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The successful utilization of stable carbon isotope approaches in investigating forest carbon dynamics has relied on the assumption that the carbon isotope compositions (δ13C) therein have detectable temporal variations. However, interpreting the δ13C signal transfer can be challenging, given the complexities involved in disentangling the effect of a single environmental factor, the isotopic dilution effect from background CO2 and the lack of high-resolution δ13C measurements. In this study, we conducted continuous in situ monitoring of atmospheric CO2 (δ13Ca) across a canopy profile in an old-growth temperate forest in northeast China during the normal year 2020 and the wet year 2021. Both years exhibited similar temperature conditions in terms of both seasonal variations and annual averages. We tracked the natural carbon isotope composition from δ13Ca to photosynthate (δ13Cp) and to ecosystem respiration (δ13CReco). We observed significant differences in δ13Ca between the two years. Contrary to in 2020, in 2021 there was a δ13Ca valley in the middle of the growing season, attributed to surges in soil CO2 efflux induced by precipitation, while in 2020 values peaked during that period. Despite substantial and similar seasonal variations in canopy photosynthetic discrimination (Δ13Ccanopy) in the two years, the variability of δ13Cp in 2021 was significantly lower than in 2020, due to corresponding differences in δ13Ca. Furthermore, unlike in 2020, we found almost no changes in δ13CReco in 2021, which we ascribed to the imprint of the δ13Cp signal on above-ground respiration and, more importantly, to the contribution of stable δ13C signals from soil heterotrophic respired CO2. Our findings suggest that extreme precipitation can impede the detectability of recent photosynthetic δ13C signals in ecosystem respiration in forests, thus complicating the interpretation of above- and below-ground carbon linkage using δ13CReco. This study provides new insights for unravelling precipitation-related variations in forest carbon dynamics using stable isotope techniques. [ABSTRACT FROM AUTHOR]

An informationtized, digitalized, and intelligent emergency response mode is currently required in China to address the weaknesses and low efficiency in public health emergency management in the aspects of quick response mechanism, multi-department collaboration, and information interaction; this new mode can promote the response capabilities of China’s public security sector. A descriptive research method is adopted to analyze the status quo of public health emergency response systems and intelligent emergency response development in other countries, and summarize the requirements, current status, and main problems of health emergency management in China. The development goals, major research tasks, and technological approaches are further proposed. To develop a preventative public health emergency response network in China, we suggest that a major national biological monitoring and early-warning project should be established for health emergency response, relevant laws and regulations promulgated and revised, data integration and sustainable development of the emergency management mechanism maintained, an intelligent health emergency response industry encouraged, and professionals for medical care and preventative medicine integrated.

Carbon exchange between forest ecosystems and the atmosphere play an important role in global carbon cycle, which is difficult to be accurately quantified due to the large uncertainties in scaling up site-scale observations or filling-up measurement gaps. A process-oriented model equipped with comprehensive processes to explicitly simulating coupled carbon, nitrogen and water cycling, is hypothesized to reduce the uncertainties in quantification of forest carbon fluxes. To test this hypothesis, the Catchment Nutrient Management Model – DeNitrification-DeComposition (CNMM-DNDC), as a hydro-biogeochemical model that dynamically couples the carbon, nitrogen, phosphorous and water cycling processes, was updated in this study by incorporating a new forest growth module derived from the Biome-BGC model and validating the updates using multiple-year continuous observations of carbon and water fluxes at the site scale. The updated model has improved the processes of photosynthesis, litter decomposition, allocation, respiration and mortality to more effectively capture the transformation and transportation of nutrients in plant-soil-water continuum. The observed gross primary productivity (GPP), ecosystem respiration (ER), net ecosystem carbon dioxide exchange (NEE) and evapotranspiration (ET) of three typical forest sites subject to subtropical and temperate climates in eastern Asia (2003–2010) were used for the model calibration and validation. Compared with the original model in validation, the updated model showed significant improvements in simulating the daily dynamics and inter-annual variations of each variable, with the NRMSE values decreased by 46 % and 54 %, 65 % and 37 %, 4 % and -6 %, and 38 % and -3 % for GPP, ER, NEE, and ET on daily and annual scales, respectively. The comparable performances of both model versions for annual NEE emphasizes the importance of validating each component of carbon fluxes to avoid the offsetting of model errors. The canopy average specific leaf area, fraction of leaf nitrogen in Rubisco, annual leaf and fine root turnover fraction, maximum stomatal conductance and the ratio of carbon to nitrogen in leaves and fine roots were identified as the sensitive eco-physiological parameters affecting the simulations of GPP and ER. In addition, the meteorological variables of solar radiation, humidity and air temperature also showed strong influences on the simulated GPP and ER. The relatively satisfactory performances demonstrated that the modified model has the ability to capture the daily dynamics and inter-annual variations of carbon fluxes for forests in temperate and subtropical zones, which is essential for estimating the emissions of greenhouse gases at the regional or global scales. [ABSTRACT FROM AUTHOR]

