通讯机构：
[Liu, Gao-Qiang] H;Hunan Provincial Key Laboratory of Forestry Biotechnology, Central South University of Forestry & Technology, Changsha, China<&wdkj&>International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology of Hunan Province, Central South University of Forestry & Technology, Changsha, China<&wdkj&>Microbial Variety Creation Center, Yuelushan Laboratory of Seed Industry, Changsha, China
摘要：
Ganoderic acids (GAs) are well recognized as important pharmacological components of the medicinal species belonging to the basidiomycete genus Ganoderma. However, transcription factors directly regulating the expression of GA biosynthesis genes remain poorly understood. Here, the genome of Ganoderma lingzhi is de novo sequenced. Using DNA affinity purification sequencing, we identify putative targets of the transcription factor sterol regulatory element-binding protein (SREBP), including the genes of triterpenoid synthesis and lipid metabolism. Interactions between SREBP and the targets are verified by electrophoretic mobility gel shift assay. RNA-seq shows that SREBP targets, mevalonate kinase and 3-hydroxy-3-methylglutaryl coenzyme A synthetase in mevalonate pathway, sterol isomerase and lanosterol 14-demethylase in ergosterol biosynthesis, are significantly upregulated in the SREBP overexpression (OE::SREBP) strain. In addition, 3 targets involved in glycerophospholipid/glycerolipid metabolism are upregulated. Then, the contents of mevalonic acid, lanosterol, ergosterol and 13 different GAs as well as a variety of lipids are significantly increased in this strain. Furthermore, the effects of SREBP overexpression on triterpenoid and lipid metabolisms are recovered when OE::SREBP strain are treated with exogenous fatostatin, a specific inhibitor of SREBP. Taken together, our genome-wide study clarify the role of SREBP in triterpenoid and lipid metabolisms of G. lingzhi. An integration of genomic, DAP-seq, RNA-seq, metabolomic and genetic approaches identifies SREBP as a key transcription factor regulating triterpenoid and lipid metabolisms in the medicinal fungus Ganoderma lingzhi.
通讯机构：
[Xiang, W.] F;Faculty of Life Science and Technology, China
关键词：
Abiotic and biotic factors;Biodiversity;Functional composition;Functional traits;Soil microbial diversity;Stand structure
摘要：
Tree species diversity is assumed to be an important component in managing forest ecosystems because of effects on multiple functions or ecosystem multifunctionality. However, the importance of tree diversity in determining multifunctionality in structurally complex subtropical forests relative to other regulators (e.g., soil microbial diversity, stand structure, and environmental conditions) remains uncertain. In this study, effects of aboveground (species richness and functional and structural diversity) and belowground (bacterial and fungal diversity) biodiversity, functional composition (community-weighted means of species traits), stand structure (diameter at breast height and stand density), and soil factors (pH and bulk density) on multifunctionality (including biomass production, carbon stock, and nutrient cycling) were examined along a tree diversity gradient in subtropical forests. The community-weighted mean of tree maximum height was the best predictor of ecosystem multifunctionality. Functional diversity explained a higher proportion of the variation in multifunctionality than that of species richness and fungal diversity. Stand structure -played an important role in modulating the effects of tree diversity on multifunctionality. The work highlights that species composition and maximizing forest structural complexity are effective strategies to increase forest multifunctionality while also conserving biodiversity in the management of multifunctional forests under global environmental changes.
