Complex spatiotemporal responses of global terrestrial primary production to climate change and increasing atmospheric CO2 in the 21st century.

Quantitative information on the response of global terrestrial net primary production (NPP) to climate change and increasing atmospheric CO2 is essential for climate change adaptation and mitigation in the 21st century. Using a process-based ecosystem model (the Dynamic Land Ecosystem Model, DLEM), we quantified the magnitude and spatiotemporal variations of contemporary (2000s) global NPP, and projected its potential responses to climate and CO2 changes in the 21st century under the Special Report on Emission Scenarios (SRES) A2 and B1 of Intergovernmental Panel on Climate Change (IPCC). We estimated a global terrestrial NPP of 54.

Effect of liquefaction temperature on hydroxyl groups of bio-oil from loblolly pine (Pinus taeda).

Loblolly pine was liquefied with ethylene glycol at 100, 150, 200 and 250 °C in order to analyze the effect of liquefaction temperature on hydroxyl groups of bio-oil, and to determine the source and variation of hydroxyl groups. The optimum temperature was found to be 150-200 °C. Hydroxyl number (OHN) of the bio-oil was ranged from 632 to 1430 mg KOH/g.

Near infrared spectroscopy calibration for wood chemistry: which chemometric technique is best for prediction and interpretation?

This paper addresses the precision in factor loadings during partial least squares (PLS) and principal components regression (PCR) of wood chemistry content from near infrared reflectance (NIR) spectra. The precision of the loadings is considered important because these estimates are often utilized to interpret chemometric models or selection of meaningful wavenumbers. Standard laboratory chemistry methods were employed on a mixed genus/species hardwood sample set.

Using dynamic Brownian bridge movement modelling to measure temporal patterns of habitat selection.

Accurately describing animal space use is vital to understanding how wildlife use habitat. Improvements in GPS technology continue to facilitate collection of telemetry data at high spatial and temporal resolutions. Application of the recently introduced dynamic Brownian bridge movement model (dBBMM) to such data is promising as the method explicitly incorporates the behavioural heterogeneity of a movement path into the estimated utilization distribution (UD).

The effects of exercise and diet on olfactory capability in detection dogs.

A previous work suggests that dietary fat may influence canine olfaction. The present study evaluated whether olfactory performance could be influenced by forms of dietary fat and exercise. Seventeen certified detection dogs were fed three different diets (high fat, low fat or high polyunsaturated fat) for 12 weeks.

The effect of thinning and clear-cut on changes in the relative abundance of root-feeding beetle (Coleoptera: Curculionidae) in Pinus taeda plantations in central Alabama and Georgia.

Background: Root-feeding beetles, particularly Hylastes spp., Hylobius pales Herbst and Pachylobius picivorus Germar, increase in abundance in stressed forest stands and vector Grosmannia and Leptographium spp. fungi, which contribute to southern pine decline (SPD) in the southeastern United States.

Modeling for proximate analysis and heating value of torrefied biomass with vibration spectroscopy.

The goal of this study was to characterize the changes in biomass with torrefaction for near infrared reflectance (NIR) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy for sweetgum, loblolly pine, and switchgrass. Calibration models were built for the prediction of proximate analysis after torrefaction. Two dimensional (2D) correlation spectroscopy between NIR and FTIR was found to precisely explain the depolymerization at key functional groups located within hemicellulose, cellulose, and lignin.

A structured approach to incidental take decision making.

Decision making related to incidental take of endangered species under U.S. law lends itself well to a structured decision making approach.

The effects of oil exposure and weathering on black-needle rush (Juncus roemerianus) marshes along the Gulf of Mexico.

Oil exposure has been shown to be detrimental to several salt marsh plants however little information is available for Juncus roemerianus. Thirty-two mesocosms were established with J. roemerianus sod and replicate marshes were exposed to Louisiana sweet crude oil to test oil dose (6, 12, and 24 L m⁻²) and weathering (oil weathered for 0 days, 3 days, and 3 weeks).

Warm is better: incubation temperature influences apparent survival and recruitment of wood ducks (Aix sponsa).

Avian parents that physically incubate their eggs must balance demands of self-maintenance with providing the proper thermal environment for egg development. Low incubation temperatures can lengthen the incubation period and produce changes in neonate phenotype that may influence subsequent survival and reproduction. We artificially incubated wood duck (Aix sponsa) eggs at three temperature regimes (low, 35.

