Treesearch

Urban public spaces impact communities’ quality of life. New parents seek the company of others at the park. Basketball players drop by a recreation center to see if there’s a pick-up game they can join. Children race to the playground after school to release pent-up energy with their neighborhood friends or join a community-provided after school program. A worker takes a quiet lunch break on a bench under the shade of a street tree. Neighbors convene in the community room of the local library for their monthly reading group, just after a nutrition class ends. These activities build...

Forest insects and pathogens have significant impacts on U.S. forests, annually affecting an area nearly three times that of wildfires and timber harvesting combined. However, coupled with these direct effects of forest insects and pathogens are the indirect impacts through influencing forest management practices, such as harvesting. In an earlier study, we surveyed private woodland owners in the northeastern U.S. and 84% of respondents indicated they intended to harvest in at least one of the presented insect invasion scenarios. This harvest response to insects represents a potentially...

Songbirds of many species acquire their songs by imitating the songs of conspecific singers. Conclusive evidence of such imitation comes from controlled laboratory studies, but such studies do not reveal when and where songbirds learn their songs under natural conditions. To determine the timing and location of song learning in a population of prairie warblers, we compared the songs of yearling prairie warblers of known hatching location to the songs of other birds in the yearlings' natal and first breeding areas. The comparisons yielded a likely model song (and model singer) for each of...

Green infrastructure (GI) and other stormwater management practices are commonly designed to reduce stormflow volume and pollutant loads by using infiltration, retention, and evapotranspiration to capture stormwater. Although these methods are be designed to reduce impacts of stormwater volumes and pollutant loads, they may not be designed to mitigate thermal load from stormwater runoff in urban areas. This review of literature identifies key drivers of stream temperature in urban streams, including heat transference from stormflow and effects of pipe networks and evapotranspiration on...

Over the past six years, inadvertent plant pathogen introductions into restorations plantings have stunned and frustrated vegetation ecologists. Sticky monkeyflower (Diplacus aurantiacus), toyon (Heteromeles arbutifolia), sages (Salvia spp.), and other common restoration plants have been found to harbor soilborne Phytophthora species, relatives of the sudden oak death pathogen (Phytophthora ramorum). Detections in native plant nurseries and restoration sites include new to the US Phytophthora species (Phytophthora tentaculata, P. quercina), new species (P. taxon agrifolia), and new...

Concentration-discharge (C-Q) relations can provide insight into the dynamic behavior of the Critical Zone (CZ), as C-Q relations integrate the spatial distribution and timing of watershed hydrogeochemical processes. This study blends geomorphologic analysis, C-Q relations and reactive-transport modeling using a rich dataset from an elevation gradient of eight watersheds in the Southern Sierra Nevada, California. We found that the CZ structure exerts a strong control on the C-Q relations, and on the hydrogeochemical behavior of headwater watersheds. Watersheds with thin regolith, a large...

Greenspace is increasingly examined as a low-cost way to increase standardized test scores in public schools. However, the evidence for this intervention is mixed. One potential explanation is the variety of ways that greenspace is measured using remotely sensed data. For instance, aggregate measures can be captured from tree, grass, and shrub cover classifications in high-resolution (1m2) land cover datasets or they can be measured with normalized difference vegetative index (NDVI) values from sensors at different resolutions (e.g., 30m2 or 250m2). In the current cross-sectional observatio...

Cross-site patterns for multiple sites tend to be more broadly applicable and more useful for constructing and constraining models. We examined cross-site patterns of Eucalyptus plantation response to water supply (including irrigation and 1/3 precipitation removal), mean annual temperature (MAT), vapor pressure deficit during the daytime (VPD), and nutrient addition in eight sites from the Brazil Eucalyptus Productivity Project (BEPP). Mean annual increment (MAI) for all treatments and sites varied from 12.7 to 37.3 Mg ha-1 yr-1 across a 1400 km latitudinal gradient where annual precipitat...

Human development and agriculture can have transformative and homogenizing effects on natural systems, shifting the composition of ecological communities towards non-native and native species that tolerate or thrive under human-dominated conditions. These impacts cannot be fully captured by summarizing species presence, as they include dramatic changes to patterns of species abundance. However, how human land use patterns and species invasions intersect to shape patterns of abundance and dominance within ecological communities is poorly understood even in well-known taxa.

Global ballast water management regulations aiming to decrease aquatic species invasion require actions that can increase shipping costs. We employ an integrated shipping cost and global economic modeling approach to investigate the impacts of ballast water regulations on bilateral trade, national economies, and shipping patterns. Given the potential need for more stringent regulation at regional hotspots of species invasions, this work considers two ballast water treatment policy scenarios: implementation of current international regulations, and a possible stricter regional regulation...