通讯机构：
[Luan, Guodong; Lu, Xuefeng] Q;Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China<&wdkj&>Shandong Energy Institute, Qingdao, China<&wdkj&>Qingdao New Energy Shandong Laboratory, Qingdao, China<&wdkj&>College of Life Science, University of Chinese Academy of Sciences, Beijing, China<&wdkj&>Dalian National Laboratory for Clean Energy, Dalian, China<&wdkj&>Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China<&wdkj&>Shandong Energy Institute, Qingdao, China<&wdkj&>Qingdao New Energy Shandong Laboratory, Qingdao, China<&wdkj&>College of Life Science, University of Chinese Academy of Sciences, Beijing, China<&wdkj&>Dalian National Laboratory for Clean Energy, Dalian, China<&wdkj&>Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
摘要：
Photosynthesis can be impaired by combined high light and high temperature (HLHT) stress. Obtaining HLHT tolerant photoautotrophs is laborious and time-consuming, and in most cases the underlying molecular mechanisms remain unclear. Here, we increase the mutation rates of cyanobacterium Synechococcus elongatus PCC 7942 by three orders of magnitude through combinatory perturbations of the genetic fidelity machinery and cultivation environment. Utilizing the hypermutation system, we isolate Synechococcus mutants with improved HLHT tolerance and identify genome mutations contributing to the adaptation process. A specific mutation located in the upstream non-coding region of the gene encoding a shikimate kinase results in enhanced expression of this gene. Overexpression of the shikimate kinase encoding gene in both Synechococcus and Synechocystis leads to improved HLHT tolerance. Transcriptome analysis indicates that the mutation remodels the photosynthetic chain and metabolism network in Synechococcus. Thus, mutations identified by the hypermutation system are useful for engineering cyanobacteria with improved HLHT tolerance. Cyanobacteria mutants with improved tolerance to combined high light and high temperature (HLHT) are rarely reported. Here, the authors use a hypermutation system for adaptive laboratory evolution and identify a mutant with improved HLHT tolerance by enhancing expression of shikimate kinase.
摘要：
Water purification from As(III)-contaminated groundwater is difficult but highly needed. Herein, a new polylactic acid ZIF-8 biocomposite nanofiber mat (ZIF-8@PLA/NFM) was fabricated using an electrospinning technique for As(III) decontamination. The active component, ZIF-8 nanoparticles, are uniformly embedded in sustainable PLA fibers and can be rapidly contacted by As(III), achieving fast kinetics and high utilization of nanoparticles. The removal experiments show that the ZIF-8@PLA/NFM can effectively remove As(III), especially in combination with H2O2. The 50%-ZIF-8@PLA/NFM with 1 mM H2O2 reduced 1000 mu g/L As(III) to less than 10 mu g/L in just 5 min through the synergy of oxidation and adsorption. The maximum sorption capacity for As(III) on 50-ZIF-8@PLA/NFM was 11.61 +/- 0.99 mg/g, which increased to 39.25 +/- 3.84 mg/g with the addition of H2O2. It performed well in the pH range of 4-9. The combination of H2O2 broadened its effective pH operating range (3-10) as well as enhanced interference resistance, enabling deep removal of As(III) across a wide range of water environments. The As(III)-spiked natural water (100 mu g/L) could be purified to drinking standard level by ZIF-8@PLA/NFM within 60 min. In combination with H2O2, the removal efficiency was reduced by only 1.5% at the fifth reuse. Macroscopic experiments and microscopic characterization suggest that the adsorption follows the inner-sphere complexes mechanism. The study provides a novel approach for the fabrication of efficient, easy-to-use, and sustainable MOFs-based biocomposite for As(III) decontamination.
摘要：
To investigate the mechanisms by which g-C(3)N(4) alleviates metal(loid)-induced phytotoxicity, rice seedlings were exposed to 100 and 250 mg/kg graphitic carbon nitride (g-C(3)N(4)) with or without coexposure to 10 mg/kg Cd and 50 mg/kg As for 30 days. Treatment with 250 mg/kg g-C(3)N(4) significantly increased shoot and root fresh weight by 22.4-29.9%, reduced Cd and As accumulations in rice tissues by 20.6-26.6%, and elevated the content of essential nutrients (e.g., K, S, Mg, Cu, and Zn) compared to untreated controls. High-throughput sequencing showed that g-C(3)N(4) treatment increased the proportion of plant-growth-promoting endophytic bacteria, including Streptomyces, Saccharimonadales, and Thermosporothrix, by 0.5-3.30-fold; these groups are known to be important to plant nutrient assimilation, as well as metal(loid) resistance and bioremediation. In addition, the population of Deinococcus was decreased by 72.3%; this genus is known to induce biotransformation As(V) to As(III). Metabolomics analyses highlighted differentially expressed metabolites (DEMs) involved in the metabolism of tyrosine metabolism, pyrimidines, and purines, as well as phenylpropanoid biosynthesis related to Cd/As-induced phytotoxicity. In the phenylpropanoid biosynthesis pathway, the increased expression of 4-coumarate (1.13-fold) and sinapyl alcohol (1.26-fold) triggered by g-C(3)N(4) coexposure with Cd or As played a critical role in promoting plant growth and enhancing rice resistance against metal(loid) stresses. Our findings demonstrate the potential of g-C(3)N(4) to enhance plant growth and minimize the Cd/As-induced toxicity in rice and provide a promising nanoenabled strategy for remediating heavy metal(loid)-contaminated soil.
