Soil respiration is a large carbon flux from terrestrial ecosystems to the atmosphere, and small variations in soil respiration can prominently influence the global carbon (C) cycle. The vegetation changes could directly affect soil respiration. The large-scale "Grain for Green" project carried out on the Loess Plateau, China has importantly affected the contribution of soil respiration to atmospheric carbon dioxide (CO). Therefore, it is important to study the effects of vegetation restoration on soil respiration. We selected four land-use types: crop, forest, shrub, and grassland in the Zhifanggou watershed to analyze variation in soil respiration during dry and rainy seasons. Furthermore, the source of CO emissions from soil respiration was identified using isotopes. The results showed that soil respiration in the rainy season was significantly higher than that in the dry season (P < .05). Soil respiration in the dry season was as follows: shrubland (1.04 μmol m s) > cropland (0.72 μmol m s) > forestland (0.44 μmol m s) > grassland (0.33 μmol m s). However, grass and forestland had significantly higher soil respiration than shrub and cropland in the rainy season (P < .05). Roots were the main source of soil respiration in cropland, which contributed >70% of CO emissions. Following revegetation, litter contributed more to soil respiration than roots or soil microorganisms at >68% of soil respiration. Our results provide a theoretical basis for assessing C balance in terrestrial ecosystems.
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http://dx.doi.org/10.1016/j.scitotenv.2019.135507 | DOI Listing |
J Agric Food Chem
January 2025
Institute of Science and Technology, Sao Paulo State University, Av. Três de Março, 511 - Alto da Boa Vista, 18087-180 Sorocaba, SP, Brazil.
Polymer-based herbicide nanocarriers have shown potential for increasing the herbicide efficacy and environmental safety. This study aimed to develop, characterize, and evaluate toxicity to target and nontarget organisms of natural-based polymeric nanosystems for glyphosate. Polymers such as chitosan (CS), zein (ZN), and lignin (LG) were used in the synthesis.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2025
Department of Civil, Geological, and Environmental Engineering, College of Engineering, University of Saskatchewan, 57 Campus Drive, Engineering Building, Saskatoon, SK, S7N 5A9, Canada.
Extending unfrozen water availability is critical for stress-tolerant bioremediation of contaminated soils in cold climates. This study employs the soil-freezing characteristic curves (SFCCs) of biostimulated, hydrocarbon-contaminated cold-climate soils to efficiently address the coupled effects of unfrozen water retention and freezing soil temperature on sub-zero soil respiration activity. Freezing-induced soil respiration experiments were conducted under the site-relevant freezing regime, programmed from 4 to - 10 °C at a seasonal soil-freezing rate of - 1 °C/day.
View Article and Find Full Text PDFNat Commun
January 2025
Climate and Ecosystem Sciences Division, Berkeley Lab, Berkeley, CA, USA.
Climate warming may accelerate decomposition of Arctic soil carbon, but few controlled experiments have manipulated the entire active layer. To determine surface-atmosphere fluxes of carbon dioxide and methane under anticipated end-of-century warming, here we used heating rods to warm (by 3.8 °C) to the depth of permafrost in polygonal tundra in Utqiaġvik (formerly Barrow), Alaska and measured fluxes over two growing seasons.
View Article and Find Full Text PDFEnviron Res
December 2024
Newe Ya'ar Research Center, Agricultural Research Organization, P.O. Box 1021, Ramat Yishay 30095, Israel. Electronic address:
In soil polluted with benzene, toluene, ethylbenzene, and xylenes (BTEX), oxygen is rapidly depleted by aerobic respiration, creating a redox gradient across the plume. Under anaerobic conditions, BTEX biodegradation is then coupled with fermentation and methanogenesis. This study aimed to characterize this multi-step process, focusing on the interactions and functional roles of key microbial groups involved.
View Article and Find Full Text PDFFront Plant Sci
December 2024
Jiangsu Key Laboratory of Sericultural and Animal Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.
Xylem plasticity is important for trees to coordinate hydraulic efficiency and safety under changing soil water availability. However, the physiological and transcriptional regulations of cambium on xylem plasticity are not well understood. In this study, mulberry saplings of drought-resistant Wubu and drought-susceptible Zhongshen1 were subjected to moderate or severe drought stresses for 21 days and subsequently rewatered for 12 days.
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