Treesearch

Forest health is affected by multiple factors, including topography, climate, and soil characteristics, as well as pests, pathogens, competitive interactions, and anthropogenic deposition. Species within a stand may respond differently to site factors depending on their physiological requirements for growth, survival, and regeneration. We determined optimal ranges of topographic (elevation, aspect, slope gradient), climatic (average temperature for January, July, and May to September; annual and May to September precipitation), and soil (pH, percent clay, percent coarse sand, permeability,...

This paper examines laws, policies, organizations and other governance elements and arrangements that influence forest conservation and sustainable resource management in the U.S. through a set of 10 Indicators associated with Criterion Seven of the Montréal Process Criteria and Indicators Framework. The applicability and utility of these indicators as a measure of forest governance at the national level is examined and associated quantitative and qualitative data are presented and discussed. In the U.S., a broad range of laws governs public lands, dictating management processes and...

Premise of research. Tropical epiphytes are susceptible to climatic changes, as evidenced by documented population declines, range contractions, and range shifts; however, physiological changes in individual plants may also be indicative of deteriorating climate conditions. Consequently, physiological analyses of tropical epiphytes whose natural habitats are constrained by climatic conditions are warranted to evaluate their responses to potential changes in these conditions, to assess their vulnerability, and to guide conservation actions. Methodology. Here we investigate photosynthetic...

Amazonia has experienced large-scale regional droughts that affect forest productivity and biomass stocks. Space-borne remote sensing provides basin-wide data on impacts of meteorological anomalies, an important complement to relatively limited ground observations across the Amazon’s vast and remote humid tropical forests. Morning overpass QuikScat Ku-band microwave backscatter from the forest canopy was anomalously low during the 2005 drought, relative to the full instrument record of 1999–2009, and low morning backscatter persisted for 2006–2009, after which the instrument failed. The...

Climate change in the western United States has increased the frequency of extreme fire weather events and is projected to increase the area burned by wildfire in the coming decades. This changing fire regime, coupled with increased high-severity fire risk from a legacy of fire exclusion, could destabilize forest carbon (C), decrease net ecosystem exchange (NEE), and consequently reduce the ability of forests to regulate climate through C sequestration. While management options for minimizing the risk of high-severity fire exist, little is known about the longer-term carbon consequences of...

Landscape values mapping has been widely employed as a form of public participation GIS (PPGIS) in natural resource planning and decision-making to capture the complex array of values, uses, and interactions between people and landscapes. A landscape values typology has been commonly employed in the mapping of social and environmental values in a variety of management settings and scales. We explore how people attribute meanings and assign values to special places on the Olympic Peninsula (Washington, USA) using both a landscape values typology and qualitative responses about residents’...

The perhumid coastal temperate rainforest (PCTR) of southeast Alaska has some of the densest soil organic carbon (SOC) stocks in the world (>300 Mg C ha-1) but the fate of this SOC with continued warming remains largely unknown. We quantified dissolved organic carbon (DOC) and carbon dioxide (CO2) yields from four different wetland types (rich fen, poor fen, forested wetland and cedar wetland) using controlled laboratory incubations of surface (10 cm) and subsurface (25 cm) soils incubated at 8 and 15 °C for 37 weeks. Furthermore, we used fluorescence characterization of DOC and laboratory...

The goal of this study was to use watershed characteristics derived from light detection and ranging (LiDAR) data to predict stream biogeochemistry in Perhumid Coastal Temperate Rainforest (PCTR) watersheds. Over a 2-day period, we sampled 37 streams for concentrations of dissolved C, N, P, major cations, and measures of dissolved organic matter quality (specific ultraviolet absorbance, SUVA254) and bioavailability. Random forest – classification and regression tree analysis showed that aboveground biomass and structure and watershed characteristics, inclusive of mean watershed slope and...

Large areas of forest plantations have been developed in China. It is important to evaluate the soil fauna in plantations and the conditions needed for their recovery in view of the large areas of plantations in China. Three Pinus tabulaeformis forests, a 26-year-old plantation (P26) and a 45-year-old plantation (P45), exposed to clear-cutting before plantation, and an 80–260-year-old natural forest (N260), were chosen to study the effects of different forest ages/types on Collembola community in the litter and soil layers during 2008 and 2009. Soil conditions in P26 and P45 were significan...

The sound of burning stems and leaves filled our ears and smoke swirled as we marched into the longleaf pine forest to assess the experimental burn. As we walked over the ash of burned vegetation, seedbanks and plant parts lay beneath our feet waiting to grow. But what we couldn’t see were the arthropods fleeing the fire. How are these invertebrates adapted to fire? They probably smell it coming, but do they feel the heat or see the smoke? Do they hear the noise that we hear as we near the flames?