Treesearch

Better knowledge of bird response to savanna and woodland restoration is needed to inform management of these communities. We related temporal and habitat variables to breeding demography and densities of the Eastern Wood-Pewee (Contopus virens) across a gradient of savanna, woodland, and forest. We determined nest success, clutch size, young fledged, and breeding densities and evaluated support for relationships with year, nest stage, date, nest height, tree cover, and percent forest in a 10-km radius. One hundred and twenty-eight of 310 nests (41.3%) fledged young. The most supported...

The assessment of water yield from hillslopes into streams is critical in managing water supply and aquatic habitat. Streamflow is typically composed of surface runoff, subsurface lateral flow, and groundwater baseflow; baseflow sustains the stream during the dry season. The Water Erosion Prediction Project (WEPP) model simulates surface runoff, subsurface lateral flow, soil water, and deep percolation. However, to adequately simulate hydrologic conditions with significant quantities of groundwater flow into streams, a baseflow component for WEPP is needed. The objectives of this study...

The use of renewable materials has received a great deal of attention over the last several decades due to the environmental impact and finite resources of petroleum and other non-renewable resources. Cellulose nanofibrils are a type of nanomaterial made from natural resources like wood and non-wood plants, and they are considering promising alternative to existing materials in numerous fields (Eichhorn et al., 2010). There are essentially four types of cellulose nanomaterials, including bacterial cellulose nanofibers, electrospun cellulose nanofibers, cellulose nanocrystals, and cellulose...

Hydrology drives the carbon balance of wetlands by controlling the uptake and release of CO2 and CH4. Longer dry periods in between heavier precipitation events predicted for the Everglades region, may alter the stability of large carbon pools in this wetland's ecosystems. To determine the effects of drought on CO2 fluxes and CH4 emissions, we simulated changes in hydroperiod with three scenarios that differed in the onset rate of drought (gradual, intermediate, and rapid transition into drought) on 18 freshwater wetland monoliths collected from an Everglades short-hydroperiod marsh....

Dutch Elm Disease (DED) is a vascular wilt disease of Ulmus species (elms) incited in North America primarily by the exotic fungus Ophiostoma novo-ulmi. The pathogen is transmitted via root grafts and elm bark beetle vectors, including the native North American elm bark beetle, Hylurgopinus rufipes and the exotic smaller European elm bark beetle, Scolytus multistriatus. The banded elm bark beetle, Scolytus schevyrewi, is an exotic Asian bark beetle that is now apparently the dominant elm bark beetle in the Rocky Mountain region of the USA. It is not known if S. schevyrewi will have an...

Efforts to conserve regional biodiversity in the face of global climate change, habitat loss and fragmentation will depend on approaches that consider population processes at multiple scales. By combining habitat and demographic modeling, landscape-based population viability models effectively relate small-scale habitat and landscape patterns to regional population viability. We demonstrate the power of landscape-based population viability models to inform conservation planning by using these models to evaluate responses of prairie warbler (Dendroica discolor) and wood thrush (Hylocichla...

The impact of foliar zinc fertilizer application on nut-bearing black walnut (Juglans nigra L.) trees was studied. Foliar sprays were applied three times per season on two cultivars during four growing seasons by wetting the foliage of the entire crown using a tank mix containing 500 ppm zinc, starting at leaf burst and continuing at 2 week intervals. The fertilizer treatment increased leaf zinc levels but did not impact nut production. Results from this trial indicate that the zinc standard for black walnut foliar nutrient analysis may be similar to the zinc standard of 25 to 100 ppm...

Greater sage-grouse (Centrocercus urophasianus) at the western edge of the Dakotas occur in the transition zone between sagebrush and grassland communities. These mixed sagebrush (Artemisia sp.) and grasslands differ from those habitats that comprise the central portions of the sage-grouse range; yet, no information is available on winter habitat selection within this region of their distribution. We evaluated factors influencing greater sage-grouse winter habitat use in North Dakota during 2005-2006 and 2006-2007 and in South Dakota during 2006-2007 and 2007-2008. We captured and radio-mar...

The Point Arena mountain beaver (Aplodontia rufa nigra) is federally listed as an endangered subspecies that is restricted to a small geographic range in coastal Mendocino County, California. Management of this imperiled taxon requires accurate information on its demography and vital rates. We developed noninvasive survey methods, using hair snares to sample DNA and to estimate abundance and survival at two sites, Kinney Beach and Alder Creek, within Manchester State Park. We extracted DNA and genotyped 371 hair samples resulting in the identification of a total of 54 individuals during...

The uncertainty associated with species distribution model (SDM) projections is poorly characterized, despite its potential value to decision makers. Error estimates from most modelling techniques have been shown to be biased due to their failure to account for spatial autocorrelation (SAC) of residual error. Generalized linear mixed models (GLMM) have the ability to account for SAC through the inclusion of a spatially structured random intercept, interpreted to account for the effect of missing predictors. This framework promises a more realistic characterization of parameter and predictio...