling bank. Forest management that provides level or raised microsites beneath thin canopy and protection from seed predation can facilitate oak seedling establishment in southeastern BLH forests. Maintaining a thin to open canopy can promote oak persistence in the seedling bank; growth into the sapling bank may require reopening the canopy if gap centers have grown up over time. Although longer study time is needed to capture regeneration from seed germination through ascent from the sapling layer into the subcanopy and canopy strata, this large field experiment has revealed there is no optimal gap size for oak regeneration. Rather, biotic interactions, canopy openness, and particularly flood duration at the microsite scale create complex patterns of oak abundance and heights in the seedling and sapling layers following disturbance in bottomland hardwood forests.

Dendroclimatic Analysis of a Bottomland Hardwood Forest: Floodplain vs. Terrace Responses1

Successful dendroclimatic reconstructions require separating trees with strong climate records in their tree rings (sensitive trees) from those with weak climate signals (complacent trees). Traditionally, dendroclimatologists identify sensitive trees based on their growing site and favor trees from high elevation or xeric sites; however, recently dendroclimatologists have explored the potential of bottomland hardwood sites because they harbor some of the oldest trees in the eastern United States. The objective of this study was to contrast the dendroclimatic sensitivity of Fagus grandifolia Ehrh. growing on a floodplain vs. a river terrace. Although the difference in elevation between these two sites was only 10 m, this represented a substantial difference in frequency and duration of flooding. Tree cores from Fagus grandifolia growing on the floodplain and on the terrace were collected to create two master chronologies from the tree ring widths. The ring width indices from these two sites were correlated with temperature, precipitation, and Palmer Drought Severity Index. At the terrace site, significant dendroclimatic correlations existed during the summer months with Palmer Drought Severity Index, precipitation, and temperature. No significant dendroclimatic relationships existed for the Fagus grandifolia growing on the floodplain. These results identify the fine line that exists between sensitive and complacent trees within bottomland hardwood sites and identifies a geomorphic region (terrace sites) that has traditionally been overlooked in dendroclimatic studies but which produces sensitive tree ring records.

The Species-Abundance Distribution of Snakes in a Bottomland Hardwood Forest of the Southern United States

Species-abundance distributions often form a log series curve with a few common species and a large proportion of rare species. Niche apportionment and random processes such as dispersal and local extinction are reflected in the structuring of abundance ranks among species within a community. Bottomland hardwood forests of the southern United States have high biotic production because of flood pulses that bring in nutrients. The assemblage of snakes in these environments is diverse both in terms of diet and morphology. In this habitat, the high levels of some resources should be involved in the abundance ranks of the most common species, but other factors (e.g., body size) may be important in the abundance ranks of the less common species. We examined the abundances of snakes in a 2300-ha bottomland deciduous forest in northeastern Texas. Fourteen total species were recorded, but only in one year were all species collected. Three semiaquatic species, Thamnophis proximus, Nerodia erythrogaster, and Agkistrodon piscivorus were the most common. These three species eat fish and amphibians that are concentrated in ephemeral pools, but their foraging methods differ. Several other species had intermediate abundances and a wide variety of diets. Smaller and heavier species did not have lower abundances, and we suggest that, although poor dispersal ability may be involved in the rarity of some species, there are likely several factors involved. We hypothesize that both niche characteristics and random processes are involved in producing the stair-step appearance of the abundance ranks of these snakes.

Hedonic Analysis of Hunting Lease Revenue and Landowner Willingness to Provide Fee-Access Hunting

Abstract Selling hunting access may supplement household income, yet only a small proportion of nonindustrial private (NIP) landowners in United States lease the right to hunt their land. Based on a survey of Mississippi landowners, the decision to lease hunting rights and factors influencing lease revenue per leased hectare were analyzed. The two issues were jointly modeled consistent with Heckman's sample selection model, and the lease revenue was specified in accordance with hedonic pricing theory. Empirical results showed that landowner concerns about loss of privacy, accident liability, and conflicts with personal use of land reduced the likelihood of leasing; total landownership and specific landowner characteristics increased it. With regards to factors explaining differences in lease revenue per leased hectare, bottomland hardwoods commanded a greater premium than many other land uses. In addition, lease revenue per hectare was distinctly higher where a landowner had expertise in managing a hunting lease enterprise. These findings have implications for landowners interested in managing wildlife-associated enterprises and public agencies engaged in the provision of natural resource-based recreation.