摘要：
With the widespread use of nanoenabled agrochemicals, it is essential to evaluate the food safety of nanomaterials (NMs)-treated vegetable crops in full life cycle studies as well as their potential impacts on human health. Tomato seedlings were foliarly sprayed with 50 mg/L ZnO NMs, including ZnO quantum dots (QDs) and ZnO nanoparticles once per week over 11 weeks. The foliar sprayed ZnO QDs increased fruit dry weight and yield per plant by 39.1% and 24.9, respectively. It also significantly increased the lycopene, amino acids, Zn, B, and Fe in tomato fruits by 40.5%, 15.1%, 44.5%, 76.2%, and 12.8%, respectively. The tomato fruit metabolome of tomatoes showed that ZnO NMs upregulated the biosynthesis of unsaturated fatty acids and sphingolipid metabolism and elevated the levels of linoleic and arachidonic acids. The ZnO NMs-treated tomato fruits were then digested in a human gastrointestinal tract model. The results of essential mineral release suggested that the ZnO QDs treatment increased the bioaccessibility of K, Zn, and Cu by 14.8-35.1% relative to the control. Additionally, both types of ZnO NMs had no negative impact on the α-amylase, pepsin, and trypsin activities. The digested fruit metabolome in the intestinal fluid demonstrated that ZnO NMs did not interfere with the normal process of human digestion. Importantly, ZnO NMs treatments increased the glycerophospholipids, carbohydrates, amino acids, and peptides in the intestinal fluids of tomato fruits. This study suggests that nanoscale Zn can be potentially used to increase the nutritional value of vegetable crops and can be an important tool to sustainably increase food quality and security.
关键词：
Tree rings;Radial growth;Drought resilience;Resistance;Recovery;Broadleaf tree species
摘要：
With the intensification of climate warming, more frequent and hotter droughts are a significant risk to forest ecosystems around the globe, including temperate biomes. To accurately predict the response of forests to drought, it is necessary to provide comprehensive information on the resilience of tree growth, its spatiotemporal changes and drivers. This information is often lacking for broadleaf species in temperate regions. To fulfill this aim, we analyzed 3177 ring-width series from 1981 trees covering 40 sites for four dominant broad-leaf tree species (Fraxinus mandshurica, Phellodendron amurense, Juglans mandshurica, and Quercus mongolica) in temperate forests in northeastern China. We quantified the resilience (resistance and recovery) of tree growth to extreme droughts. Minimum temperatures in most seasons and warm conditions and drought stress in early summer were the main factors limiting growth. Among the four tree species, Q. mongolica had the weakest growth resistance to drought and the fastest growth recovery from drought. Juglans mandshurica had a significantly (p < 0.05) higher drought resilience than F. mandshurica and P. amurense. Tree resilience presented a clear spatial pattern driven by differences in site condition and local climate. The resistance (recovery) to drought decreased (increased) with increasing latitude and longitude, and increased (decreased) with elevation. Q. mongolica exhibited a decrease in resistance and increase in recovery through time, whereas the other three tree species showed the opposite pattern. Fraxinus mandshurica, J. mandshurica, and Q. mongolica had high resistance (recovery) in warmer-wetter (colder-drier) regions. In contrast, P. amurense had reduced recovery in cold sites and low resistance in warm sites. The resistance and recovery indices of these sympatric tree species confirmed that different tree species have distinct strategies to cope with drought that is influenced by tree condition and local environment. The influence of biogeographical factors is often more important than other factors and should be considered when studying forest resilience to drought.
