通讯机构：
[Liu, SG ] C;Cent South Univ Forestry & Technol, Changsha 410004, Peoples R China.
关键词：
Chinese fir plantations;Ecological network;Ecological stoichiometry;Enzyme stoichiometry;Forest restoration;Nutrient limitation;Soil biota
摘要：
Forest ecosystem productivity and function is strongly influenced by the interaction between soil organisms and their resource use that can be impeded by an imbalance of ecological stoichiometry. Soil microorganisms are known to have an important role in biogeochemical cycling which is strongly influenced by ecological stoichiometry. However, there is limited understanding of how soil micro-food web respond to stoichiometric imbalances during forest restoration. Here, we investigated the effect of forest restoration on soil physio-chemical properties and the structure and function of soil micro-food web along a chronosequence of transformation stages: (i) early stage monoculture plantation of Chinese fir (Cunninghamia lanceolata) comprised of three age classes (5, 10 and 20years); (ii) mid-stage conifer-broadleaved mixed forest; and (iii) late-stage mixed species broadleaved forest in south China. Results showed that forest restoration from C. lanceolata monocultures to mixed species broadleaved forest significantly increased soil organic carbon and total nitrogen. Soil bacteria, fungi, protists and nematodes abundance increased and the co-occurrence networks of soil biota became more complex and stable along the restoration chronosequence. In contrast, soil nitrogen and phosphorus limitations, particularly phosphorus limitation, increased along the chronosequence. In addition, soil exoenzyme activity suggested that the microbial investment in resource acquisition shifted from C- to nutrient-acquiring enzymes from the earlier to the later restoration stages. Availability of soil resources (e.g., dissolved organic carbon, ammonium, and available phosphate) appeared to have an important role in regulating soil food web composition, structure and stability during forest restoration. We conclude that nutrient limitation, particularly phosphorus limitation, likely has an important role in determining the stability of soil food webs during forest restoration. These findings contribute to our understanding of the relationships between soil nutrient limitation and soil micro-food web, and have implications for carbon sequestration through forest restoration and management in southern China.
摘要：
Enzymatic degradation of plastic is an effective means of plastic recycling and pollution control. However, the strong chemical inertness of polypropylene plastic (PP) severely impedes its oxidative cleavage, making it resistant to degradation. In this study, based on sequence screening of Hidden Markov Model (HMM), a dioxygenase (HIS1) was identified and characterized to be effective in PP oxidation. Various kinds of PP products, including plastic films, microplastics, and disposable water cups or bags, were HIS1-degraded with cracks and holes on the surface. The hydrophobic binding was the primary force driving oxidative degradation in the specific cavity of HIS1. The discovery of HIS1 achieved a zero breakthrough in PP biodegradation, providing a promising candidate for the selection and evolution of degrading enzymes.
摘要：
Metal(loid) contamination of agricultural soils has become an alarming issue due to its detrimental impacts on soil health and global agricultural production. Therefore, environmentally sustainable and cost-effective solutions are urgently required for soil remediation. Biochar, particularly nano-biochar, exhibits superior and high-performance capabilities in the remediation of metal(loid)-contaminated soil, owing to its unique structure and large surface area. Current researches on nano-biochar mainly focus on safety design and property improvement, with limited information available regarding the impact of nano-biochar on soil ecosystems and crop defense mechanisms in metal(loid)-contaminated soils. In this review, we systematically summarized recent progress in the application of nano-biochar for remediation of metal(loid)-contaminated soil, with a focus on possible factors influencing metal(loid) uptake and translocation in soil-crop systems. Additionally, we conducted the potential/related mechanisms by which nano-biochar can mitigate the toxic impacts of metal(loid) on crop production and security. Furthermore, the application of nano-biochar in field trials and existing challenges were also outlined. Future studies should integrate agricultural sustainability and ecosystem health targets into biochar design/selection. This review highlighted the potential of nano-biochar as a promising soil amendment for enhancing the remediation of metal(loid)-contaminated agricultural soils, thereby promoting the synthesis and development of highly efficient nano-biochar towards achieving environmental sustainability.