Associations Between Two Bottomland Hardwood Forest Shrew Species and Hurricane-Generated Woody Debris

Abstract We investigated associations between soricids and coarse woody debris (CWD) in bottomland hardwood forests impacted by Hurricane Hugo. The objectives were to evaluate CWD loadings at three forests disturbed by Hurricane Hugo, monitor soricid captures at these forests, and identify habitat associates of soricids Pitfall traps were used to sample soricids from January 2002–December 2003, and habitat parameters (CWD, vegetation, soils, and microsite) surrounding pitfalls were sampled. We found CWD volume was significantly higher at study sites that experi enced highest hurricane wind speeds. Captures of soricids were highest in forests with high CWD loadings, and regression models associated soricids with log cover and CWD volume. Sorex longirostris (southeastern shrew) was associated with logs in an advanced state of decay and woody litter. Blarina carolinensis (southern short tailed shrew)was associated with log cover and leaf-litter cover. Soricid captures also increased with close proximity of C...

Winter Relative Abundance and Habitat Associations of Swamp Rabbits in Eastern Arkansas

Habitat loss coupled with decline in harvest has raised concern for Sylvilagus aquaticus (swamp rabbit) in Arkansas. We assessed relative abundance and habitat associations of swamp rabbits in eastern Arkansas using presence of latrine sites. We searched for fecal pellets at randomly chosen sites during winters 2002–03 and 2003–04. Swamp rabbits were detected at 85% and 76% of sites searched during years 1 and 2, respectively. Bignonia capreolata (crossvine) stem density was significantly greater at sites inhabited by swamp rabbits (mean = 625, SE = 141) than at uninhabited sites (mean = 0.00, SE = 0.00) in year 1, but no differences were found in year 2. We found no relationship between woodland tract size and pellet-group density. Logistic regression predicted presence of swamp rabbits 88.3% of the time based on crossvine density and percent ground cover of grasses. To understand the potential for conserving swamp rabbit populations in Arkansas, it will be necessary to assess remaining bottomland hardwood stands in relation to the quality of swamp rabbit habitat.

Micropropagation of the Endangered Shrub Pondberry (Lindera melissifolia [Walt.] Blume)

A micropropagation protocol using shoot cultures is described for Lindera melissifolia, a federally listed endangered shrub endemic to the southeastern United States. Stock plants were harvested from native L. melissifolia populations growing in the lower Mississippi Alluvial Valley. In vitro proliferation was on woody plant medium supplemented with 1 μm zeatin. After 6 weeks, zeatin level was increased to 5 μm. Treatment of micropropagated shoots with a liquid auxin (2 indole-3-butyric acid : 1 1-naphthalenacetic acid) resulted in a low mean rooting percentage (≤44%) compared with rooting in the absence of auxins and on a pure peat medium ex vitro, which increased rooting to ≥80%. Time to rooting was 8 weeks. Plants were acclimatized for 2 weeks, then potted in a 2 peat : 1 perlite medium supplemented with superphosphate, 10N–10P–10K, and Milorganite. Micropropagated L. melissifolia stecklings have been successfully outplanted in both controlled and field studies at the Center for Bottomland Hardwoods Research (Stoneville, Miss.).

Reduced Nest Predation of Cavity-Nesting Wood Ducks During Flooding in a Bottomland Hardwood Forest

Abstract Abstract The importance of flooding to birds that nest in bottomland hardwood forests is poorly understood, in part because floods are difficult to predict. A large flood occurred in 2002, during our study of cavity-nesting Wood Ducks (Aix sponsa) in the Mississippi River floodplain. Nests were depredated prior to and after, but not during, the four-week flood. This observation prompted a retrospective analysis of flooding, nest predation, and nest success for our three-year study period of 2000–2002 and with a dataset extending back to 1995. Nest predation was lower and nest success was higher in the floodplain during floods. Flood conditions did not significantly affect nest success or nest predation rates in the adjacent upland, but nest success in upland forest was higher than in the floodplain during dry periods. Historically, spring flooding of riparian areas may to some extent have mitigated nest predation in bottomland forests.

Prioritizing Bottomland Hardwood Forest Sites for Protection and Augmentation

Abstract Bottomland hardwood forest has been greatly diminished by conversion to agriculture. Less than 25% of the pre-Columbian bottomland hardwood forests remain in the southeastern United States. Because of the valuable ecological and hydrological functions performed by these forests, their conservation and restoration has been a high priority. Part of these restoration efforts has focused on developing tools that can be used for both assessments at the landscape level and policy implementation at the local level. The distribution of bottomland hardwood forests in the Cache and White River watersheds in eastern Arkansas were examined using existing GIS databases. Criteria were developed to select areas that should be conserved or augmented for wildlife habitat. Over 67% of the study area was classified as agriculture, with bottomland hardwood forest the next largest habitat class. The thickness of a forest fragment was defined as the radius of the largest circle that can be inscribed in a fragment. Thi...