Over the past six decades, carbonyl sulfide (COS) in terrestrial ecosystems has been extensively studied, with research focusing on exploring its ecological and environmental effects, estimating source–sink volume, and identifying influencing factors. The global terrestrial COS sink has been estimated to be about 1.194–1.721 Tg a−1, with the terrestrial sink induced by plants and soils 0.50–1.20 Tg a−1, accounting for 41%–69% of the total. Hence, the role of plants and soils as COS sinks has been extensively explored. Now we know that factors such as the activity of carbonic anhydrase (CA), leaf structural traits, soil microbial activity, and environmental factors play significant roles in the COS budget. Developments in observational techniques have also made important contributions to the COS budget. This paper provides an overview of the research progress made on COS based on a comprehensive review of the literature. Then, it highlights the current research hotspots and issues requiring further exploration. For instance, it has been demonstrated that there are still significant uncertainties in the estimation of COS sources and sinks, emphasizing the need for further exploration of COS measuring techniques. This review aims to provide comprehensive guidance for COS research in terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

Forest evapotranspiration (ET) is one of the most important factors influencing the terrestrial hydrological cycle and is prone to being influenced by increasing drought events. This highlights the need to understand the interaction between global forest ET and drought. Consequently, we drew 710 sets of ecosystem-scale ET observations from 69 forest sites around the world and then systematically assessed the ET anomalies during droughts across the dominant forest and climate types. Overall, the response of forest ET to drought is non-monotonic. Under severe and extreme droughts with long durations, ET was reduced in most of forests in the world. We attributed the decreased forest ET to both restricted water supply and restricted water consumption by forests; however, lower magnitude and short-term droughts generally increased forest ET, and in some cases, ET even exceeded precipitation during droughts. We attributed this to the increased surface evaporation and the utilization of deep water by deep root systems. Specifically, we find that the positive anomaly of ET under droughts implied the drought paradox, which acts to accelerate the terrestrial hydrological cycle and further amplify the drought. This study as a global synthetic analysis of case studies on the site scale may have great potential for understanding the importance of the drought-modulated forest water cycle and the possibility of increasing drought stress with the effects of the drought paradox. Key words: climate change, water balance, forest hydrology, drought paradox, evapotranspiration. L'evapotranspiration (ET) de la foret est un des plus importants facteurs qui influencent le cycle hydrologique terrestre tout en etant sujette a l'influence des episodes de secheresse de plus en plus frequents. Cela souligne la necessite de comprendre l'interaction entre l'ET globale de la foret et la secheresse. Par consequent, nous avons extrait 710 ensembles d'observations d'ET a l'echelle de l'ecosysteme dans 69 stations forestieres partout dans le monde et nous avons ensuite systematiquement evalue les anomalies de l'ET lors de secheresses parmi les types dominants de forets et de climats. Globalement, la reaction de l'ET de la foret a la secheresse n'est pas monotone. Lors de secheresses severes et extremes qui persistent longtemps, l'ET a diminue dans la plupart des forets dans le monde. Nous avons attribue la diminution de l'ET de la foret a l'approvisionnement restreint en eau et a la consommation reduite d'eau par les forets; cependant, les secheresses moins severes et de courte duree ont generalement augmente l'ET de la foret et dans certains cas l'ET a meme excede la precipitation durant les periodes de secheresse. Nous avons attribue cela a l'augmentation de l'evaporation superficielle et a l'utilisation de l'eau en profondeur par le systeme de racines profondes. Plus precisement, nous trouvons que l'anomalie positive de l'ET en periodes de secheresse implique le paradoxe de la secheresse qui accelere le cycle hydrologique terrestre et amplifie encore davantage la secheresse. Cette etude, en tant qu'analyse synthetique globale d'etudes de cas a l'echelle de la station peut avoir un potentiel eleve pour comprendre l'importance du cycle de l'eau en foret module par la secheresse et la possibilite que le stress du a la secheresse augmente a cause des effets du paradoxe de la secheresse. [Traduit par la Redaction] Mots-cles: changement climatique, bilan hydrique, hydrologie forestiere, paradoxe de la secheresse, evapotranspiration., Introduction Evapotranspiration (ET), which mainly includes soil evaporation and vegetation transpiration, is a critical component of the water cycle in terrestrial ecosystems (Kool et al. 2014) and links water and [...]