作者机构：
[Cao, Yixuan; Wang, Jun; Yan, Wende; Lei, Junjie; Shao, Qiwen; Chen, Yazhen; Xu, Yichen; Dan, Qing] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha 410004, Peoples R China.;[Dang, Peng; Cao, Yixuan; Wang, Jun; Dang, P; Yan, Wende; Lei, Junjie; Shao, Qiwen; Chen, Yazhen; Xu, Yichen; Dan, Qing] Natl Engn Lab Appl Technol Forestry & Ecol South C, Changsha 410004, Peoples R China.;[Peng, Yuanying] St Xavier Univ, Coll Arts & Sci, Chicago, IL 60655 USA.;[Chen, Xiaoyong] Governors State Univ, Coll Arts & Sci, University Pk, IL 60484 USA.;[Dang, Peng; Dang, P] Cent South Univ Forestry & Technol, Coll Forestry, Changsha 410004, Peoples R China.
通讯机构：
[Dang, P ; Yan, WD ] C;[Dang, P] N;Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha 410004, Peoples R China.;Natl Engn Lab Appl Technol Forestry & Ecol South C, Changsha 410004, Peoples R China.;Cent South Univ Forestry & Technol, Coll Forestry, Changsha 410004, Peoples R China.
关键词：
Chinese fir plantation;ecological stoichiometry;soil enzymes;soil microorganisms;soil nutrients
摘要：
Forests undergo a long-term development process from young to mature stages, yet the variations in soil nutrients, enzyme activities, microbial diversity, and community composition related to forest ages are still unclear. In this study, the characteristics of soil bacterial and fungal communities with their corresponding soil environmental factors in the young, middle, and mature stages (7, 15, and 25-year-old) of Chinese fir plantations (CFP) in the subtropical region of China were investigated in 2021. Results showed that the alpha diversity indices (Chao1 and Shannon) of soil bacteria and fungi were higher in 15 and 25-year-old stands than in 7-year-old stand of CFP, while the soil pH, soil water content, soil organic carbon, total nitrogen, total phosphorus, sucrase, urease, acid phosphatase, catalase, and microbial biomass carbon, nitrogen, and phosphorus showed higher in 7-year-old stand than other two stands of CFP. The nonmetric multidimensional scaling analysis revealed that the soil microbial species composition was significantly different in three stand ages of CFP. The redundancy and canonical correspondence analysis indicated that the soil urease and microbial biomass nitrogen were the main factors affecting soil bacterial and fungal species composition. Our findings suggested that soil microbial diversity and community structure were inconsistent with changes in soil nutrients and enzyme activities during CFP development, and enhancing stand nurturing and soil nutrient accumulation in the mid-development stage were beneficial to the sustainable management of CFP.