摘要：
Nitrogen (N) is an essential nutrient for ecosystem productivity, restoration and succession processes. Biological N fixation and chemical N addition are both important strategies for accessing N nutrients in soil ecosystem. However, it is unclear which N supplement strategies is more effective in restoring ecosystem stability, partic-ularly in soil micro-food web component, which plays a crucial role in nutrient cycling. Here, an in-situ study was conducted in a natural grassland to investigate the effects of N supply on soil microbial and nematode com-munities by three legume species: Amorpha fruticose (AF), Derris fordii (DF), and Indigofera atropurpurea (IA) at two interplanting densities (1: low density, 1.5 x 2 m; and 2: high density, 1 x 1 m), and by two N fertilization rates (N5: 5 g N m- 2 y-1 and N10: 10 g N m- 2 y-1). Results showed the microbial biomass of total-PLFA, bacteria, fungi, actinomycetes and chlorophyta increased by DF1 and IA2, and the biomasses of total nema-todes, herbivores and omnivores were promoted by AF1, AF2 and DF1, but the biomass of most components was inhibited by N fertilizers. The interactions of soil micro-food web were complicated by DF1 and DF2, but simplified by N5 and N10. Furthermore, different N supplement strategies showed distinct energy flow patterns, such as the bacterial channel was promoted exclusively in AF2, the plant channel was enhanced in AF1 and AF2, and the fungal channel was boosted in DF1 and DF2 but declined in N5 and N10. These results demonstrated that the structure and energy flow of the soil micro-food web might be benefited by legume interplanting but impaired by N fertilizers. In particular, interplanting with D. fordii granted a more sustainable way of N sup-plementation for promoting the complexity and stability of the soil micro-food web, compared to interplanting with other legume species. Our findings provide better understanding of the interactions between legumes and soil biota and have important implications for sustainable restoration of degraded karst grasslands.
作者机构：
[Liu, Shuguang; Lei, Junjie; Wu, Qinxiang; Li, Zhiqiang; Yan, Wende; Liu, Xin; Wang, Jun; Mao, Can] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha 410004, Peoples R China.;[Liu, Shuguang; Li, Zhiqiang; Yan, Wende; Wang, Jun] Natl Engn Lab Appl Forest Ecol Technol Southern Ch, Changsha 410004, Peoples R China.;[Peng, Yuanying] Lewis Univ, Coll Arts & Sci, Romeoville, IL 60446 USA.;[Chen, Xiaoyong] Governors State Univ, Coll Arts & Sci, University Pk, IL 60484 USA.
通讯机构：
[Chen, XY ] G;[Yan, WD ] C;Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha 410004, Peoples R China.;Natl Engn Lab Appl Forest Ecol Technol Southern Ch, Changsha 410004, Peoples R China.;Governors State Univ, Coll Arts & Sci, University Pk, IL 60484 USA.
关键词：
photosynthetic rate;dynamic process;forest canopy;camphor tree
摘要：
The increase in the global atmospheric CO2 concentration is expected to increase the productivity of forests, but the dynamic processes of such increased productivity in the forest canopy remain unclear. In this study, diurnal and seasonal variations and vertical changes in photosynthetic rates were investigated in Camphor tree (Cinnamomum camphora) forests in subtropical China. The effect of photosynthetically active radiation (PAR) and CO2 concentrations on photosynthetic rates were also examined in the studied forests. Results showed the diurnal patterns of photosynthesis exhibited two peaks on sunny days, but only one peak on cloudy days. The daily average photosynthetic rate on cloudy days was approximately 74% of that on sunny days. The photosynthetic rate decreased along the vertical forest canopy profile. If the photosynthetic rate in the upper canopy layer was 100%, the corresponding rates were 83% and 25% in the middle and lower canopy layers, respectively. The rates of dark respiration derived from the PAR response curve were 1.73, 1.25, and 1.0 mu mol m(-2) s(-1) for the upper, middle, and lower canopy layers, respectively. The apparent quantum yield of photosynthesis was 0.0183, 0.0186, and 0.0327 mu mol CO2 mu mol(-1) PAR for the upper, middle, and lower canopy, respectively. The initial slope of the photosynthetic response curve to CO2 was highest in the upper canopy and lowest in the lower canopy. The seasonal variation in photosynthetic rates exhibited a two-peaked pattern at all canopy positions, with the two peaks occurring in June and September. The stand biomass and biomass carbon storage were 144.7 t ha(-1) and 71.6 t C ha(-1) in the examined forests, respectively. The study provides a scientific reference for future research on accessing carbon sequestration and designing forest management practices, specifically in regulating canopy structure in subtropical regions.
