Treesearch

Symptoms of beech leaf disease (BLD), first reported in Ohio in 2012, include interveinal greening, thickening and often chlorosis in leaves, canopy thinning and mortality. Nematodes from diseased leaves of American beech (Fagus grandifolia) sent by the Ohio Department of Agriculture to the USDA, Beltsville, MD in autumn 2017 were identified as the first recorded North American population of Litylenchus crenatae (Nematology, 21, 2019, 5), originally described from Japan. This and other populations from Ohio, Pennsylvania and the neighbouring province of Ontario, Canada showed some differenc...

Large wildfires (>50,000 ha) are becoming increasingly common in semiarid landscapes of the western United States. Although fuel reduction treatments are used to mitigate potential wildfire effects, they can be overwhelmed in wind-driven wildfire events with extreme fire behavior. We evaluated drivers of fire severity and fuel treatment effectiveness in the 2014 Carlton Complex, a record-setting complex of wildfires in north-central Washington State. Across varied topography, vegetation, and distinct fire progressions, we used a combination of simultaneous autoregression (SAR) and random...

Cities across the world are undertaking ambitious projects to expand tree canopy by increasing the number of trees planted throughout public and private spaces. In epidemiological studies, greenspaces in urban environments have been associated with physical and mental health benefits for city dwellers. Greenworks Philadelphia is a plan to increase tree cover across Philadelphia (PA, USA) by the year 2025. We aimed to assess whether an increase in tree canopy or greenspace in Philadelphia could decrease mortality.We did a greenspace health impact assessment to estimate the annual premature...

The rapid loss of eastern hemlock (Tsuga canadensis) in the southern Appalachian Mountains due to hemlock woolly adelgid (Adelges tsugae, HWA) infestation has resulted in substantial changes to ecosystem structure and function. Several restoration strategies have been proposed, including silvicultural treatments that increase incident light in forest understories. We conducted a four-year manipulative field experiment on surviving mid-story hemlock trees to investigate the effects of release from light limitation on HWA infestation and physiological parameters, expecting that higher light...

The Latinx population is the largest growing minority population in the United States and is estimated to comprise 28% of the U.S. population by 2050. This continued growth is no longer due to foreign-born immigration, which accounted for 34% of all Latinx people in 2015, but rather to those born in the U.S., who comprised 66% of all Latinxs that year. Therefore, the current and future Latinx population consists of second-, third-, and fourth-generation Americans who report being fluent in English and Spanish, have higher levels of education, and earn higher incomes. As the Latinx populatio...

Top-down technical or engineered solutions to deal with flood control such as channelization are increasingly unaffordable. We explored how community leaders’ frame the concept of risk, particularly due to flooding, and documented bottom-up rather than top-down solutions within the context of Hurricane Maria and the current financial crisis. This research aimed to interview environmental conservation organizational leaders to assess the broader question of what makes San Juan livable, and the role that flooding risk management plays in defining livability. Their perception of bottom-up...

Human consumption of freshwater is now approaching or surpassing the rate at which water sources are being naturally replenished in many regions; creating water shortage risks for people and ecosystems. Here we assess the impact of human water uses and their connection to water scarcity and ecological damage across the United States; identify primary causes of river dewatering and explore ways to ameliorate them. We find irrigation of cattle-feed crops to be the greatest consumer of river water in the western United States; implicating beef and dairy consumption as the leading driver of...

Linking quickflow response to subsurface state can improve our understanding of runoff processes that drive emergent catchment behavior. We investigated the formation of nonlinear quickflows in three forested headwater catchments and also explored unsaturated and saturated storage dynamics, and likely runoff generation mechanisms that contributed to their formation. Our analyses focused on two reference watersheds at the Coweeta Hydrologic Laboratory (CHL) in western North Carolina, USA and one reference watershed at the Susquehanna Shale Hills Critical Zone Observatory (SHW) in Central...

September housing data were tepid, with several monthly declines in starts, permits, completions, and new single-family sales. Total private residential construction spending was minimally positive; conversely, single-family construction expenditures declined slightly on a monthly basis. All housing start data were positive on year-over-year starts. Housing under construction remained positive, except for yearly multifamily data. Single-family housing completions were negative on a month-over-month and positive on a yearly basis. Existing sales continued their stagnant trend, monthly and...