作者机构：
[Lei, Junjie; Chen, Yazhen; Zheng, Wei; Xu, Yichen; Yan, Wende; Jiang, Xingjian] Cent South Univ Forestry & Technol, Fac Life Sci & Technol, Changsha 410004, Peoples R China.;[Lei, Junjie; Chen, Yazhen; Zheng, Wei; Xu, Yichen; Yan, Wende; Jiang, Xingjian] Natl Engn Lab Appl Technol Forestry & Ecol South C, Changsha 410004, Peoples R China.;[Lei, Junjie; Chen, Yazhen; Zheng, Wei; Xu, Yichen; Yan, Wende; Jiang, Xingjian] Natl Observat Res Stn Forest Ecosyst Lutou Forest, Yueyang 414000, Hunan, Peoples R China.;[Dang, Peng] Cent South Univ Forestry & Technol, Coll Forestry, Changsha 410004, Peoples R China.;[Yan, Wende] Key Lab Urban Forest Ecol Hunan Prov, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Wende Yan] F;Faculty of Life Science and Technology, Central South University of Forestry & Technology, Changsha 410004, China<&wdkj&>National Engineering Laboratory for Applied Technology of Forestry & Ecology in South China, Changsha 410004, China<&wdkj&>National Observation research Station of Forest Ecosystem of Lutou Forest Farm in Hunan Province, Yueyang 414000, Hunan, China<&wdkj&>Key Laboratory of Urban Forest Ecology of Hunan Province, Changsha 410004, Hunan, China<&wdkj&>Key Laboratory of Subtropical Forest Ecology of Hunan Province, Changsha 410004, Hunan, China
关键词：
Community assembly;Elevation;Fallen wood;Partial least squares path model;Soil fungal diversity
摘要：
Ecological stoichiometry is crucial in understanding nutrient dynamics and its impact on plant growth and development at various ecological scales. Among the different nutrients, nitrogen (N) and phosphorus (P) have been widely recognized as key elements regulating substance transport, energy utilization, and ecosystem conversion. The N:P ratio in plants serves as a sensitive indicator of ecological processes, reflecting the availability and balance of these nutrients. Therefore, studying the ecological stoichiometry of N and P is essential for accurately assessing soil fertility and site productivity, particularly in forest ecosystems with low-fertility soils. In this study conducted in Huitong, Hunan province, southern China, the contents of N and P, as well as the N:P ratios, were investigated in plant-soil systems across four different aged stands of Chinese fir forests (3-, 8-, 18-, and 26-year-old stands). The results revealed varying concentrations of N and P in soils and foliage across the different plantations. Soil N concentrations increased by approximately 4%, 30%, and 22% in 8-, 18-, and 26-year-old plantations compared to the 3-year-old plantation. Soil P concentration was significantly higher in 8-, 18-, and 26-year-old plantations compared to the 3-year-old plantation. The average soil N:P ratio followed the order of 3-year-old plantation > 18-year-old plantation > 26-year-old plantation > 8-year-old plantation. Regarding foliage, both N and P contents exhibited a similar pattern across the different aged leaves, with current-year-old leaves having higher concentrations than 1-year-old, 2-year-old, and 3-year-old leaves in all four Chinese fir plantations. The study further established relationships between soil and foliage nutrient ratios. Soil N:P ratio was positively correlated with soil N content but negatively associated with soil P content. The foliage N:P ratio also showed a significant negative correlation between leaf N and foliage P content. These findings suggest that soil nutrient conditions improved with the aging of Chinese fir plantations, mainly due to increased inputs of above- and below-ground litter. Overall, this study provides valuable insights into the ecological stoichiometry of N and P in Chinese fir plantations, offering a scientific basis for sustainable forest management practices in southern China.
摘要：
Agroforest systems have been widely recognized as an integrated approach to sustainable land use for addressing the climate change problem because of their greater potential to sequester atmospheric CO2 with multiple economic and ecological benefits. However, the nature and extent of the effects of an age-sequence of agroforestry systems on carbon (C) storage remain largely unknown. To reveal the influence of different aged poplar-crop systems on C stocks, we investigated the variation in biomass and C storage under four aged poplar-crop agroforest systems (3-, 9-, 13-, and 17-year-old) in the Henan province of China. The results showed that stand biomass increased with forest age, ranging from 26.9 to 121.6 t/ha in the corresponding four aged poplar-crop systems. The poplar tree biomass accounted for >80% of the total stand biomass in these poplar-crop agroforestry systems, except in the 3-year-old agroforestry system. The average stand productivity peaked in a 9-year-old poplar-crop system (11.8 t/ha/yr), the next was in 13- and 17-year-old agroforestry systems, and the minimum was found in 3-year-old poplar-crop stands (4.8 t/ha/yr). The total C stocks increased, with aging poplar-crop systems ranging from 99.7 to 189.2 t/ha in the studied agroforestry systems. The proportion of C stocks accounted for about 6, 25, and 69% of the total C stocks in the crop, poplar tree, and soil components in all studied agroforestry ecosystems, respectively. Our results suggested that the poplar-crop system, especially in productive and mature stages, is quite an effective agroforestry model to increase the study site’s biomass production and C stocks. This study highlighted the importance of agroforestry systems in C storage. It recommended the poplar-crop agroforest ecosystems as a viable option for sustainable production and C mitigation in the central region of China.