关键词：
Bottom-up control;Carbon flow;Enzymatic activities;Legume intercropping;Nitrogen fertilization;Soil nematode food web
摘要：
Excessive nitrogen (N) loading poses a substantial risk to soil biodiversity and disrupts carbon (C) flows within the soil food web. Intercropping with legumes is often considered a sustainable way to maintain soil N availability and mitigate the associated detrimental effects. However, it remains unclear whether and how legume crops restore energetic attenuation caused by N loading within the soil food web. Here, we conducted a two-year field experiment using randomized block design in a subtropic Camellia oleifera plantation with high wet N deposition. We examined the effects of applying N fertilizers at normal or half levels (168 or 84kgN ha(-1)yr(-1)) and intercropping legumes (Arachis hypogaea or Cassia tora) on the soil nematode food web. We observed that N fertilization suppressed the majority of nematode trophic groups, weakened the stability of food web structure, and diminished the C flows across the bacterial and fungal energy channels. Conversely, intercropping with legumes (particularly with C. tora) bolstered the densities of bacterivore and fungivore nematodes. This enhancement facilitated interactions within the soil micro-food web, and subsequently augmented the C flows within their respective channels. Model predictions suggested that the detrimental effects of N fertilizers on the nematode food web are primarily linked to decreased soil pH resulting from soil N accumulation. Notably, higher soil organic C was found to mitigate these effects. Furthermore, N-enriched legume substrates played a beneficial role in stimulating soil microbial activities and facilitating C flows through bottom-up control. Our findings emphasize the positive impacts of legume crops on mitigating soil biodiversity loss and restoring energetic attenuation within soil food web under N-saturated soil conditions. These findings provide valuable insights for agroforestry management practices aimed at sustaining soil health and ecosystem resilience.
期刊：
Science of The Total Environment,2024年927:172171 ISSN：0048-9697
通讯作者：
Wu, Qian;Yan, Wende
作者机构：
[Zhou, Ping; Guo, Xiaobin; Zheng, Wei; Wu, Jinshui] Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, PR China;[Zheng, Wei] University of Chinese Academy of Sciences, Beijing 100049, PR China;[Zheng, Wei] Faculty of Life Science and Technology, Central South University of Forestry & Technology, Changsha 410004, PR China;[Zheng, Wei] National Engineering Laboratory for Applied Technology of Forestry & Ecology in South China, Changsha 410004, PR China;[Wu, Qian] Faculty of Resources and Environmental Engineering, Anshun University, Anshun 561000, China. Electronic address: csfuwq@163.com
通讯机构：
[Wu, Qian] F;[Yan, Wende] N;Faculty of Resources and Environmental Engineering, Anshun University, Anshun 561000, China. Electronic address:;National Engineering Laboratory for Applied Technology of Forestry & Ecology in South China, Changsha 410004, PR China. Electronic address:
摘要：
Rocky desertification is one of the most ecological problems in the karst context. Although extensive research has been conducted to explore how to restore and protect, the responses of soil fungi and archaea to rocky desertification succession remain limited. Here, four grades of rocky desertification in a karst ecosystem were selected, amplicon sequencing analysis was conducted to investigate fungal and archaeal community adaptation in response to rocky desertification succession. Our findings revealed that the diversity and community structure of fungi and archaea in soils declined with the aggravation of rocky desertification. As the rocky desertification succession intensified, microbial interactions shifted from cooperation to competition. Microbial survival strategies were K-strategist and r-strategist dominated in the early and late stages of succession, respectively. Additionally, the driving factors affecting microorganisms have shifted from vegetation diversity to soil properties as the intensification of rocky desertification. Collectively, our study highlighted that plant diversity and soil properties play important roles on soil microbiomes in fragile karst ecosystems and that environmental factors induced by human activities might still be the dominant factor exacerbating rocky desertification, which could significantly enrich our understanding of microbial ecology within karst ecosystems.
