Treesearch

The influence of Leptographium terebrantis stem infection on constitutive and induced oleoresin and soluble phenolics in terminal shoots was assessed in a Pinus taeda plantation using three inoculum densities. The pathogen causes wilt disease by invading and colonizing root xylem tissues. We observed three levels of P. taeda defense in response to L. terebrantis during a two-year period interrupted by drought. Normal carbon allocation to growth was maintained and constitutive oleoresin production was observed at low and medium inoculum densities, with oleoresin induction observed among the...

Climate change and increases in the frequency and severity of climate-driven wildfires, particularly in the western United States, has serious ramifications for enhanced downwind reactive nitrogen (Nr) emissions, deposition, and critical load exceedances. Here we present a multi-decadal (2002−2021), harmonized model-data-driven study using the George Mason University North American Chemical Reanalysis (NACR) system and simulations including both “with-fire” and “without-fire” conditions to quantify the change in trends of fire activity and source contributions to total Nr emissions and...

Insect defoliation outbreaks are dynamic forest disturbances that alter species composition and carbon balance. In the Central Appalachian Mountains, U.S.A., the invasive spongy moth (SM, Lymantria dispar L., formerly called gypsy moth) has been spreading and impacting oak forests for 45 years, yet much about how its outbreaks compound the effects of native defoliator inhabitants remains unknown. We developed a model to simulate insect defoliation and project long-term consequences on forest biomass and composition. The model incorporates outbreak spatial dynamics derived from Landsat data...

Forest succession, or ecosystem process models, can aid in many land management decisions as they inherently incorporate ecological processes to predict how disturbances impact the resilience of the forest and its potential future structure. The landscape class of ecosystem process models are often ideal for management goals as they simulate individual tree species interactions through time at the landscape scale and offer a robust assortment of disturbance extensions. However, broad implementation and adoption are often limited as users must rebuild the landscape models for every new site...

Historically, oaks have dominated forests and woodlands in the eastern US, but oaks are being replaced by mesophytic tree species. Mesophication was likely triggered by moist, shaded conditions related to fire exclusion, and thus, moisture and fire have been the focus of prior research. However, forests undergoing mesophication also experience high soil nitrogen (N) availability, and timber harvests often create high-light conditions. Oaks may compete poorly with mesophytes in these resource-rich conditions due to their distinct strategies for growth and nutrient acquisition. Here, we...

Land cover and extreme weather events are closely connected to ecosystem services like water yield and carbon sequestration. Understanding how carbon and water respond to human disturbances is critical for managing these resources and realize desired ecosystem services at the national llevel. The monthly scale ecosystem model, Water Supply Stress Index (WaSSI), was tested and applied across Germany for mapping carbon and water balances from 2001 to 2019. We estimated that ecosystems in Germany generate 84.86 billion m3 of water yield and sequester 106.03 Tg of carbon annually on average....

The “Nature‐based Solutions” strategy for combatting global land degradation and climate change through forestation has drawn increasing concerns regarding its potential tradeoffs with water resources, especially in dry regions. China is “greening up” due to decades of large‐scale tree planting and ecological restoration campaigns. However, national‐level assessments of the individual and combined effects of forest cover and climate changes on water yield at a fine scale are still lacking. Here, we show several lines of evidence indicating that the unprecedented forestation has exacerbated...

Resource pulses are ecologically important events that occur in most ecosystems, yet most of our previous knowledge about their effects comes from relatively simple single pulse systems. In reality, many consumers likely attempt to track multiple, sometimes overlapping, resource pulses through space and time. Indeed, pulses of food resources at lower trophic levels have been shown to decouple the response of large omnivorous predators to pulses of vertebrate prey, with implications for predator–prey interactions more broadly. However, to date, the impact of these alternative food pulses on...

Density estimation is central to wildlife management efforts but can be challenging in anthropogenically‐dominated landscapes due to small parcel sizes, access restrictions, and limited green space. Reliable density estimates are especially important for managing white‐tailed deer ( Odocoileus virginianus ), whose high abundance in urbanized areas increases the need for accurate population assessments to guide management and reduce negative human–wildlife interactions. Herein, we evaluated (a) the use of a plot‐based spatial capture‐recapture sampling design to estimate deer density in...

Riparian forest buffers are used in the United States for multiple conservation, cultural, and socio-economic benefits. To date, no comprehensive national survey has been conducted on producers with riparian forest buffers, limiting understanding of how they establish, manage, and value these systems. The National Agroforestry Producer Survey was conducted to address this knowledge gap. The survey was completed by 5,682 producers with agroforestry (52% response rate). This study provides results from the 2,433 producers who reported using riparian forest buffers, one of the five agroforestr...