Timothy S. McCay

Effects of a community restoration fire on small mammals and herpetofauna in the southern Appalachians

As part of the Wine Spring Creek ecosystem management project on the Nantahala National forest, North Carolina, we assessed effects of a community restoration fire on small mammals and herpetofauna in the upper slope pitch pine (Pinus rigida) stands, neighboring midslope oak (Quercus spp.) stands and rhododendron (Rhododendron maximum) dominated riparian areas during 1995 and 1996. Using drift-fence arrays with pitfalls and snap-trapping, we collected these small mammals: masked shrew (Sorex cinereus), smoky shrew (S. fumeus), water shrew (S. palustris), pygmy shrew (S. hoyi), northern short-tailed shrew (Blarina brevicauda), deer mouse (Peromyscus maniculatus), white-footed mouse (P. leucopus), golden mouse (Ochrotomys nuttalli), southern red-backed vole (Clethrionomys gapperi), pine vole (Microtus pinetorum) and woodland jumping mouse (Napaeozapus insignis). Herpetofauna collected from drift-fence arrays and time-constrained searches included: eastern newt (Notophtalmus viridescens), seepage salamander (Desmognathus aeneus), mountain dusky salamander (D. ochrophaeus), Blue Ridge two-lined salamander (Eurycea wilderae), spring salamander (Gyrinophilus porphyriticus), Jordan’s salamander (Plethodon jordani), wood frog (Rana sylvatica), five-lined skink (Eumeces fasciatus), eastern garter snake (Thamnophis sirtalis), and northern ringneck snake (Diadophis punctatus). Prior to the prescribed community restoration fire in the spring of 1995, there were no significant differences in small mammal or herpetofauna collections between burned and control areas. Post-treatment in 1995 and 1996, showed no significant differences among collections of most species between burned and control areas. Slope position accounted for more variation among the species of greatest abundance than did burning. Concern for the effects of prescribed fire as a management tool on small mammals and herpetofauna in the southern Appalachians seems unwarranted. # 1999 Elsevier Science B.V. All rights reserved.

Influence of Soil Buffering Capacity on Earthworm Growth, Survival, and Community Composition in the Western Adirondacks and Central New York

Abstract We examined how buffering capacity affected natural earthworm communities by comparing well-buffered soils in Madison County in central New York and poorly buffered soils in the western Adirondacks. We also investigated how liming and interspecific competition influenced growth and survival of 2 exotic taxa (Eisenia foetida and Amynthas agrestis) in Adirondack and central New York soils using laboratory microcosms. Earthworms were more abundant and diverse in central New York soils than in western Adirondack soils. Interspecific competition had no effect on growth or survival of either species in microcosms. Survival of A. agrestis was low in Adirondack soils without lime, but liming increased survival to that of central New York soils. Growth rates of E. foetida were lowest in Adirondack soils without lime, but highest in Adirondack soils with lime. Our results suggest that high soil acidity may be preventing exotic earthworms from successfully invading the western Adirondacks.

Processes regulating the invasion of European buckthorn (Rhamnus cathartica) in three habitats of the northeastern United States

Invasion by exotic plants often is restricted by processes, such as seed predation, acting on early life-history stages; however, the relative importance of these processes might vary among habitats. Modern human land use has created a mosaic of habitats in many landscapes, including the landscape of the northeastern United States. European buckthorn (Rhamnus cathartica) is an exotic plant that has achieved varying success in North American habitats. We studied dispersal, seed survival, germination, and seedling survival of buckthorn populations at four plots in each of sugar maple (Acer saccharum) forests, old fields, and abandoned conifer plantations in central New York State. Dispersal was low in maple forests, as evidenced by low collection rates of R. cathartica seeds in seed traps. Rates of post-dispersal seed predation were highest in maple forests and lowest in old fields, suggesting greater use of maple forests by granivorous rodents. Germination rates did not vary among seeds planted in soils of these habitats when studied in the laboratory despite differences in soil pH. Survival of transplanted seedlings was low in maple forests relative to old fields and plantations. Buckthorn invasion of old fields and abandoned plantations was not strongly constrained by factors we considered, and the buckthorn populations in these habitats were large. A combination of low dispersal by frugivores, low seed survival due to predation, and low seedling survival due to dim light conditions apparently prevents R. cathartica from invasion of intact maple forests of our area. Native fauna and canopy closure may act synergistically to reduce success of invasive plants in natural habitats.

