The oxygen isotope composition in leaf water and organic compounds in different plant tissues is useful for assessing the physiological performance of plants in their environment, but more information is needed on Delta(18)O variation during a diel course. Here, we assessed Delta(18)O of the organic matter in leaves, phloem and xylem in stem segments, and fine roots of Ricinus communis during a full diel cycle. Enrichment of newly assimilated organic matter in equilibrium with leaf water was calculated by applying a nonsteady-state evaporative enrichment model. During the light period, Delta(18)O of the water soluble organic matter pool in leaves and phloem could be explained by a 27 per thousand enrichment compared with leaf water enrichment. Leaf water enrichment influenced Delta(18)O of phloem organic matter during the night via daytime starch synthesis and night-time starch remobilization. Phloem transport did not affect Delta(18)O of phloem organic matter. Diel variation in Delta(18)O in organic matter pools can be modeled, and oxygen isotopic information is not biased during transport through the plant. These findings will aid field studies that characterize environmental influences on plant water balance using Delta(18)O in phloem organic matter or tree rings.
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http://dx.doi.org/10.1111/j.1469-8137.2007.02007.x | DOI Listing |
Animal
December 2024
Department of Animal Science, Faculty of Veterinary Sciences, Universidad de Concepción, Campus Chillán, Chillán 3812120, Chile. Electronic address:
Climate change and food safety standards have intensified research into plant-based compounds as alternatives to dietary supplements in animal feed. These compounds can reduce enteric methane (CH) emissions and the formation of ruminal ammonia. This study investigated the effects of radiata pine bark extract (PBE) supplementation on CH production, ruminal fermentation parameters, and nutrient disappearance using the rumen simulation technique in diets with different forage-to-concentrate (F:C) ratios.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Earth and Environmental Sciences, California State University, Fresno, CA, United States of America.
Rice-crab co-culture is an environmentally friendly agricultural and aquaculture technology with high economic and ecological value. In order to clarify the structure and function of soil and water microbial communities in the rice-crab symbiosis system, the standard rice-crab field with a ring groove was used as the research object. High-throughput sequencing was performed with rice field water samples to analyze the species and abundance differences of soil bacteria and fungi.
View Article and Find Full Text PDFPLoS One
January 2025
School of Geography, Geology and the Environment, Institute for Environmental Futures, University of Leicester, Leicester, United Kingdom.
Dry evergreen Afromontane forests are severely threatened due to the expansion of agriculture and overgrazing by livestock. The objective of this study was to investigate the composition of woody species, structure, regeneration status and plant communities in Seqela forest, as well as the relationship between plant community types and environmental variables. Systematic sampling was used to collect vegetation and environmental data from 52 (20 m x 20 m) (400 m2) plots.
View Article and Find Full Text PDFArch Anim Nutr
January 2025
Institute of Animal Science, University of Bonn, Bonn, Germany.
Protein supply to ruminants relies mainly on the flow of microbial crude protein (MCP) from the rumen, which is commonly assumed to primarily depend on energy supply. This study evaluated this assumption with recent data and tested if ruminally fermented organic matter (FOM) was a better predictor of MCP flow than total-tract digestible organic matter (DOM) and if more variables could improve the prediction of MCP flow. A previously published data set was extended by additional studies resulting in a data set of 139 studies including 407 treatment means, typical to Central European rations.
View Article and Find Full Text PDFGlob Chang Biol
January 2025
Department of Environmental and Biological Sciences, Faculty of Science, Forestry and Technology, University of Eastern Finland, Kuopio, Finland.
Primary and secondary atmospheric pollutants, including carbon monoxide (CO), carbon dioxide (CO), nitrogen oxides (NO), ozone (O), sulphur dioxide (SO) and particulate matter (PM/PM) with associated heavy metals (HMs) and micro- and nanoplastics (MPs/NPs), have the potential to influence and alter interspecific interactions involving insects that are responsible for providing essential ecosystem services (ESs). Given that insects rely on olfactory cues for vital processes such as locating mates, food sources and oviposition sites, volatile organic compounds (VOCs) are of paramount importance in interactions involving insects. While gaseous pollutants reduce the lifespan of individual compounds that act as olfactory cues, gaseous and particulate pollutants can alter their biosynthesis and emission and exert a direct effect on the olfactory system of insects.
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