Treesearch

Northern peatlands represent a long-term net sink for atmospheric CO2, but these ecosystems can shift from net carbon (C) sinks to sources based on changing climate and environmental conditions. In particular, changes in water availability associated with climate control peatland vegetation and carbon uptake processes. We examined the influence of changing hydrology on plant species abundance and ecosystem primary production in an Alaskan fen by manipulating the water table in field treatments to mimic either sustained flooding (raised water table) or drought (lowered water table) condition...

Perennial ryegrass (Lolium perenne L.) is a widely cultivated cool-season grass species because of its high quality for forage and turf. Susceptibility to freezing damage limits its further use in temperate zones. The objective of this study was to identify candidate genes significantly associated with winter survival and spring regrowth in a global collection of 192 perennial ryegrass accessions. Significant differences in winter survival (WS), percentage of canopy green cover (CGC), chlorophyll index (Chl), and normalized difference vegetation index (NDVI) were found among accessions....

Uncertainties in ecophysiological responses to environment, such as the impact of atmospheric and soil moisture conditions on plant water regulation, limit our ability to estimate key inputs for ecosystem models. Advanced statistical frameworks provide coherent methodologies for relating observed data, such as stem sap flux density, to unobserved processes, such as canopy conductance and transpiration. To address this need, we developed a hierarchical Bayesian State-Space Canopy Conductance (StaCC) model linking canopy conductance and transpiration to tree sap flux density from a 4-year...

The aim of this study was to determine the effect of agricultural land afforestation on soil characteristics. Two sites in two regions of the Czech Republic were evaluated, at lower as well as higher submountain elevations: in the regions of the Orlicke hory Mts. and Kostelec nad Cernymi lesy, afforested, arable and pasture lands were compared for basic chemical and physical characteristics. It was determined: pH, CEC, exchangeable nutrients, SOC, bulk density, volume density, porosity (differentiated by pore size), water conductivity and soil aggregate stability. This study demonstrated...

The US Department of Agriculture (USDA) Forest Service Calhoun Experimental Forest was organized in 1947 on the southern Piedmont to engage in research that today is called restoration ecology, to improve soils, forests, and watersheds in a region that had been severely degraded by nearly 150 years farming. Today, this 2,050-ha research forest is managed by the Sumter National Forest and Southern Research Station. In the early 1960s, the Calhoun Experimental Forest was closed as a base of scientific operations making way for a new laboratory in Research Triangle Park, NC. Many papers were...

The first full remeasurement of the annual inventory of the forests of Vermont and New Hampshire was completed in 2012 and covers nearly 9.5 million acres of forest land, with an average volume of nearly 2,300 cubic feet per acre. The data in this report are based on visits to 1,100 plots located across Vermont and 1,091 plots located across New Hampshire. Forest land is dominated by the maple/beech/birch forest-type group, which occupies 60 percent of total forest land area. Of the forest land, 64 percent consists of large diameter trees, 27 percent contains medium diameter trees, and 9...

Surface fuels were characterized in loblolly pine (Pinus taeda L.) plantations severely impacted by southern pine beetle (Dendroctonus frontalis Ehrh.) (SPB) outbreaks in the upper South Carolina Piedmont. Prescribed burning and mastication were then tested as fuel reduction treatments in these areas. Prescribed burning reduced fuelbed continuity by consuming litter (Oi layer), duff (Oe + Oa), and woody surface fuels (1-, 10-, and 100-h timelag size classes) immediately after the treatment. Total loading of 1- and 10-h fuels in burned stands (3.1 Mgha
-1) remained significantly lower than...

This field guide provides a framework for rapidly evaluating post-fire resilience to disturbance, or recovery potential, and resistance to invasive annual grasses, and for determining the need and suitability of the burned area for seeding. The framework identifies six primary components that largely determine resilience to disturbance, resistance to invasive grasses, and potential successional pathways following wildfire, as well as the information sources and tools needed to evaluate each component. The components are: (1) characteristics of the ecological site; (2) vegetation composition...

Wildfire management now emphasizes fire-adapted communities that coexist with wildfires, although it is unclear how communities will progress to this goal. Hazards research suggests that response to wildfire - specifically, rebuilding after fire - may be a crucial opportunity for homeowner and community adaptation. We explore rebuilding after the 2010 Fourmile Canyon Fire from Boulder, CO, that destroyed 165 homes, to better understand individual and community adaptation after wildfire. We examined changes in perception of fire risk and structural characteristics and vegetation mitigation...

Fire is an important disturbance in ecosystems across the eastern deciduous forests of North America (Brose et al. 2014). Matlack (2013) provided an interpretation of historical and contemporary fire in this region. Although we applaud Matlack for correcting simplistic assumptions that fire was ubiquitous and all plant communities need to burn regularly to maintain biodiversity, we believe his interpretation of the role of fire is erroneous on several counts. Most problematic is his statement “ . . . it seems prudent to limit the use of prescribed burning east of the prairie-woodland...