Treesearch

Identifying superior Salicaceae genotypes for afforestation and restoration activities in urban areas can greatly increase the provision of ecosystem services for long-term ecological sustainability. To address this opportunity, we collected native Populus L. (Salicaceae) and Salix L. (Salicaceae) scions from 3 sites on Staten Island, New York, and conducted a propagation study followed by greenhouse and nursery scale-up activities. Our objectives were to: 1) identify hormone treatments that enhanced root initiation and early growth of the native genotypes; 2) incorporate Salicaceae...

Many freshwater fish species are considered vulnerable to stream temperature warming associated with climate change because they are ectothermic, yet there are surprisingly few studies documenting changes in distributions. Streams and rivers in the U.S. Rocky Mountains have been warming for several decades. At the same time these systems have been experiencing an increase in the severity and frequency of wildfires, which often results in habitat changes including increased water temperatures. We resampled 74 sites across a Rocky Mountain watershed 17 to 20 years after initial samples to...

Freshwater ecosystems are warming globally from the direct effects of climate change on air temperature and hydrology and the indirect effects on near-stream vegetation. In fire-prone landscapes, vegetative change may be especially rapid and cause significant local stream temperature increases but the importance of these increases relative to broader changes associated with air temperature and hydrology are not well understood. We linked a spatially explicit landscape fire and vegetation model (FireBGCv2) to an empirical regression equation that predicted daily stream temperatures to...

Habitat fragmentation in aquatic systems has led to widespread isolation of stream fishes. Metapopulation theory predicts that persistence is directly related to local patch size and its characteristics, but because these relationships tend to be taxon-specific, empirical data are important. We assembled 246 observations of occurrence of westslope cutthroat trout (WCT), a taxon of concern in the western U.S. and Canada, in stream networks isolated for up to 100 years (median 40 years) above human-made barriers, mostly culverts, at road crossings within U.S. National Forests. We used...

Environmental DNA (eDNA) is increasingly applied as a highly sensitive way to detect aquatic animals non-invasively. However, distinguishing closely related taxa can be particularly challenging. Previous studies of ancient DNA and genetic diet analysis have used blocking primers to enrich target template in the presence of abundant, non-target DNA. Here we apply a blocking primer to increase the specificity of a TaqMan assay for eDNA detection of rare and endangered bull trout (Salvelinus confluentus) in the presence of the closely related (Salvelinus namaycush). We found that addition of...

The purpose of this study was to review scientific knowledge and model projections on vegetation vulnerability to climatic and other environmental changes in the Pacific Northwest, with emphasis on five major biome types: subalpine forests and alpine meadows, maritime coniferous forests, dry coniferous forests, savannas and woodlands (oak and juniper), and interior shrub-steppe. We started by reviewing and synthesizing the scientific literature on past and projected changes in atmospheric carbon dioxide concentrations and climate for the Pacific Northwest (and globally), and how these...

Managing wildland fire incidents can be fraught with complexity and uncertainty. Myriad human factors can exert significant influence on incident decision making, and can contribute additional uncertainty regarding programmatic evaluations of wildfire management and attainment of policy goals. This article develops a framework within which human sources of uncertainty in wildfire management can be classified and managed, specifically identifying social, institutional, and psychological factors that can affect wildland fire incident decision making. These factors are reviewed in the context...

We analyzed wildland fire occurrence and size data from Sardinia, Italy, and Corsica, France, to examine spatiotemporal patterns of fire occurrence in relation to weather, land use, anthropogenic features, and time of year. Fires on these islands are largely human caused and can be attributed to negligence, agro-pastoral land use, and arson. Of particular interest was the predictive value of a fire weather index (FWI) that is widely used by fire managers to alert suppression crews. We found that an increase in the FWI from 30 to 60 produced on average an approximate eightfold increase in...

Black ash wetlands are seriously threatened because of the invasive emerald ash borer (EAB). Wetland hydrology is likely to be modified following ash mortality, but the magnitude of hydrological impact following loss via EAB and alternative mitigation harvests is not clear. Our objective was to assess the water table response to simulated EAB and harvesting to determine if management actions will be needed to maintain ecosystem functions following EAB infestation. We applied four replicated treatments to 1.6 ha plots as follows: (1) control, (2) girdling of all black ash trees to simulate...

Trees serve important functions in riparian areas. Guidelines often suggest how riparian forests should be managed to sustain functions, including tree retention and increasing the component of conifers and later-successional species. While regeneration of early successional species is not discouraged, there is uncertainty about the ability to regenerate the latter along with more desirable species. We investigated the regeneration of species differing in successional status and growth forms under different amounts of residual basal area. The study was conducted in riparian sites in...