Treesearch

In the next few decades, longer growing seasons and rising carbon dioxide levels will increase yields of some crops, though those benefits will be progressively offset by extreme weather events. Though adaptation options can reduce some of the detrimental effects, in the long term, the combined stresses associated with climate change are expected to decrease agricultural productivity.

Torrefaction is a thermal process that improves biomass performance as a fuel by property enhancements such as decreased moisture uptake and increased carbon density. Most studies to date have used very small amounts of finely ground biomass. This study reports the testing of a crucible furnace retort that was fabricated to produce intermediate quantities of torrefied material and to allow processing of wood chips. Yields ranging from 51 to 96% were impacted to a greater extent by differences in temperature than time of treatment. Although temperature-control issues (gradients, slow...

When wood is kept dry, it can remain intact for millennia, as evidenced by numerous artifacts from ancient Egypt (1). However, when wood interacts with water, numerous problems arise that can cause the wood to become permanently damaged or destroyed completely. Wood exhibits swelling on moisture uptake and shrinkage on drying, and these cyclical moisture changes lead to internal stresses and can eventually form splits and checks within the wood. When there is an abundance of moisture in the wood, it is susceptible to microbial growth, fungal decay, corrosion of embedded metals, and...

Tree growth estimation is a challenging task as difficulties associated with data collection and inference often result in inaccurate estimates. Two main methods for tree growth estimation are diameter tape measurements and increment cores. The former involves repeatedly measuring tree diameters with a cloth or metal tape whose scale has been adjusted to give diameter readings directly. This approach has the advantage that diameters can be measured rapidly. However, because of the substantial error involved during tape measurements, negative diameter increments are often observed. Alternati...

Global sensitivity analysis is a useful tool to understand process-based ecosystem models by identifying key parameters and processes controlling model predictions. This study reported a comprehensive global sensitivity analysis for DRAINMOD-FOREST, an integrated model for simulating water, carbon (C), and nitrogen (N) cycles and plant growth in lowland forests. The analysis was carried out for multiple long-term model predictions of hydrology, biogeochemistry, and plant growth. Results showed that long-term mean hydrological predictions were highly sensitive to several key plant physiologi...

This periodic resource update provides an overview of forest resources in Florida based on an inventory conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program at the Southern Research Station in cooperation with the Florida Forest Service. Estimates are based on field data collected using the FIA annualized sample design and are updated yearly. The estimates presented in this update are for the measurement year 2012, with comparisons made to data reported in 2007. The sample plot population in Florida consists of 7,082 plots distributed across the State, of which...

Recent studies of the global diversity of the lichenized fungal family Graphidaceae suggest that there are a large number of species remaining to be discovered. No less than 640 species have been described since 2002, including 175 new species introduced in a collaborative global effort in a single issue in this journal. These findings suggest that the largest family of tropical crustose lichens may have an even higher number of species than Parmeliaceae. To estimate whether conserved tropical rain forest; (3) not well-studied but with increasing amount of molecular data becoming available;...

We present an updated 3-locus molecular phylogeny of tribe Ocellularieae, the second largest tribe within subfamily Graphidoideae in the Graphidaceae. Adding 165 newly generated sequences from the mitochondrial small subunit rDNA (mtSSU), the nuclear large subunit rDNA (nuLSU), and the second largest subunit of the DNA-directed RNA polymerase II (RPB2), we currently distinguish 218 species among the sequenced material, including the outgroup. This corresponds to almost half the species at this point recognized within this tribe. The newly generated sequences include 23 newly described...

We provide an updated skeleton phylogeny of the lichenized family Graphidaceae (excluding subfamily Gomphilloideae), based on three loci (mtSSU, nuLSU, RPB2), to elucidate the position of four new genera, Aggregatorygma, Borinquenotrema, Corticorygma, and Paratopeliopsis, as well as the placement of the enigmatic species Diorygma erythrellum, Fissurina monilifera, and Redingeria desseiniana. Based on the resulting topology, in addition to three tribes described previously, we recognize four further tribes in the subfamily Graphidoideae: Acanthothecieae Lumbsch, Kraichak & Lücking, Diploschi...

Two new genera and twelve new species of Graphidaceae are described from Puerto Rico. The two new genera, Borinquenotrema and Paratopeliopsis, are based on a combination of molecular sequence data and phenotype characters. Borinquenotrema, with the single new species B. soredicarpum, features rounded ascomata developing beneath and persistently covered with soralia and with an internal anatomy reminescent of Carbacanthographis; it is close to the tribe Ocellularieae. Paratopeliopsis, including the single new species P. caraibica, resembles a miniature Topeliopsis but differs in the...