Treesearch

The global spread of the fungal pathogen Batrachochytrium dendrobatidis (Bd) has led to widespread extirpation of amphibian populations. During an intervention aimed at stabilizing at-risk populations, we treated wild-caught Cascades frogs Rana cascadae with the antifungal drug itraconazole. In fall 2012, we collected 60 recently metamorphosed R. cascadae from 1 of the 11 remnant populations in the Cascades Mountains (CA, USA). Of these, 30 randomly selected frogs were treated with itraconazole and the other 30 frogs served as experimental controls; all were released at the capture site....

Competitive interactions with Barred Owls (Strix varia) are an important factor contributing to the decline of the Northern Spotted Owl (Strix occidentalis caurina) population. Understanding the degree of similarity in fine-scale habitat associations for Spotted Owls and Barred Owls will help land managers evaluate whether there are specific vegetation conditions that could favor Spotted Owls over Barred Owls. From March 2004 to September 2006, I tracked 14 radio-tagged Barred Owls in the Okanogan-Wenatchee National Forest in the eastern Cascade Range, Washington. I analyzed forest...

Hydroregimes of ephemeral wetlands affect reproductive success of many amphibian species and are sensitive to altered weather patterns associated with climate change.We used 17 years of weekly temperature, precipitation, and waterdepth measurements for eight small, ephemeral, groundwaterdriven sinkhole wetlands in Florida sandhills to develop a hydroregime predictive model. To illustrate its utility for climate-change planning, we forecasted weekly wetland water-depths and hydroperiods (2012–2060) using our model and downscaled climate data from the CSIRO Mk3.5 Global Circulation Model...

Four general-use insecticides (Astro, Onyx, Dominion Tree & Shrub, and Xytect 2F) were evaluated for their effectiveness at preventing attacks by the southern pine beetle (SPB) (Dendroctonus frontalis) and the small southern pine engraver (Ips avulsus) using a previously developed small-bolt method. Evaluations were conducted between 58 and 126 days post treatment. Southern pine beetles from New Jersey and Mississippi, U.S., were evaluated using a mixture of field and laboratory small-bolt trials; beetle origina did not appear to affect results.

Although short-rotation woody crop biomass production technology has demonstrated a promising potential to supply feedstocks for bioenergy production, the water and nutrient processes in the woody crop planation ecosystem are poorly understood. In this study, a computer model was developed to estimate the dynamics of water and nitrogen (N) species (e.g., NH4–N, NO3–N, particulate organic N, and soluble organic N [SON]) in a woody crop plantation using STELLA (Structural Thinking and Experiential Learning Laboratory with Animation) software. A scenario was performed to estimate diurnal and...

Relative to vascular plants, little is known about what factors control bryophyte communities or how they respond to successional and environmental changes. Bryophytes are abundant in boreal forests, thus changes in moss community composition and functional traits (for example, moisture and nutrient content; rates of photosynthesis and respiration) may have important consequences for ecosystem processes and microfaunal communities. Through synthesis of previous work and new analyses integrating new and published data from a long-term successional gradient in the boreal forest of northern...

Ponderosa pine (Pinus ponderosa) is among the most broadly distributed conifer species of western North America, where it possesses considerable ecological, esthetic, and commercial value. It exhibits complicated patterns of morphological and genetic variation, suggesting that it may be in the process of differentiating into distinct regional lineages. A robust analysis of genetic variation across the ponderosa pine complex is necessary to ensure the effectiveness of management and conservation efforts given the species’ large distribution, the existence of many isolated disjunct population...

The pattern of forest land clearing in a region can be viewed as a gauge of sustainable (or unsustain-able) use of agricultural and forest resources. In this study we examine the geographical distribution ofland clearing potential in the Canadian agriculture–forestry interface and propose a new landscape-scaleindicator that quantifies this potential. We consider the possibility that forested land will be cleared foragriculture as a trade-off between the land’s capacity to support agriculture and its comparative valueif it remains forested. However, this trade-off is complicated by the...

There is an interest in restoring longleaf pine (Pinus palustris Mill.) across its native range in the southeastern United States, and establishment of longleaf pine on much of its original range requires artificial regeneration and management of competing vegetation after planting. In Louisiana, two fertilization levels (No or Yes [36 kg/ha nitrogen and 40 kg/ha phosphorus]) in combination with three vegetation treatments (check, five prescribed fires [PFs], or multiyear vegetation control [IVM]) were applied to longleaf pine plantings established in a randomized complete block factorial...

The spatial distribution of shallow landslides in steep forested mountains is strongly controlled by aboveground and belowground biomass, including the distribution of root cohesion. While remote sensing of aboveground canopy properties is relatively advanced, estimating the spatial distribution of root cohesion at the forest landscape scale remains challenging. We utilize canopy height information estimated using lidar (light detecting and ranging) technology as a tool to produce a spatially distributed root cohesion model for landslide hazard prediction. We characterize spatial patterns...