摘要：
The forest ecosystem is the largest carbon reservoir in the terrestrial ecosystem, with soil organic carbon (SOC) being its most important component. How does the distribution of forest SOC distribution change under the influence of regional location, forest succession, human activities, and soil depth? It is the basis for understanding and evaluating the value of forest SOC reservoirs and improving the function of forest soil carbon sinks. In this paper, soil organic carbon concentrations (SOCCs) and environmental factors were measured by setting 14 experimental plots and 42 soil sampling sites in different forest communities and different elevations in the Maoershan Mountains. The redundancy analysis (RDA) method was used to study the relationship between SOC distribution and external factors. The results show that SOC distribution was sensitive to elevation, forest community, and soil layer. It had obvious surface aggregation characteristics and increased significantly with the increase in elevation. Among them, SOCCs increase by 1.80 g/kg with every 100 m increase in elevation, and that decreased by 5.43 g/kg with every 10 cm increase in soil depth. The SOC distribution in natural forests is greater than that in plantations, and the spatial variation in SOC distribution in plantations is higher due to the effect of cutting and utilization. SOC distribution is the result of many environmental factors. The response of SOC distribution to the forest community indicates that the development of plantations into natural forests will increase SOC, and excessive interference with forests will aggravate SOC emissions. Therefore, strengthening the protection of natural forests, restoring secondary forests, and implementing scientific and reasonable plantation management are important measures for improving the SOC reservoir’s function.
期刊：
Ecotoxicology and Environmental Safety,2023年249:114458 ISSN：0147-6513
通讯作者：
Chen, L.;Pan, Y.
作者机构：
[Chen, Zekai; Zheng, Wei; Pan, Yuliang; Yan, Wende; Tang, Jun; Hu, Lei] Cent South Univ Forestry & Technol, Fac Life Sci & Technol, Changsha 410004, Peoples R China.;[Chen, Zekai; Zheng, Wei; Pan, Yuliang; Yan, Wende; Tang, Jun; Hu, Lei] Natl Engn Lab Appl Technol Forestry & Ecol South C, Changsha 410004, Peoples R China.;[Chen, Zekai; Zheng, Wei; Pan, Yuliang; Yan, Wende; Tang, Jun; Hu, Lei] Lab Urban Forest Ecol Hunan Prov, Changsha 410004, Hunan, Peoples R China.;[Chen, Lijun] Cent South Univ Forestry & Technol, Fac Forestry, Changsha 410004, Peoples R China.;[Chen, Xiaoyong] Governors State Univ, Coll Arts & Sci, University Pk, IL 60484 USA.
通讯机构：
[Pan, Y.; Chen, L.] F;Faculty of Life Science and Technology, Central South University of Forestry & Technology, Changsha 410004, China<&wdkj&>National Engineering Laboratory for Applied Technology of Forestry & Ecology in South China, Changsha 410004, China<&wdkj&>Laboratory of Urban Forest Ecology of Hunan Province, Changsha, Hunan 410004, China
关键词：
Perfluorinated compounds;Bacterial and fungal communities;PFOA;PFOS
期刊：
Carbon Balance and Management,2023年18(1):1-14 ISSN：1750-0680
通讯作者：
Liu, SG
作者机构：
[Liu, Shuguang; Chen, Wei; Zhu, Yu; Yan, Wende; Wang, Zhao; Feng, Shuailong] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha 410004, Peoples R China.;[Liu, Shuguang; Chen, Wei; Zhu, Yu; Yan, Wende; Wang, Zhao; Feng, Shuailong] Cent South Univ Forestry & Technol, Natl Engn Lab Appl Technol Forestry & Ecol South C, Changsha 410004, Peoples R China.;[Zhao, Shuqing] Peking Univ, Coll Urban & Environm Sci, Key Lab Earth Surface Proc, Minist Educ, Beijing 100871, Peoples R China.;[Wu, Yiping] Xi An Jiao Tong Univ, Dept Earth & Environm Sci, Xian 710049, Shaanxi, Peoples R China.;[Xiao, Jingfeng] Univ New Hampshire, Inst Study Earth Oceans & Space, Earth Syst Res Ctr, Durham, NH 03824 USA.