Influence of Age, Sex and Time of Year on Diet of the Bobcat (Lynx rufus) in Pennsylvania

Abstract Diet of the bobcat (Lynx rufus) in the mid-Atlantic region of the United States is poorly known. Age, sex and time of year are thought to influence bobcat prey selection, but accounts vary. We examined the contents of 85 bobcat stomachs taken from Pennsylvania during autumn and winter 2000–2002. White-tailed deer (Odocoileus virginianus) and rabbits (Sylvilagus sp.) occurred most frequently as prey. A larger percentage of female bobcats consumed lagomorphs (28%) than did males (12%; P = 0.04). More male bobcats consumed meso-mammals (14%), including raccoons and porcupines, than did females (2%; P = 0.04). Diet did not differ between bobcats <2 y and bobcats ≥2 y. Variety of prey eaten was larger in autumn than in winter. Sexual differences in diet may be related to sexual dimorphism in this species and may help to effect interspecific niche partitioning. Winter weather reduces the availability of certain prey items in this region and may decrease the bobcats ability to travel and hunt effectively.

Selection of Seeds of Common Native and Non-native Plants by Granivorous Rodents in the Northeastern United States

Abstract Post-dispersal seed predation by rodents represents a potentially important element of biotic resistance to plant invasion. Selection for five different types of seeds by granivorous rodents was studied in maple-beech forests, old fields and conifer plantations in Madison County, New York. Rodents visited dishes containing equal masses of seeds of the native Cornus amomum and Rubus idaeus, and the non-native Lonicera morrowii, Rhamnus cathartica and Rosa multiflora. Greater masses of C. amomum and R. idaeus seeds were consumed during a night of mammal visitation than of the three non-native species, and pattern of selection did not differ among habitats. Rodents encountered seed dishes sooner in forested habitats than old fields. The primary seed predators in our region, Peromyscus spp., were more common at forests and plantations than old fields. Patterns of habitat use by Peromyscus spp. may aid in resisting invasion of intact forests by invasive plants; however, selection of native over non-native seeds may facilitate differential establishment of non-native invaders.

Spatial analysis of species richness of shrews (Soricomorpha: Soricidae) in North America north of Mexico

We used geographic ranges of North American shrews and environmental data to better understand spatial distribution of species richness in the Soricidae. Richness was examined as a function of latitude and longitude and was compared with climatic variables at random points (≥90 km apart). Latitudinal trend in richness was parabolic with a maximum near 48°N, consistent with the general hypothesis that diversity is limited by energy to the north and by moisture to the south. Precipitation, snowfall, and July heating degree days were positively related to shrew richness. Richness of North American Soricidae was high in areas where topographic relief allowed for a variety of forested habitats and precipitation was high, such as the Southern Appalachians and Pacific Northwest. This broad, geographic study supports the idea that environmental moisture importantly limits distributions of shrews, which has been

SOIL LIMING MITIGATES THE NEGATIVE EFFECT OF SIMULATED ACID RAIN ON THE ISOPOD, PORCELLIO SCABER

Terrestrial isopods are sensitive to variability in the pH-buffering capacity of soils, partly because of their high requirement for calcium. Acid deposition resulting from air pollution can reduce the quality of the environment for isopods and other forest-floor animals through the reduction of available calcium and increased acidity. We examined the potential for calcium carbonate (lime) application in soil to mitigate negative effects of simulated acid deposition on the isopod, Porcellio scaber Latreille (1804), in laboratory microcosms. Growth rate of animals was lower when subjected to strongly acidic simulated precipitation compared to weakly acidic simulated precipitation. Animals in limed microcosms had higher growth rates and lower risk of mortality than those in conditions without lime. Whole-body calcium concentration was higher for isopods in limed than unlimed microcosms receiving strongly acidic simulated precipitation. These results underscore the importance of buffering substrates for isopods and suggest that application of lime may be a productive mitigative technique in areas affected by acid rain.

