The effects of extreme rainfall events on carbon release from biological soil crusts covered soil in fixed sand dunes in the Tengger Desert, northern China

In May to August of 2011, we assessed the effects of extreme rainfall （quantity and intensity） events on the carbon release from soils covered by different types of biological soil crusts （BSCs） in fixed sand dunes in the Tengger Desert, northern China. A Li-6400-09 Soil Chamber was used to measure the respiration rates of the BSCs immediately after the rainfall stopped, and continued until the respiration rates of the BSCs returned to the pre-rainfall basal rate. Our results showed that almost immediately after extreme rainfall events the respiration rates of algae crust and mixed crust were significantly inhibited, but moss crust was not significantly affected. The respiration rates of algae crust, mixed crust, and moss crust in extreme rainfall quantity and intensity events were, respectively, 0.12 and 0.41 μmolCO2/（m2.s）, 0.10 and 0.45 gmolCO2/（m2·s）, 0.83 and 1.69 gmolCO2/（m2.s）. Our study indicated that moss crust in the advanced succession stage can well adaot to extreme rainfall events in the short term.

Initial carbon release characteristics, mechanisms and denitrification performance of a novel slow release carbon source

External carbon source addition is one of the effective methods for the treatment of wastewater with low carbon to nitrogen ratio(C/N). Compared with fast-release liquid carbon sources, slow-release solid carbon sources are more suitable for the denitrification process. A novel slow-release solid carbon source(corncob-polyvinyl alcohol sodium alginatepoly-caprolactone, i.e. CPSP) was prepared using corn cob(CC) and poly-caprolactone with polyvinyl alcohol sodium alginate as hybrid scaffold. The physical properties and carbon release characteristics of CPSP and three other carbon sources were compared. CPSP had stable framework and good carbon release performance, which followed the second order release equation. The formic acid, acetic acid, propionic acid and butyric acid released from CPSP accounted for 8.27% ± 1.66 %, 56.48% ± 3.71 %, 18.46% ± 2.69% and 16.79% ± 3.02% of the total released acids respectively. The start-up period of CPSP was shorter than that of the other carbon sources in denitrification experiment, and no COD pollution was observed in the start-up phase(25–72 h) and stable phase(73–240 hr). The composition and structure of the dissolved organic compounds released by CPSP and other carbon sources were analyzed by UV-Vis absorption spectroscopy and three-dimensional fluorescence spectroscopy,which indicated that CPSP was more suitable for denitrification than the other studied carbon sources.

Emerging glacier forelands alter carbon dynamics on the Tibetan Plateau

The critical challenge of ongoing climate warming is resulting in glacier melting globally,a process accompanied by the formation of substantial glacier forelands.This phenomenon emerges as a pivotal area of study,especially in the Tibetan Plateau(TP),known as the Third Pole and the Asian Water Tower.In particular,the rapid retreat of temperate glaciers in the southeastern TP has led to the formation of expansive glacier forelands.These forelands are not merely evidence of climate shifts but are also key areas for transformative carbon dynamics.Moreover,the newly exposed land surface actively adjusts the balance of dissolved organic carbon,especially in meltwater,and influences the release of greenhouse gases from a range of sources including glacial lakes,subglacial sediments,and supraglacial/proglacial rivers.These processes play a crucial role in the dynamics of atmospheric carbon dioxide.Drawing from our intensive and detailed observations over several years,this perspective not only emphasizes the importance of the underexplored impact of glacier forelands on carbon cycles but also opens a window into understanding potential future trajectories in a warming world.

Carbon dioxide release due to change in land use in China mainland

The carbon pool and emission of carbon dioxide from terrestrial ecosystems in Chinahave been estimated. The carbon pool is 2.51×10￣9-25.2×10￣9 ton C in vegetation, and 49. 7×10￣9ton C in soil. The carbon dioxide release from terrestrial ecosystems is 0.0317× 10￣9- 0. 195× 10￣9ton C due to changes in land-use in recent years, mainly caused by deforestation and degradation ofgrassland. This carbon release due to changes in land-use is approximately 17% of the current carbondioxide emission from fossil fuel combustion and cement production in China. As compared withthe global carbon pool, the carbon pool in vegetation and in soil in China are 1.8% and 3.3% ofthe global figures, respectively.

Effects of Exogenous Carbon Monoxide Releasing Molecules on the Development of Zebrafish Embryos and Larvae

The use of exogenous carbon monoxide releasing molecules（CORMs）provides promise for clinical application;however,the hazard potential of CORMs in vivo remains poorly understood.The developmental toxicity of CORM-3 was investigated by exposure to concentrations ranging from 6.25 to400μmol/L during 4-144 h post fertilization.Toxicity endpoints of mortality,spontaneous movement,heart rate,hatching rate,malformation,body length,and larval behavior were measured.

Long-term Decomposition Process of the Leaf Litter, Carbon and Nitrogen Dynamics under Different Forest Management in the Sierra de Francia, Salamanca, Spain

The dynamics of organic matter, carbon and nitrogen were studied during leaf decomposition over a three annual cycles period using the litterbag method at three permanently untilled and unfertilised plots. Our hypothesis is to determine if each litter type influences the decomposition and C and N releases from each other litter type （three plots and two species）. The main objective of this study is the comparison of decomposition dynamics in a climax forest with respect to that occurring in the chestnut managed plots on terrain suitable for oak to have further insight into the recycling of above ground organic matter and these two associated bioelements. As for the loss of dry matter, two-way analysis of variance, involving the treatment and year factors, revealed the existence of significant differences only for year, while no differences were observed for either treatment or interaction. At the end of the 2.4 years of the study, most of the treatment assays higher nitrogen concentrations than the initial ones were recorded. These three treatments the samplings prior to the last one revealed nitrogen concentrations higher than the initial ones, such that it may be concluded that the trend was towards an increase in concentration.

Permafrost carbon cycle and its dynamics on the Tibetan Plateau

Our knowledge on permafrost carbon(C)cycle is crucial for understanding its feedback to climate warming and developing nature-based solutions for mitigating climate change.To understand the characteristics of permafrost C cycle on the Tibetan Plateau,the largest alpine permafrost region around the world,we summarized recent advances including the stocks and fluxes of permafrost C and their responses to thawing,and depicted permafrost C dynamics within this century.We find that this alpine permafrost region stores approximately 14.1 Pg(1 Pg=1015g)of soil organic C(SOC)in the top 3 m.Both substantial gaseous emissions and lateral C transport occur across this permafrost region.Moreover,the mobilization of frozen C is expedited by permafrost thaw,especially by the formation of thermokarst landscapes,which could release significant amounts of C into the atmosphere and surrounding water bodies.This alpine permafrost region nevertheless remains an important C sink,and its capacity to sequester C will continue to increase by 2100.For future perspectives,we would suggest developing long-term in situ observation networks of C stocks and fluxes with improved temporal and spatial coverage,and exploring the mechanisms underlying the response of ecosystem C cycle to permafrost thaw.In addition,it is essential to improve the projection of permafrost C dynamics through in-depth model-data fusion on the Tibetan Plateau.