Treesearch

Ongoing surveys suggest that Pituophis ruthveni (Louisiana Pine Snake) has declined range-wide and that known extant populations have continued to decline. Seven known populations remain and occupy small, isolated blocks of habitat. Population sizes are unknown, but all of them are believed to be critically small. Management for the species’ recovery requires an understanding of its habitat requirements and how resources used by these snakes are distributed in space. Research suggests that the species’ primary prey, Geomys breviceps (Baird’s Pocket Gopher), prefers sandy, well-drained...

This study investigates the geomorphic effects of ford-type stream crossings in an off-highway vehicle (OHV) trail complex in the Ouachita National Forest, Arkansas. At a total of 15 crossing sites, we used a disturbed vs. undisturbed study design to assess soil truncation and an upstream vs. downstream design to assess in-channel effects. The 15 sites ranged from OHV crossings active for over 20 years to those on trails that have been closed to regular use for >5 years. All of the sites designated for OHV use (14 sites) exhibit soil loss of ~30 to 45 cm within the trail segments on either...

Beginning in 2009, we surveyed the vegetation of ephemeral ponds in Sabine and Nacogdoches counties in east-central Texas. These ponds are shallow and flat-bottomed, with a small but distinct flora dominated by grasses (Poaceae) and sedges (Cyperaceae). The floras of these ponds are most similar to those of flatwoods ponds located on the lower coastal plain. Once more common on the landscape, ponds of this type have been altered or destroyed by land-use changes and fire supporession, leading to massive encroachment of woody vegetation. The pond we sampled in Nacogdoches County has been...

Numerous isolated prairies exist, or existed, on the West Gulf Coastal Plain east of the main distribution of the prairie ecosystem. Changing land-use patterns and suppression of wildfire have destroyed almost all of these small prairie occurrences. Intensified restoration and management of degraded prairie habitat on the Sam Houston National Forest in southeastern Texas have been ongoing since approximately 2004. As a result, encroaching woody vegetation has been substantially reduced, and a vegetation structure consistent with prairie habitat has been restored. Beginning in 2008, we...

Restoration of the unique and diverse habitats of the Kisatchie Sandstone Hills requires the re-introduction of fire to reduce fuel accumulation and promote herbaceous vegetation, but some soils in the area are extremely erodible, and past fires have resulted in high erosion rates. Overstory and understory vegetation, downed woody fuels, and other stand attributes were measured on sites that received either no management or two prescribed burns after >20 years of fire exclusion. The two burns (one dormant season and one growing season) reduced the live fuel-load (understory biomass) and...

We examined slash from thinning treatments in a 21-year chronosequence of young-growth stands in southeast Alaska to determine the strength and persistence of slash effects on two key features of deer habitat quality: forage availability and deer mobility within thinned areas. We describe the main deterioration processes and their dynamics over time. We measured wood density of slash of various ages and present a model to estimate changes in wood density over time. This report also discusses factors that contribute to initial slash loading, slash deterioration, and effects on deer habitat.

This user's guide for the SILVAH computer program, version 6.2, supersedes the 1992 user's guide (Gen. Tech. Rep. NE-162). Designed for stand-alone Windows-based personal computers, SILVAH recommends a silvicultural prescription for a forest stand based on a summary and analysis of field inventory data. The program also includes a simulator that can be used to project stand growth and development, estimating yields from either prescribed or user-defined treatments. The software is distributed with an online help system and this printed user's manual. The computer program described in this...

This revision of the 1987 silvicultural guide includes updated and expanded silvicultural information on northern hardwoods as well as additional information on wildlife habitat and the management of mixed-wood and northern hardwood-oak stands. The prescription methodology is simpler and more field-oriented. This guide also includes an appendix of familiar tables and charts useful to practicing field foresters. Northern hardwood forest types can be managed as even- or unevenaged stands using a variety of silvicultural practices. In planning these practices, there are many factors to...

We surveyed diversity patterns and engaged in bioprospecting for bioactive compounds of fungi associated with the endemic macroalgae, Monostroma hariotii and Pyropia endiviifolia, in Antarctica. A total of 239 fungal isolates were obtained, which were identified to represent 48 taxa and 18 genera using molecular methods. The fungal communities consisted of endemic, indigenous and cold-adapted cosmopolitan taxa, which displayed high diversity and richness, but low dominance indices. The extracts of endemic and cold-adapted fungi displayed biological activities and may represent sources of...

Collection of non-urban ambient ozone data at regional or larger scales (for example, Peake and Fong 1990; Bytnerowicz et al. 2004) is cost- and labor-intensive. Collection efforts are often further complicated by difficulty of access to data collection sites, the need for climate-controlled facilities to house instrumentation, and a requirement for a connection to utility-grade (grid) power. Regional ozone is more often studied via modeling (for example, Kumar et al. 1994). Although nitrite-based passive samplers (Koutrakis et al. 1993; Vardoulakis et al. 2009) may be used to estimate...