作者机构：
[Wende Yan] National Engineering Laboratory for Applied Technology of Forestry & Ecology in South China, Central South University of Forestry and Technology, Changsha 410004, China;These authors contributed equally to this work.;[Yating Wu] Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China;Author to whom correspondence should be addressed.;[Shuai Ouyang; Liang Chen] Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystem in Hunan Province, Huitong, Huaihua 438107, China
通讯机构：
[Pifeng Lei] F;Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Author to whom correspondence should be addressed.
摘要：
Litter of different species coexists in the natural ecosystem and may induce non-additive effects during decomposition. Identifying and quantifying the origins of species in litter mixtures is essential for evaluating the responses of each component species when mixed with co-occurring species and then unraveling the underlying mechanism of the mixing effects of litter decomposition. Here, we used near-infrared spectroscopy (NIRS) to predict the species composition and proportions of four-tree species foliage mixtures in association with litter crude ash and litter decomposition time. To simulate the whole mixed litter decomposition process in situ, a controlled mixture of four tree species litter leaves consisting of 15 tree species combinations and 193 artificial mixed-species samples were created for model development and verification using undecomposed pure tree species and decomposed litter of single tree species over one year. Two series of NIRS models were developed with the original mass and ash-free weight as reference values. The results showed that these NIRS models could provide an accurate prediction for the percentage of the component species from in the litter leaf mixture’s composition. The predictive ability of the near-infrared spectroscopy model declined marginally with the prolonged litter decomposition time. Furthermore, the model with ash-free litter mass as a reference exhibited a higher coefficient of determination (R2) and a lower standard error of prediction (RMSECV). Thus, our results demonstrate that NIRS presents great potential for not only predicting the organic composition and proportion in multi-species mixed samples in static conditions, but also for samples in dynamic conditions (i.e., during the litter decomposition process), which could facilitate evaluation of the species-specific responses and impacts on the interspecific interactions of co-occurring species in high-biodiversity communities.
作者机构：
[Lei, Junjie; Yan, Wende; Zhang, Yi; He, Ping] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha 410004, Peoples R China.;[He, Ping] Forestry Bur Hunan Prov, Changsha 410004, Peoples R China.;[Yan, Wende] Natl Engn Lab Appl Forest Ecol Technol Southern Ch, Changsha 410004, Peoples R China.;[Peng, Yuanying] Lewis Univ, Coll Arts & Sci, Romeoville, IL 60446 USA.;[Zheng, Wei] Guangxi Forestry Res Inst, Nanning 530002, Peoples R China.
通讯机构：
[Chen, XY ] G;[Yan, WD ] C;Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha 410004, Peoples R China.;Natl Engn Lab Appl Forest Ecol Technol Southern Ch, Changsha 410004, Peoples R China.;Governors State Univ, Coll Arts & Sci, University Pk, IL 60484 USA.
关键词：
camphor forest;root respiration;microbial respiration;carbon cycling;soil CO2 efflux
摘要：
On a global scale, soil respiration (R-s), representing the CO2 flux between the soil surface and the atmosphere, ranks as the second-largest terrestrial carbon (C) flux. Understanding the dynamics between R-s and its autotrophic (R-a) and heterotrophic (R-h) components is necessary for accurately evaluating and predicting global C balance and net ecosystem production under environmental change. In this study, we conducted a two-year root exclusion experiment in subtropical China's Camphor (Cinnamomum camphora (L.) Presl.) forests to assess seasonal changes in R-a and R-h and their relative contributions to R-s. Additionally, we examined the influence of environmental factors on the dynamics of R-a, R-h, and R-s. Our results showed that seasonal mean R-s values were 2.88 mu mol m(-2) s(-1), with mean R-a and R-h of 1.21 and 1.67 mu mol m(-2) s(-1), respectively, in the studied forests. On an annual basis, the annual values of mean R-s in the studied forests were 405 +/- 219 g C m(-2) year(-1), with R-h and R-a accounting for 240 +/- 120 and 164 +/- 102 g C m(-2) year(-1), respectively. The seasonal mean ratio of R-h to R-s (R-h/R-s) was 58%, varying from 45 to 81%. Seasonal changes in R-s and R-h were strongly correlated with soil temperature but not soil water content. Both R-h and R-s increased exponentially with the average soil temperature measured in the topsoil layer (about 5 cm), with Q(10) values of 2.02 and 1.73 for R-h and R-s, respectively. Our results suggest that the composition and activity of soil microbes and fauna play a primary role in releasing carbon flux from soil to the atmosphere in the studied forest ecosystems.
