Stable hydrogen and oxygen isotopic composition of bulk leaf water (deltaD(lw) and delta(18)O(lw)) in piñon pine (Pinus edulis and P. monophylla) and gas exchange parameters were measured under field conditions to examine the effects of seasonal moisture stress on leaf water isotopic enrichment. Study sites were located near the lower elevation limit for piñon in the southwestern USA. Leaf-level transpiration measurements were made four times daily in spring, summer and early autumn; simultaneously, leaf samples were collected for water extraction and stable isotope analysis. Diurnal variations in deltaD(lw) and delta(18)O(lw) values were small, especially when leaf water residence times (molar leaf water content divided by transpiration rate) were high. Stomatal conductance explained most of the variance (60%) in leaf water enrichment across the dataset. Observed leaf water enrichment was compared with predictions of steady-state and nonsteady-state models. Nonsteady-state predictions fit observations the best, although D enrichment was often lower than predicted by any model. Hydrogen isotope ratios of leaf water and cellulose nitrate were strongly correlated, demonstrating preservation of a leaf water signal in wood and leaf cellulose.
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http://dx.doi.org/10.1007/s00442-005-0164-7 | DOI Listing |
In 2019, diabetes mellitus affected 9.3% of the global population and accounted for one in nine adult deaths. Plant-based antioxidants neutralize harmful free radicals, mitigate oxidative stress, and significantly prevent diabetes and its complications.
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January 2025
Department of Industrial and Production Engineering, Bangladesh Army University of Science and Technology (BAUST), Saidpur, Cantonment, Bangladesh.
The use of composite materials, whether metallic or non-metallic, is becoming more popular nowadays because of some of their superior characteristics compared to the use of wood and metallic materials alone. From this perspective, a new natural fiber reinforced composite by varying the fiber orientation was developed in this study using coir and pineapple leaf fiber. This work uses the Taguchi method to investigate the different effects of control factors on mechanical and physical characteristics of the fabricated natural fiber-based composites.
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January 2025
Microbial Activity Unit, Department of Microbiology, Soils, Water and Environment Research Institute, Agricultural Research Center (ARC), Giza, 12619, Egypt.
L. faced a new and previously undocumented leaf blight disease for the first time. This disease manifests initially as small, circular, or irregular brown spots on older leaves, which gradually expand and merge into dark brownish blotches over time.
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January 2025
Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China; Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China; HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute, Futian, Shenzhen, Guangdong Province, China. Electronic address:
Recent studies have raised concerns about the potential toxicity of amorphous silica (SiO) nanoparticles (NPs). This investigation explores the uptake, transport, and transpiration of silica NPs in Apium graveolens var. secalinum.
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January 2025
Department of Geography, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia; Department of Environmental Science, Policy and Management, University of California at Berkeley, USA.
Wetland macrophytes play a critical role in the performance of treatment wetlands (TWs), primarily through nutrient uptake. However, this retention is temporary, as nutrients are released back into the water upon the decomposition of plant litter. The removal of stored nutrients from TWs can be efficiently achieved by harvesting plants during the peak of the growing season, albeit with significant ecological disturbance.
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