通讯机构：
[Liu, SG ] C;Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha 410004, Peoples R China.;Cent South Univ Forestry & Technol, Natl Engn Lab Appl Technol Forestry & Ecol South C, Changsha 410004, Peoples R China.
关键词：
Ecosystem level;Water use efficiency;FLUXNET;Changing trend;Driving factors
摘要：
Understanding temporal trends and varying responses of water use efficiency (WUE) to environmental changes of diverse ecosystems is key to predicting vegetation growth. WUE dynamics of major ecosystem types (e.g., forest, grassland and cropland) have been studied using various WUE definitions/metrics, but a comparative study on WUE dynamics and their driving forces among different ecosystem types using multiple WUE metrics is lacking. We used eddy covariance measurements for 42 FLUXNET2015 sites (396 site years) from 1997 to 2014, as well as three commonly used WUE metrics (i.e., ecosystem, inherent, and underlying WUE) to investigate the commonalities and differences in WUE trends and driving factors among deciduous broadleaf forests (DBFs), evergreen needleleaf forests (ENFs), grasslands, and croplands. Our results showed that the temporal trends of WUE were not statistically significant at 73.8% of the forest, grassland and cropland sites, and none of the three WUE metrics exhibited better performance than the others in quantifying WUE. Meanwhile, the trends observed for the three WUE metrics were not significantly different among forest, grassland and cropland ecosystems. In addition, WUE was mainly driven by atmospheric carbon dioxide concentration at sites with significant WUE trends, and by vapor pressure deficit (VPD) at sites without significant trends (except cropland). Our findings revealed the commonalities and differences in the application of three WUE metrics in disparate ecosystems, and further highlighted the important effect of VPD on WUE change.
作者机构：
[Mengxiao Yu; Xin Xiong; Xiangping Tan; Qi Deng; Junhua Yan] Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China;University of Chinese Academy of Sciences, Beijing, China;[Ying-Ping Wang] CSIRO Oceans and Atmosphere, PMB 1, Aspendale, Australia;[Xi Fang; Jinlei Chen] Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, China;[Shuo Zhang; Nannan Cao; Pingping Xu] Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China<&wdkj&>University of Chinese Academy of Sciences, Beijing, China
通讯机构：
[Qi Deng; Junhua Yan] K;Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China<&wdkj&>Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
摘要：
Changes in litter quality (carbon:nitrogen, C:N) and above-ground biomass (AGB) following vegetation restoration significantly impact soil physicochemical properties, yet their effects on soil microbial metabolic limitations remain unclear. We measured litter quality, AGB, soil physicochemical properties, and extracellular enzyme activity (EEA) along a vegetation restoration gradient (7, 14, 49, 70 years, and nearly climax evergreen broadleaved forests) in southern China. We also evaluated soil microbial metabolic limitations by a vector analysis of the EEA. Results revealed the soil microbial metabolisms were co-limited by C and phosphorus (P). The microbial C limitation initially decreased (before 14 years) and then increased, while the microbial P limitation initially increased (before 49 years) and then decreased. Partial least squares path modeling (PLS-PM) showed that the microbial C limitation was mainly attributed to microbial C use efficiency induced by litter quality, suggesting that microorganisms may transfer cellular energy between microbial growth and C-acquiring enzyme production. The microbial P limitation was primarily correlated with AGB-driven change in soil elements and their stoichiometry, highlighting the importance of nutrient stoichiometry and balance in microbial metabolism. The shifts between microbial C and P limitations and the strong connections of plant-soil-microbe processes during vegetation restoration revealed here will provide us with helpful information for optimal management to achieve forest restoration success.