摘要：
Microplastic threats to biodiversity, health and ecological safety are adding to concern worldwide, but the real impacts on the functioning of organisms and ecosystems are obscure owing to their inert characteristics. Here we investigated the long-lasting ecological effects of six prevalent microplastic types: polyethylene (PE), polypropylene (PP), polyamide (PA), polystyrene (PS), polyethylene terephthalate (PET), and polyvinyl chloride (PVC) on soil bacteria at a 2 % (w/w) level. Due to the inertia and lack of available nitrogen of these microplastics, their effects on bacteriome tended to converge after one year and were strongly different from their short-term effects. The soil volumes around microplastics were very specific, in which the microplastic-adapted bacteria (e.g., some genera in Actinobacteria) were enriched but the phyla Bacteroidetes and Gemmatimonadetes declined, resulting in higher microbial nitrogen requirements and reduced organic carbon mineralization. The reshaped bacteriome was specialized in the genetic potential of xenobiotic and lipid metabolism as well as related oxidation, esterification, and hydrolysis processes, but excessive oxidative damage resulted in severe weakness in community genetic information processing. According to model predictions, microplastic effects are indirectly derived from nutrients and oxidative stress, and the effects on bacterial functions are stronger than on structure, posing a heavy risk to soil ecosystems.
作者机构：
[Lei, Junjie; Wang, Guangjun; Wu, Yaohui; Pan, Yuliang; Yan, Wende; Zou, Dongjun; Wang, Jun] College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China;[Peng, Yuanying] College of Arts and Sciences, Saint Xavier University, Chicago, IL, 60655, USA;[Wang, Guangjun; Pan, Yuliang; Wang, Jun] National Engineering Laboratory for Applied Technology of Forestry and Ecology in South China, Changsha, Hunan, 410004, China;[Yan, Wende] National Engineering Laboratory for Applied Technology of Forestry and Ecology in South China, Changsha, Hunan, 410004, China. Electronic address: csfuywd@hotmail.com;[Chen, Xiaoyong] College of Arts and Sciences, Governors State University, University Park, IL 60484, USA. Electronic address: xchen@govst.edu
通讯机构：
[Wende Yan; Xiaoyong Chen] C;College of Arts and Sciences, Governors State University, University Park, IL 60484, USA<&wdkj&>College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China<&wdkj&>National Engineering Laboratory for Applied Technology of Forestry and Ecology in South China, Changsha, Hunan, 410004, China
摘要：
Chromium (Cr) is one of the common environmental pollutants, which causes severe health hazards on human health and environmental security. In this study, we characterized two biochars, a raw biochar (RBC) and a Fe-modified biochar (MBC) made from poplar wood chips and determined the effect of the two biochars on remediation of hexavalent chromium (Cr(VI)) in hydroponic system by monitoring Pak choi growth. Results showed the surface area, pore number and pore volume were significantly higher in MBC than in PBC, but the pore size was larger in PBC than in MBC. When compared to the control, low concentrations of Cr(VI) (≤2mgL(-1)) promoted the growth and biomass production of Pak choi by 10-78%. In contrast, the high concentrations of Cr(VI) (≥4mgL(-1)) showed a significantly reduction of the growth and biomass production of Pak choi by 10-28%. Fe-modified biochar (MBC) had a more significant impact than RBC on the remediation of Cr in the Cr(VI) pollution and improved growth and biomass production of Pak choi to a greater extent. Our study indicated that MBC has a better effect on degrading Cr(VI) pollution. The findings provide scientific basis and reference for the remediation of heavy metals in aquatic ecosystems by using biochar.
