Treesearch

Mesoscale models are a class of atmospheric numerical model designed to simulate atmospheric phenomena with horizontal scales of about 2–200 km, although they are also applied to microscale phenomena with horizontal scales of less than about 2 km. Mesoscale models are capable of simulating wildland fire impacts on atmospheric flows if combustion byproducts (e.g., heat, smoke) are properly represented in the model. One of the primary challenges encountered in applying a mesoscale model to studies of fireperturbed flows is the representation of the fire sensible heat source in the model. Two...

We examined the importance of local habitat features on forest songbird distributions using a feature-dependent group framework that organizes species in relation to variable importance of species-habitat relationships. Habitat features included vegetation structure, floristics, and environmental (i.e., topography) classes. We also examined evidence for hierarchical habitat selection by assessing feature positioning within the ensemble structural models, Random Forests. From the 44 species examined, we distinguished 14 groups, comprising two to eight species per group, and examined...

1. Forest canopy structural complexity (CSC), an emergent ecosystem property, plays a critical role in controlling ecosystem productivity, resource acquisition and resource use-efficiency; yet is poorly characterized across broad geographic scales and is difficult to upscale from the plot to the landscape. 2. Here, we show that the relationship between canopy height and CSC can be explained using power laws by analysing lidar-derived CSC data from 17 temperate forest sites spanning over 17 degrees of latitude. Across three plant functional types (deciduous broadleaf, evergreen needleleaf...

Mercury (Hg) in forest runoff varies geographically and in relation to silvicultural practices. There is also considerable uncertainty about how forest management practices, such as residual biomass removal, affect Hg mobilization, and downgradient cumulative effects. In this study, total Hg, dissolved organic carbon (DOC), and sulfate (SO42−) mobilization in runoff were compared among unharvested and harvested hillslopes with and without residual biomass removal, and peat soil and invertebrate methylmercury (MeHg) concentrations were assessed in a down-gradient peatland. Using a before-aft...

Running buffalo clover (Trifolium stoloniferum; RBC), is a recently delisted stoloniferous species that occurs in several eastern states of the United States. Once thought to be extinct, RBC was rediscovered in West Virginia in 1985 and it is generally accepted that it requires moderate disturbance and filtered sunlight to grow. We studied how light availability and photosynthetic parameters are related to stolon production and overall plant growth. We sampled six occurrences in the USDA Forest Service Fernow Experimental Forest (Parsons, WV) in September 2018. For each occurrence, we...

The management of low-density savannah and woodland forests for carbon storage presents a mechanism to offset the expense of ecologically informed forest management strategies. However, existing carbon monitoring systems draw on vast amounts of either field observations or aerial light detection and ranging (LiDAR) collections, making them financially prohibitive in low productivity systems where forest management focuses on promoting resilience to disturbance and multiple uses. This study evaluates how UAS altitude and flight speed influence area-based aboveground forest biomass model...

Despite the importance of financial outcomes to stand-level forest management decision-making, long-term assessments are rare. We compared the quality and value of mixed, northern conifer (Picea–Abies–Tsuga) stands inMaine, USA, treated with a range of silvicultural systems and exploitive cuttings for 65 years. Ten replicated treatments — single-tree selection and uniform shelterwood systems, commercial clearcutting, fixed and guiding diameter-limit cutting, and no cutting — were assessed for quality and value of standing and harvested trees. Selection systems resulted in good tree quality...

Forested wetlands with high water tables are sensitive to disruption from harvesting yet support commercially desired tree species like northern white-cedar. Winter harvest was conducted in Maine, USA, to compare operational costs and productivity of cut-to-length harvesting in cedar (fragile soil) and non-cedar stands (mixedwood, sturdy soil), evaluate uncertainties in harvesting costs and influential factors, and forecast time for post-harvest recovery to pre-harvest volumes. Operational costs were calculated using detailed time and motion studies. Operational costs for the cedar stands...

Damage from infestations of Lymantria dispar L. in oak-dominated stands and southern pine beetle (Dendroctonus frontalis Zimmermann) in pine-dominated stands have far exceeded impacts of other disturbances in forests of the mid-Atlantic Coastal Plain over the last two decades. We used forest census data collected in undisturbed and insect-impacted stands combined with eddy covariance measurements made pre- and post-disturbance in oak-, mixed and pine-dominated stands to quantify how these infestations altered forest composition, structure and carbon dynamics in the Pinelands National...

Nut-bearing trees such as oaks (Quercus genus) and American chestnut (Castanea dentata, hereafter: chestnut) rely on scatter-hoarding animals for seed dispersal. With the pursuit of blight-resistant chestnuts for eventual reintroduction into eastern hardwood forests of the United States, it becomes important to understand how foraging preferences of avian seed-hoarders will influence chestnut dispersal in oak-dominated forests. Using six seed selection trials over three years and two "seasons" (early fall and late fall), we assess the relative seed preferences – when gathering seeds for...