Haff disease is an unexplained rhabdomyolysis that occurs within 24 hours after consumption of certain types of freshwater or saltwater fish (1,2). It was first reported in 1924 in the [...]

Rainfall constitutes the primary input in the nutrient flux within forest ecosystems. The forest canopy modulates this flux by partitioning rainfall and selectively absorbing or adding nutrients. In mixed forests, variation in tree species composition regulates rainwater chemical composition, potentially leading to spatial heterogeneity in nutrient distribution and influencing nutrient cycling processes. This study examined the partitioning of rainfall into throughfall and stemflow, as well as their associated nutrient concentrations and fluxes, in a mixed broadleaf and coniferous forest on Changbai Mountain in Northeast China. We observed a rising trend in nutrient contents from rainfall to throughfall and then stemflow. The nutrient contents of stemflow varied largely with tree species due to the differences in canopy structure and bark morphological characteristics. The nutrient input contributed by throughfall and stemflow was 92.30 kg ha−1 during the observation period, and most elements underwent passive leaching through washout except for F− and Na+. We note that the nutrient fluxes in stemflow differed among tree species, with Pinus koraiensis (PK) delivering more acid group anions and Quercus mongolica (QM) providing more cations. Our research provides new insights into nutrient cycling within mixed forest canopies, sparking a transformative advancement in forest management and protection strategies through hydrochemistry-driven solutions. [ABSTRACT FROM AUTHOR]

Evapotranspiration (ET) is a very important variable in the global water cycle, carbon cycle, and energy cycle. However, there are still some uncertainties in existing ET products. Therefore, this paper evaluates the uncertainty of three widely used global ET products (ERA5-Land, GLDAS-Noah, and MERRA-2) based on the three-cornered hat (TCH) method, and generates a new ET product based on this. The new product is a long-series global monthly ET dataset with a spatial resolution of 0.25° × 0.25° and a time span of 21 years. The results show that ERA5-Land (8.46 mm/month) has the lowest uncertainty among the three ET products, followed by GLDAS-Noah (8.81 mm/month) and MERRA-2 (11.78 mm/month). The new product (TCH) captures ET trends in different regions as well as validating against in situ flux observations, and it exhibits better performance than the re-analysis dataset (ERA5-Land) in vegetation classifications such as evergreen needle-leaf forest, grassland, open shrubland, savanna, and woody savanna. The linear trend analysis of the new product shows a significant decreasing trend in south-eastern South America and southwestern parts of Africa, and an increasing trend in almost all other regions, including eastern North America, north-eastern South America, western Europe, north-central Africa, southern Asia, and south-eastern Oceania. [ABSTRACT FROM AUTHOR]

Snce December 2016, the number of human infections vith avian influenza A(H7N9) virus in China has increased markedly (1,2), prompting concerns of pandemic influenza. Early signals of greater human-to-human transmissibility [...]