Treesearch

Conservation needs for amphibians in managed timberlands may differ based upon the species present and the timber harvesting methods employed. Clearcuts have been documented to be detrimental to amphibians but the impacts of associated silvicultural edges and alternative harvesting treatments are not well understood. The primary objective of this study was to determine if amphibian abundances and body condition differed in thinned forests and intact forests, and in clearcuts and associated silvicultural edges. We also examined which environmental attributes were important in explaining...

We compared species richness and relative abundance of stream-associated amphibians in late-seral redwood forests with those in mid-seral, second-growth forests to examine the continued (as opposed to immediate) effects of timber harvest on amphibian populations. Lacking pre-harvest data on amphibian abundances for streams in the second-growth stands, we assumed that nearby tributaries transecting late-seral stands with similar topography and flora harbored similar numbers of animals as second-growth stands prior to harvest. The study was conducted in two blocks (ca. 160 km apart) with...

Secondary growth results in the radial expansion of woody stems, and requires the coordination of tissue patterning, cell differentiation, and the maintenance of meristematic stem cells within the vascular cambium. Advances are being made towards describing molecular mechanisms that regulate these developmental processes, thanks in part to the application of new genetic technologies to forest trees, and the extension of knowledge about evolutionarily conserved mechanisms from model annuals. New studies demonstrate a central role for developmental mechanisms that involve transcriptional...

We investigated habitat use and movements of the wandering salamander, Aneides vagrans, in an old-growth forest canopy. We conducted a mark-recapture study of salamanders in the crowns of five large redwoods (Sequoia sempervirens) in Prairie Creek Redwoods State Park, California. This represented a first attempt to document the residency and behavior of A. vagrans in a canopy environment. We placed litter bags on 65 fern (Polypodium scouleri) mats, covering 10% of their total surface area in each tree. Also, we set cover boards on one fern mat in each of two trees. We checked cover objects...

The goal of this study was to examine how introduced trout influence the distributions and abundances of a sub-alpine amphibian assemblage whose members display a variety of different life-history and defence strategies. Our study was conducted in the sub-alpine lentic habitats of three wilderness areas that form the core of the Klamath-Siskiyou Bioregion of northern California, a biodiversity 'hotspot' that supports the highest diversity of sub-alpine, lentic-breeding amphibians in the western USA. These wilderness areas contain no native fishes, but all have been populated with non-native...

In California's mixed-conifer forest, which historically had a regime of frequent fires, two conifers, Sequoiadendron giganteum and Pseudotsuga menziesii, were previously known to produce epicormic sprouts from branches. We found epicormic branching in a third mixed-conifer species, Abies concolor, 3 and 4 years after a wildfire in the central Sierra Nevada Mountains of California. Sprouting occurred only from the boles. We investigated (1) whether the degree of crown loss and the extent of epicormic branching were independent; and (2) whether epicormic branching differed by tree size. The...

The National Forest Management Act (1976) recognizes the importance of maintaining species and community diversity on National Forest System (NFS) lands as a critical component of our ecological and cultural heritage. Monitoring is required of land management to assess the success of management activities in meeting legal, regulatory, and policy objectives, including sustaining populations of native and desired nonnative species. The Multiple Species Inventory and Monitoring (MSIM) protocol is intended to serve as a consistent and efficient method for obtaining basic presence/absence data...

Using a qualitative aproach, the authors tested a crime typology developed for tourism destinations in a U.S. National Forest recreation setting. Specific objectives were to classify the attributes of crime and violence, examine the effects of crime and violence on visitor demand, and suggest methods of prevention and recovery. A key modification to the crime typology prior to data collection was to anchor it to crime- and violence-activity categories revealed from an earlier study. Several recommendations are given, with the understanding that they derived from the first run of the crime...

We tested three disturbance hypotheses in young conifer plantations: H1: soil compaction and removal of surface organic matter produces sustained changes in microbial community size, activity, and structure in mineral soil; H2: microbial community characteristics in mineral soil are linked to the recovery of plant diversity; and H3: community responses are strongly modified by regional climate. Microbial biomass, respiration, carbon utilization, and phospholipid fatty acids were compared at two subtropical installations and one Mediterranean-type climate installation of the North American...

Santiago, Chile's semi-arid climate and urbanized environment poses a severe limitation for the establishment and maintenance of urban forests. Municipalities, or comunas, are the main stakeholders in the management of Santiago's public urban forests. A tenable hypothesis would be that as the socioeconomic level of a comuna increases, the better the condition of a comuna's urban forest. Unfortunately, there is little comprehensive information on management, public expenditure, and structure of Santiago's public and private urban forests. To examine this hypothesis, Santiago was divided...