Treesearch

Although mean temperatures change annually and are highly correlated with elevation, the entire thermal regime on the Snoqualmie River, Washington, USA does not simply shift with elevation or season. Particular facets of the thermal regime have unique spatial patterns on the river network and at particular times of the year. We used a spatially and temporally dense temperature dataset to generate 13 temperature metrics representing popular summary measures (e.g., minimum, mean, or maximum temperature) and wavelet variances over each of seven time windows. Spatial stream-network models...

Abstract. Accurate vegetation mapping is critical for natural resources management, ecological analysis, and hydrological modeling, among other tasks. Remotely sensed multispectral and hyperspectral imageries have proved to be valuable inputs to the vegetation mapping process, but they can provide only limited vegetation structure characteristics, which are critical for differentiating vegetation communities in compositionally homogeneous forests. Light detection and ranging (LiDAR) can accurately measure the forest vertical and horizontal structures and provide a great opportunity for...

Restoring dead-wood amounts in forests is an increasingly and successfully applied conservation measure to counteract negative effects of intensive logging on biodiversity of saproxylic taxa. By contrast, if and how dead-wood addition benefits the vast number of non-saproxylic forest taxa, and how this varies with contextual factors like canopy openness, remains poorly understood. To enhance dead-wood addition strategies, it is thus important to understand how dead wood affects entire forests communities, not just saproxylic taxa. To untangle effects of dead-wood addition and canopy...

A population of Xiphinema chambersi from the root zone around live oak (Quercus virginiana Mill.) trees on Jekyll Island, GA, is described using both morphological and molecular tools and compared with descriptions of type specimens. Initially, because of a few morphological differences, this nematode was thought to represent an undescribed species. However, on further exami- nation, the morphometrics of the nematodes from live oak tend to agree with most of the morphometrics in the original description and redescription of X. chambersi except for few minor differences in V% relative to...

There are hundreds of wood-decay fungi in the Caribbean Basin, but relatively few of these are likely to grow on manmade structures built of wood or wood-composites. The wood-decay fungi of greatest concern are those that cause brown-rot, and especially brown-rot fungi that are resistant to copper-based wood preservatives. Some fungi that grow in the Caribbean and produce white-rot are able to grow in very hot and sometimes dry or salty environments; consequently, these fungi are sometimes observed on older man-made structures such as decks and posts. While the origin and history of the...

This study evaluated climate change impacts on stream flow, crop and sediment yields from three differ-ent tillage systems (conventional, reduced 1–close to conservation, and reduced 2–close to no-till), in theBig Sunflower River Watershed (BSRW) in Mississippi. The Soil and Water Assessment Tool (SWAT) modelwas applied to the BSRW using observed stream flow and crop yields data. The model was calibrated andvalidated successfully using monthly stream flow data (2001–2011).The model performances showed the regression coefficient (R2) from 0.72 to 0.82 and Nash–Sutcliffeefficiency index...

Chinese privet, Ligustrum sinense Lour., is an invasive shrub within riparian areas of the southeastern United States. Biological control is considered the most suitable management option for Chinese privet. The potential host range of the lace bug, Leptoypha hospita Drake et Poor, was evaluated on the basis of adult feeding and oviposition, combined oviposition–nymphal development no-choice tests, nymphal development no-choice tests, multiple generation comparison on Forestiera pubescens Nutt. and L. sinense no-choice tests, and multiple-choice tests with 45 plant species in 13 families....

While ecological succession shapes contemporary forest structure and dynamics, other factors like forest structure (dense vs. sparse canopies) and climate may alter structural trajectories. To assess potential sources of variation in structural trajectories, we examined proportional biomass change for a regionally dominant tree species, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), across vegetation zones representing broad gradients in precipitation and temperature with 3510 forest inventory plots in Oregon and Washington, USA. We found that P. menziesii biomass change decreased...

While excessive releases of greenhouse gases (GHG: N2O, CO2, CH4) to the atmosphere due to the burning of fossil fuel remains a concern, we also need to better quantify GHG emissions from natural systems. This study investigates GHG fluxes at the soil–atmosphere interface in a series of 7 stream reaches (riparian zones + exposed streambed sediment) across a range of geomorphic locations from headwaters reaches to lowland wetland reaches. When riparian fluxes (RZ) are compared to fluxes from in-stream locations (IS) under summer baseflow conditions, total CO2-equivalent (CO2eq) emissions...

Identification of the primary factors that influence the ecological distribution of species groups is important to managers of lowland-mountain forests in northern Iran. The aim of this study was to identify main ecological species groups, describe the site conditions associated with these species groups and the relationships between environmental factors and the distribution of ecological species groups using multi-variate analysis (Detrended correspondence analysis (DCA) and Canonical correspondence analysis (CCA)). For this purpose, 50 relevés (400 m2 each) were sampled using the Braun-...