Effects of Selective Logging on Breeding Bird Communities in Bottomland Hardwood Forests in Louisiana

Bottomland hardwood forests of the southeastern United States support a rich avifauna, including >20 species of conservation concern; understanding the impact of land use practices on these communities is critical to their conservation. Selective timber harvesting is a common management practice in southern bottomland hardwood forests, but little research has examined impacts >5 years after harvesting. We studied breeding bird communities in selectively harvested bottomland forests in northeastern Louisiana during 2003–2004. We conducted point counts in recently harvested stands (1–5 yr postharvest) and older harvests (12–18 yr postharvest); we paired each with a reference stand that had not been harvested for >30 years. Of 35 species with sufficient detections for analysis, we found evidence that abundances of 17 species differed among treatments. Three species were sensitive to creation of canopy openings by timber harvests, including 2 species of concern in the Mississippi Alluvial Valley, USA, prothonotary warbler (Protonotaria citrea) and Acadian flycatcher (Empidonax virescens). However, 4 species of concern often associated with densely vegetated canopy gaps were more abundant in older harvests than in reference stands: Swainson's warbler (Limnothlypis swainsonii), hooded warbler (Wilsonia citrina), white-eyed vireo (Vireo griseus), and Kentucky warbler (Oporornis formosus). As expected, a suite of species typically associated with shrub and forest-edge habitats was more abundant in recent harvests than in reference stands. We conclude that selective logging has a strong influence on bird abundances in both recent and older harvests in bottomland forests. With the exception of Acadian flycatcher, older harvests and reference stands supported similar abundances of the species typically found in closed-canopy bottomland forests. In addition, older harvests supported substantially higher abundances of gap-dependent species than other treatments. Our results should be useful to land managers and conservation planners evaluating short- and long-term effects of timber management practices on breeding birds in the Mississippi Alluvial Valley. However, measures of breeding productivity are necessary to evaluate more fully the habitat quality of harvested forests.

Presence and Absence of Bats Across Habitat Scales in the Upper Coastal Plain of South Carolina

During 2001, we used active acoustical sampling (Anabat II) to survey foraging habitat relationships of bats on the Savannah River Site (SRS) in the upper Coastal Plain of South Carolina. Using an a priori information-theoretic approach, we conducted logistic regression analysis to examine presence of individual bat species relative to a suite of microhabitat, stand, and landscape-level features such as forest structural metrics, forest type, proximity to riparian zones and Carolina bay wetlands, insect abundance, and weather. There was considerable empirical support to suggest that the majority of the activity of bats across most of the 6 species occurred at smaller, stand-level habitat scales that combine measures of habitat clutter (e.g., declining forest canopy cover and basal area), proximity to riparian zones, and insect abundance. Accordingly, we hypothesized that most foraging habitat relationships were more local than landscape across this relatively large area for generalist species of bats. The southeastern myotis (Myotis austroriparius) was the partial exception, as its presence was linked to proximity of Carolina bays (best-approximating model) and bottomland hardwood communities (other models with empirical support). Efforts at SRS to promote open longleaf pine (Pinus palustris) and loblolly pine (P. taeda) savanna conditions and to actively restore degraded Carolina bay wetlands will be beneficial to bats. Accordingly, our results should provide managers better insight for crafting guidelines for bat habitat conservation that could be linked to widely accepted land management and environmental restoration practices for the region.

Cherrybark oak stump sprout survival and development five years following plantation thinning in the lower Mississippi alluvial valley, USA

Cherrybark oak (Quercus pagoda Raf.) stump sprouts were studied for 5 years in a 30-year-old plantation thinned to 70–75% stocking (light thinning) and 45–50% stocking (heavy thinning). Sprouting success, survival, number of sprouts per stump, and sprout height differed little between thinning treatments throughout the 5-year study period. Pre-harvest tree d.b.h. also had no influence on sprout survival and development. A 2-year drought reduced survival and may have influenced sprout development. Sprout clump survival dropped from 90% 1 year following thinning to 46% 3 years after thinning. Although sprout height averaged 337 cm 5 years after thinning, annual sprout growth decreased from 166 cm the first year after thinning to 33 cm in each of the last 2 growing seasons. Results indicated that bottomland hardwood regeneration evaluation models may underestimate the potential of oak stump sprouts to contribute to pre-harvest regeneration assessments. Further study in the role of stump sprouts to regenerate bottomland oak species is needed.