Treesearch

Degraded red spruce (Picea rubens)-northern hardwood ecosystems are the focus of restoration efforts across high-elevation landscapes in the Central Appalachian region of the eastern United States. To promote ecosystem function and long-term sustainability of restored forests, it is important to understand the associated biota, including bird communities. Certain bird species could serve as ecological indicators, with potential applications for evaluating restoration efforts. However, contemporary and statistically rigorous studies of red spruce bird communities in this region are lacking,...

While it is known that modifying the hydroxyls in wood can improve the decay resistance; what is often missing in the literature is whether these modifications alter wood nanostructure, and how these changes correlate to the improved decay resistance. Here, we used small angle neutron scattering (SANS) to probe the effects of alkylene oxide modifications on wood nanostructure. Southern pine wood samples were chemically modified to various weight percentage gains (WPG) using four different alkylene oxides: propylene oxide (PO), butylene oxide (BO), epichlorohydrin (EpH), and epoxybutene...

Promoting sustainability of ecosystems and economic development is a dual national objective in China, as well as one of the sustainable development goals (SDGs) of the United Nations. The Three-River Headwaters Region, where a National Park initiative has been initiated in the pastoral region of the Qinghai-Tibetan Plateau, is one of the key pilot projects in China with sustainability targets for 2025 and 2035. This paper assesses the possibility of achieving established targets for the proportion of cultivated to available grassland. These targets consider both ecosystem protection and...

This study was aimed at improving the gas barrier property of sugarcane based LLDPE using cellulose nanocrystals (CNCs). Specifically, this study evaluated the effect of CNC content on the crystallinity, tortuosity factor, carbon dioxide permeability (PCO2), and/or oxygen permeability (PO2) of bio-LLDPE sheets and films. All nanocomposites showed considerable improvement in gas barrier irrespective of the CNC content. The PCO2 coefficient of LLDPE sheets decreased by 36% by adding 10 wt% of CNCs into the sheet. Similarly, a significant decline in both PO2 (about 50%) and PCO2 (about 33%)...

Wildfires can significantly impact air quality and human health. However; little is known about how different fuel bed components contribute to these impacts. This study investigates the air quality impacts of duff and peat consumption during wildfires in the southeastern United States; with a focus on the differing contributions of fine particulate matter less than 2.5 µm in size (PM2.5) and ozone (O3) to air quality episodes associated with the four largest wildfire events in the region during this century. The emissions of duff burning were estimated based on a field measurement of a...

Numerous devastating air pollution events from wildfire smoke occurred in this century in the western USA, leading to severe environmental consequences. This study projects future fire emissions in this region under climate change with a focus on comparing the relative contributions from future changes in burned area, fuel loading and fuel moisture. The three properties were projected using an empirical fire model, a dynamical global vegetation model and meteorological conditions respectively. The regional climate change scenarios for the western USA were obtained by dynamical downscaling...

The worldwide decline in bee populations is threatening the delivery of pollination services, thus leading to the development of pollinator restoration strategies. In the United States, one way to protect and restore bee populations is to use seed mixes composed of pollinator-friendly native plants to revegetate federal lands following disturbance. However, we lack information about which native plant species and mixes are best for bees. We assessed the attractiveness and use by bees of 24 native plant species that are standard for revegetation projects (focal plants) on national forest...

With the increasing frequency and severity of altered disturbance regimes in dry, western U.S. forests, treatments promoting resilience have become a management objective but have been difficult to define or operationalize. Many reconstruction studies of these forests when they had active fire regimes have documented very low tree densities before the onset of fire suppression. Building on ecological theory and recent studies, we suggest that this historic forest structure promoted resilience by minimizing competition which in turn supported vigorous tree growth. To assess these historic...

The Tension Zone (TZ) is a prominent Midwestern ecotone where the flora of two major forest types (Northern Mixed Forests and Southern Broadleaf Forests) commingle, striking diagonally across the states of Wisconsin and Minnesota. Here, we evaluated the TZ's original placement as demarcated by previous scholars relative to the synecological and autecological characteristics of witness trees from US Public Land Survey records. Witness trees were categorized by temperature and fire relations, point data analyzed in GIS, and spatial outputs compared with the original TZ. Our temperature-based...