Treesearch

Carbonyl sulfide (OCS) has recently emerged as a tracer for terrestrial carbon uptake. While physiological studies relating OCS fluxes to leaf stomatal dynamics have been established at leaf and branch scales and incorporated into global carbon cycle models, the quantity of data from ecosystem-scale field studies remains limited. In this study, we employ established theoretical relationships to infer ecosystem-scale plant OCS uptake from mixing ratio measurements. OCS fluxes showed a pronounced diurnal cycle, with maximum uptake at midday. OCS uptake was found to scale with independent...

Very high resolution digital elevation models (DEM) provide the opportunity to represent the micro-level detail of topographic surfaces, thus increasing the accuracy of the applications that are depending on the topographic data. The analyses of micro-level topographic surfaces are particularly important for a series of geospatially related engineering applications. However, the generation of very high resolution DEM using, for example, LiDAR data is often extremely computationally demanding because of the large volume of data involved. Thus, we use a high-performance and parallel computing...

Few efforts have been made to quantify the amount and variety of deadwood in frequently burned ecosystems, particularly the longleaf pine (Pinus palustris Mill.) ecosystem of the southeastern United States. Moreover, comparisons of coarse woody debris between old-growth and secondary longleaf pine forests are lacking despite the widely recognized value of deadwood to biodiversity in many forest types. We measured standing and fallen deadwood in three old-growth and four mature (100–125 years-old) secondary forests in two landscapes characterized by either sandy or clayey soils within the...

1. The assessment of terrestrial wetland carbon stocks has improved greatly since the First State of the Carbon Cycle Report (CCSP 2007) because of recent national inventories and the development of a U.S. soils database. Terrestrial wetlands in North America encompass an estimated 2.2 million km2, which constitutes about 37% of the global wetland area, with a soil and vegetation carbon pool of about 161 petagrams of carbon that represents approximately 36% of global wetland carbon stock. Forested wetlands compose 55% of the total terrestrial wetland area, with the vast majority occurring...

The yeast microorganisms associated with Camponotus vicinus are discussed. Experiments where worker ants and larvae were fed holidic or nutrient deficient diets and then exposed to the yeast, Debaryomyces polymorphus showed that pupal weight was sometimes positively affected by exposure to D. polymorphus. It is speculated that the yeast may aid in more efficient assimilation of nutrients when fed nutrient-deficient diets, particularly diets lacking sterols.

Development of new drugs is one of the solutions to fight against the existing antimicrobial resistance threat. Cinnamaldehyde-amino acid Schiff base compounds, are newly discovered compounds that exhibit good antibacterial activity against gram-positive and gram-negative bacteria. Quantitative structure–activity relationship (QSAR) methodology was applied to explore the correlation between antibacterial activity and compound structures. The two best QSAR models showed R2 = 0.9354, F = 57.96, and s2 = 0.0020 against Escherichia coli, and R2 = 0.8946, F = 33.94, and s2 = 0.0043 against...

Plant-derived cellulose nanofibrils (CNFs) have shown reinforcing effects in polymer nanocomposites. However, freeze-dried CNFs are foam-like material, namely aerogel, that are challenging to disperse in a polymer matrix. In this work, a liquid infusion process was developed for a CNF/epoxy nanocomposite cross-linked foam structure with alterable properties without damaging the foam structure. Microstructures of CNF/epoxy composite foams with different formulations were evaluated using a scanning electron microscope. Surface morphology showed that the CNF cross-linked fibers were well...

Phosphorus (P) eutrophication in the aquatic system is a global problem. With a negative impact on health industry, food security, tourism industry, ecosystem health and economy. The sources of P include both point and nonpoint sources. Controlling P inflow from point sources to aquatic systems have been more manageable, however controlling nonpoint P sources especially agricultural sources remains a challenge. The forms of P include both organic and inorganic. Runoff and soil erosion are the major agents of translocating P to the aquatic system in form of particulate and dissolved P....

Plants modify development in response to external stimuli, to produce new growth that is appropriate for environmental conditions. For example, gravi‐stimulation of leaning branches in angiosperm trees results in modifications of wood development, to produce tension wood that pulls leaning stems upright. Here, we use gravi‐stimulation and tension wood response to dissect the temporal changes in gene expression underlying wood formation in Populus stems. Using time‐series analysis of seven time points over a 14‐d experiment, we identified 8,919 genes that were differentially expressed...

In two of our recent systems biology studies of forest trees we reconstructed gene networks active in wood tissue development for an undomesticated tree genus, Populus. In the first study, we used time series data to determine gene expression dynamics underlying wood formation in response to gravitational stimulus. In the second study, we integrated data from newly generated and publicly available transcriptome profiling, transcription factor binding, DNA accessibility and genome-wide association mapping experiments, to identify relationships among genes expressed during wood formation. We...