Treesearch

Microwave-assisted liquefaction of bamboo in glycerol, polyethylene glycerol (PEG), methanol, ethanol, and water were comparatively investigated by evaluating the temperature-dependence for conversion and liquefied residue characteristics. The conversion for the liquefaction in methanol, ethanol, and water increased with an increase in reaction temperature, while that for liquefaction in glycerol and PEG was converse. The results of Fourier transform-infrared spectra for the liquefied residues revealed that cellulose was the main resistance to bamboo liquefaction in methanol, ethanol, and...

Light Detection and Ranging (LiDAR) has demonstrated potential for forest inventory at the individual-tree level. The aim in this study was to predict individual-tree height (Ht; m), basal area (BA; m2), and stem volume (V; m3) attributes, imputing Random Forest k-nearest neighbor (RF k-NN) and individual-tree-level-based metrics extracted from a LiDAR-derived canopy height model (CHM) in a longleaf pine (Pinus palustris Mill.) forest in southwestern Georgia, United States. We developed a new framework for modeling tree-level forest attributes that comprise 3 steps: (i) individual tree...

Forest fuel moisture is an important factor for wildland fire behavior. Predicting future wildfire trends and controlled burned conditions is essential to effective natural resource management, but the associated effects of forest fuel moisture remain uncertain. This study investigates the responses of dead forest fuel moisture to climate change in the continental United States, one of the global regions with frequent wildfire and controlled burning activities. Moisture content was calculated for dead fuels with 1‐ and 1000‐hr lags (MC1 and MC1000) using the algorithms from the U.S....

Understanding fine-scale variability in understory fuels is increasingly important as physics-based fire behavior modelsdrive needs for higher-resolution data. Describing fuelbeds 3Dly is critical in determining vertical and horizontal distributions offuel elements and the mass, especially in frequently burned pine ecosystems where fine-scale fuels arrangement drives fire intensity and resulting fire effects. Here, we describe research involving the use of highly resolved 3D models. We create fuelbeds using individual grass, litter, and pinecone models designed from field measurements....

Fire and forest disease have significant ecological impacts, but the interactions of these two disturbances are rarely studied. We measured soil C, N, Ca, P, and pH in forests of the Big Sur region of California impacted by the exotic pathogen Phytophthora ramorum, cause of sudden oak death, and the 2008 Basin wildfire complex. In Big Sur, overstory tree mortality following P. ramorum invasion has been extensive in redwood and mixed evergreen forests, where the pathogen kills true oaks and tanoak (Notholithocarpus densiflorus). Sampling was conducted across a full-factorial combination of...

Sudden oak death, caused by Phytophthora ramorum, has killed millions of oak and tanoak in California since its first detection in 1995. Despite some localized small-scale management, there has been no large-scale attempt to slow the spread of the pathogen in California. Here we use a stochastic spatially-explicit model parameterized using data on spread of P. ramorum to investigate whether and how the epidemic can be controlled. We find that slowing the spread of P. ramorum is now not possible, and has been impossible for a number of years. However, despite extensive cryptic (i.e....

The challenges posed by observing host-pathogen-environment interactions across large geographic extents and over meaningful time scales limit our ability to understand and manage wildland epidemics. We conducted a landscape-scale, longitudinal study designed to analyze the dynamics of sudden oak death (an emerging forest disease caused by Phytophthora ramorum) across hierarchical levels of ecological interactions, from individual hosts up to the community and across the broader landscape. From 2004 to 2011, we annually assessed disease status of 732 coast live oak, 271 black oak, and 122...

1. Organic matter decomposition is the main process by which carbon (C) is lost from terrestrialecosystems, and mycorrhizal associations of plants (i.e. arbuscular mycorrhizas (AM) and ectomycorrhizas(ECM)) may have different indirect effects on this loss pathway. AM and ECM plants differin the soil decomposers they promote and the quality of litter they produce, which may result indifferent patterns of organic matter decomposition, and hence, soil C loss.2. To determine how mycorrhizal associations indirectly affect decomposer activity, we collectedsoils and litters from four AM and four...

Fire and resource managers of the southern Appalachian Mountains, USA, have many questions about the use of prescribed fire and mechanical treatments to meet various land management objectives. Three common objectives include restoration to an open woodland, oak regeneration, and fuel reduction. This paper provides information about reaching each of these three management objectives by using prescribed burning (B), mechanical fuel reduction (M), and a combination of both fire and mechanical treatment (MB). The southern Appalachian site of the National Fire and Fire Surrogate study has been...