Demography and distribution of the invasive Rhamnus cathartica in habitats of a fragmented landscape1

Abstract Forest fragmentation and abandonment of lands managed for agriculture are widespread processes in eastern North America that might promote the expansion of exotic pests. We studied populations of Rhamnus cathartica L. (European buckthorn), an invasive alien plant in North America, in maple-beech forests, abandoned agricultural fields, and unmanaged conifer plantations in central New York State. Surveys and neighborhood functions were used to examine demography and spatial distribution. Populations of R. cathartica in maple-beech forests were sparse (112 ha−1), dominated by seedlings and saplings, and strongly aggregated in space. Populations of R. cathartica in plantations, by contrast, were dense (7,717 ha−1), not strongly concentrated at the low end of the diameter distribution, and less strongly aggregated than those in other habitats. Old fields included a high density of R. cathartica plants (5,912 ha−1), which were predominantly seedlings and strongly aggregated. Seedling density was positively related to availability of light at our forested plots, and plants were clustered near walking trails at three of four maple-beech plots. At all old field and two of four plantations, seedlings were spatially associated with fruiting R. cathartica, suggesting that they served as recruitment foci. Further, seedlings also were associated with non-fruiting adult R. cathartica at 2 of 3 old-field and 2 of 4 plantation plots. Unmanaged conifer plantations with numerous canopy openings may permit colonization and population growth of R. cathartica. Management for closed-canopy forest and the elimination of plants, particularly fruiting conspecifics, serving as recruitment foci are potentially successful approaches toward control of R. cathartica.

Timing of Parturition of Three Long-tailed Shrews (Sorex spp.) in the Southern Appalachians

Abstract Timing of parturition has been proposed as a factor allowing coexistence of sympatric shrews. We examined the timing of parturition for three species of sympatric long-tailed shrews (Sorex) in the southern Appalachians. We found a marked similarity in patterns of parturition among these species, with significant correlations between S. fumeus and both S. cinereus (r = 0.86, P = 0.0004) and S. hoyi (r = 0.72, P = 0.0080). However, parturition dates for S. cinereus and S. hoyi were not significantly correlated (r = 0.43, P = 0.1588), with the average parturition date significantly earlier for S. hoyi. We suggest that patterns of breeding among Sorex spp. in the southern Appalachians are highly similar, although early breeding may help S. hoyi avoid competition with S. cinereus.

Distribution and Habitat of the Endemic Earthworm Eisenoides lonnbergi (Michaelsen) in the Northeastern United States

Abstract Eisenoides lonnbergi is one of just a few native earthworm species known from north of the most recent glacial maximum and has been found most commonly in saturated soils. We sampled earthworms from wetlands in Upstate New York and compiled published and unpublished records of E. lonnbergi to better describe the distribution and habitat associations of this species in the Northeast. We found E. lonnbergi at 14 of 22 sampled sites, including 8 of 14 riparian areas and 6 of 8 wetlands of other types (bogs, fens, and swamps). Soil pH at colonized sites varied from 3.4 to 8.5. At the 3 most acidic sites, E. lonnbergi was the only species detected by our sampling. Published records with habitat data also support an association between E. lonnbergi and wetland habitats of variable pH, both above and below the most recent glacial maximum. Eisenoides lonnbergi is strongly associated with wetlands, including some habitats, such as acidic bogs, in which it may be the only earthworm present. Land managers and conservation biologists should consider Eisenoides lonnbergi along with other native species sensitive to the loss of wetlands in the Northeast.