Do nitrogen fertilizers stimulate or inhibit methane emissions from rice fields?

In rice cultivation, there are controversial reports on net impacts of nitrogen (N) fertilizers on methane (CH ) emissions. Nitrogen fertilizers increase crop growth as well as alter CH producing (Methanogens) and consuming (Methanotrophs) microbes, and thereby produce complex effects on CH emissions. Objectives of this study were to determine net impact of N fertilizers on CH emissions and to identify their underlying mechanisms in the rice soils.

China's crop productivity and soil carbon storage as influenced by multifactor global change.

Much concern has been raised about how multifactor global change has affected food security and carbon sequestration capacity in China. By using a process-based ecosystem model, the Dynamic Land Ecosystem Model (DLEM), in conjunction with the newly developed driving information on multiple environmental factors (climate, atmospheric CO2 , tropospheric ozone, nitrogen deposition, and land cover/land use change), we quantified spatial and temporal patterns of net primary production (NPP) and soil organic carbon storage (SOC) across China's croplands during 1980-2005 and investigated the underlying mechanisms. Simulated results showed that both crop NPP and SOC increased from 1980 to 2005, and the highest annual NPP occurred in the Southeast (SE) region (0.

Effect of nitrogen deposition on China's terrestrial carbon uptake in the context of multifactor environmental changes.

The amount of atmospheric nitrogen (N) deposited on the land surface has increased globally and by nearly five times in China from 1901 to 2005. Little is known about how elevated reactive N input has affected the carbon (C) sequestration capability of China's terrestrial ecosystems, largely due to the lack of reliable data on N deposition. Here we have used a newly developed data set of historical N deposition at a spatial resolution of 10 km x 10 km in combination with other gridded historical information on climate, atmospheric composition, land use, and land management practices to drive a process-based ecosystem model, the dynamic land ecosystem model (DLEM) for examining how increasing N deposition and its interactions with other environmental changes have affected C fluxes and storage in China's terrestrial ecosystems during 1901-2005.

Digestive utilization of ozone-exposed forage by rabbits (Oryctolagus cuniculus).

A mixture of common Southern Piedmont (USA) grassland species (Lolium arundinacea, Paspalum dilatatum, Cynodon dactylon and Trifolium repens) was exposed to O(3) [ambient (non-filtered; NF) and twice-ambient (2X) concentrations] and fed to individually caged New Zealand white rabbits (Oryctolagus cuniculus) in a digestibility experiment. Forages and feed refusals were analyzed for concentrations of total cell wall constituents, lignin, crude protein, and soluble and hydrolyzable phenolic fractions. Neutral detergent fiber and acid detergent fiber digestibility by rabbits were significantly lower for 2X than NF forage.

Improvement in HPLC separation of acetic acid and levulinic acid in the profiling of biomass hydrolysate.

5-Hydroxymethylfurfural (HMF) and furfural could be separated by the Aminex HPX-87H column chromatography, however, the separation and quantification of acetic acid and levulinic acid in biomass hydrolysate have been difficult with this method. In present study, the HPLC separation of acetic acid and levulinic acid on Aminex HPX-87H column has been investigated by varying column temperature, flow rate, and sulfuric acid content in the mobile phase. The column temperature was found critical in resolving acetic acid and levulinic acid.

Research gaps related to forest management and stream sediment in the United States.

Water quality from forested landscapes tends to be very high but can deteriorate during and after silvicultural activities. Practices such as forest harvesting, site preparation, road construction/use, and stream crossings have been shown to contribute sediment, nutrients, and other pollutants to adjacent streams. Although advances in forest management accompanied with Best Management Practices (BMPs) have been very effective at reducing water quality impacts from forest operations, projected increases in demand for forest products may result in unintended environmental degradation.

Predicting water quality in unmonitored watersheds using artificial neural networks.

Land use and land cover (LULC) play a central role in fate and transport of water quality (WQ) parameters in watersheds. Developing relationships between LULC and WQ parameters is essential for evaluating the quality of water resources. In this paper, we present an artificial neural network (ANN)-based methodology to predict WQ parameters in watersheds with no prior WQ data.

Ecology of root-feeding beetles and their associated fungi on longleaf pine in Georgia.

Root-feeding beetles, particularly of the curculionid subfamilies Scolytinae and Molytinae, are known to be effective vectors of Ophiostomatoid fungi. Infestation by these insects and subsequent infection by the Ophiostomatoid fungi may play an important role in accelerating symptom progression in pine declines. To examine the relationship between beetles and fungi in longleaf pine stands, root-feeding curculionids were collected in pitfall traps baited with ethanol and turpentine for 62 wk, and Ophiostomatoid fungi were isolated from their body surfaces.

Potential enzyme cost reduction with the addition of surfactant during the hydrolysis of pretreated softwood.

The potential economic benefits of surfactants addition on enzymatic hydrolysis of steam-exploded lodgepole pine (SELP) and ethanol-pretreated lodgepole pine (EPLP) were investigated in this study. Free cellulase readsorption on fresh substrate was used to recover and recycle cellulase enzymes during the hydrolysis of SELP and EPLP substrate. Supplementing Tween 80 during the hydrolysis could facilitate enzyme recycling for EPLP substrate.

Adsorption of cellulase on cellulolytic enzyme lignin from lodgepole pine.

Enzymatic hydrolysis of lignocellulosic materials is significantly affected by cellulase adsorption onto the lignocellulosic substrates and lignin. The presence of lignin plays an important role in lignocellulosic hydrolysis and enzyme recycling. Three cellulase preparations (Celluclast, Spezyme CP, and MSUBC) were evaluated to determine their adsorption onto cellulolytic enzyme lignin (CEL) from steam-exploded Lodgepole pine (SELP) and ethanol (organosolv)-pretreated Lodgepole pine (EPLP).

Evaluation of field and laboratory protocols used to detect avian influenza viruses in wild aquatic birds.

Careful selection and observance of standard field and laboratory protocols are critical for successful detection and characterization of avian influenza viruses (AIV) from wild birds. Cloacal swabs were collected from hunter-killed or nesting waterfowl and shorebirds from wildlife refuges in Alabama, Georgia, and Florida during 2006 to 2008. Swab samples were inoculated into embryonated eggs followed by hemagglutination (HA) test to determine the presence of hemagglutinating agents.

The potential of enzyme recycling during the hydrolysis of a mixed softwood feedstock.

Despite recent improvement in cellulase enzymes properties, the high cost associated with the hydrolysis step remains a major impediment to the commercialization of full-scale lignocellulose-to-ethanol bioconversion process. As part of a research effort to develop a commercial process for bioconversion of softwood residues, we have examined the potential for recycling enzymes during the hydrolysis of mixed softwood substrate pretreated by organosolv process. We have used response surface methodology to determine the optimal temperature, pH, ionic strength, and surfactant (Tween 80) concentration for maximizing the recovery of bound protein and enzyme activity from the residual substrates after hydrolysis.

Productivity of ephemeral headwater riparian forests impacted by sedimentation in the southeastern United States coastal plain.

Riparian forests serve an essential function in improving water quality through the filtering of sediments and nutrients from surface runoff. However, little is known about the impact of sediment deposition on productivity of riparian forests. Sediment inputs may act as a subsidy to forest productivity by providing additional nutrients for plant uptake or may act as a stress by creating anoxic soil conditions.

Detection and characterization of avian influenza and other avian paramyxoviruses from wild waterfowl in parts of the southeastern United States.

Cloacal swabs were taken from migratory hunter-killed, nonmigratory, nesting waterfowl and migratory shorebirds from wildlife refuges in Alabama, Georgia, and Florida during 2006 to 2008. Samples were processed in embryonated eggs followed by hemagglutination (HA), Directigen, and real-time reverse transcription-PCR tests. Sequence analysis of the hemagglutinin (H) gene of the H10N7 Alabama isolate revealed that it was closely related (98%) to recent isolates from Delaware and Canada, but only 90% related to an H10N7 isolated 30 yr ago.

Cutleaf coneflower (Rudbeckia laciniata L.) response to ozone and ethylenediurea (EDU).

Cutleaf coneflower (Rudbeckia laciniata L.) seedlings were placed into open-top chambers in May, 2004 and fumigated for 12 wks. Nine chambers were fumigated with either carbon-filtered air (CF), non-filtered air (NF) or twice-ambient (2x) ozone (O(3)).