期刊：
European Journal of Forest Research,2023年142(4):823-835 ISSN：1612-4669
通讯作者：
Yan, W.;Chen, X.
作者机构：
[Lei, Junjie; Li, Rujie; Yan, Wende] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Natl Engn Lab Appl Forest Ecol Technol Southern Ch, 498 South Shaoshan Rd, Changsha 410004, Hunan, Peoples R China.;[Peng, Yuanying] Lewis Univ, Coll Arts & Sci, Romeoville, IL 60446 USA.;[Cao, Juan] Chinese Acad Agr Sci, Inst Agr Resources & Reg Planning, Beijing 100081, Peoples R China.;[Zhou, Ting; Shi, Xiao; Jia, Qiang] China Int Engn Consulting Corp, Ecol Tech Res Inst, Beijing 100085, Peoples R China.;[Chen, Xiaoyong] Governors State Univ, Coll Arts & Sci, One Univ Pkwy, University Pk, IL 60484 USA.
通讯机构：
[Wende Yan] N;[Xiaoyong Chen] C;National Engineering Laboratory for Applied Forest Ecological Technology in Southern China, College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, China<&wdkj&>College of Arts and Sciences, Governors State University, University Park, USA
关键词：
Phosphorus fractions;Evergreen broad-leaved forest;Chinese fir plantation;Seasonal patterns
通讯机构：
[Zhang, X; Yan, WD ] C;Cent South Univ Forestry & Technol, Fac Life Sci & Technol, Changsha 410004, Peoples R China.;Natl Engn Lab Appl Technol Forestry & Ecol South C, Changsha 410004, Peoples R China.;Key Lab Urban Forest Ecol Hunan Prov, Changsha 410004, Peoples R China.;Lutou Natl Stn Sci Observat & Res Forest Ecosyst, Yueyang 414000, Peoples R China.
关键词：
CO2 flux;urban;eddy covariance;footprint model
摘要：
Understanding the spatial and temporal variations of urban carbon dioxide fluxes (F-CO2) and their influencing factors is crucial for solving urban climate problems and promoting the development of low-carbon cities. In this study, the carbon dioxide flux (F-CO2) in Changsha City, China, was analyzed using the eddy covariance technique and flux footprint model. The results showed that the extent of the flux footprint within the observation site was mostly limited to 500 m. Diurnal variation of F-CO2 showed a regular pattern influenced by plant photosynthesis and traffic flow. Meanwhile, photosynthesis was directly regulated by photosynthetically active radiation and indirectly regulated by air temperature and water vapor pressure differences. The average value of F-CO2 was lower during the daytime than at night, indicating the high vegetation cover (43.5%) in the study area. In addition, there were spatial characteristics of F-CO2 in each wind direction due to different surface land use in the study area. Notably, a decreasing trend in carbon dioxide content was observed after the area covered by vegetation was 1.8 times the area of buildings and major roads combined. These findings guide climate management, urban planning, and sustainable development toward a low-carbon society.
期刊：
Industrial Crops and Products,2023年198:116679 ISSN：0926-6690
通讯作者：
Hanjie He<&wdkj&>Wende Yan
作者机构：
[Sun, Wenkai; He, Hanjie; Zhang, Xuejing; Yan, Wende; Chen, Lili] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Natl Engn Lab Appl Technol Forestry & Ecol South C, Hunan Prov Key Lab Forestry Biotechnol,Int Coopera, Changsha 410004, Hunan, Peoples R China.;[Chen, Xiaoyong] Governors State Univ, Coll Arts & Sci, University Pk, IL 60484 USA.;[Lv, Zhencheng] Huizhou Univ, Sch Life Sci, Huizhou 516007, Guangdong, Peoples R China.
通讯机构：
[Hanjie He; Wende Yan] N;National Engineering Laboratory for Applied Technology of Forestry ＆ Ecology in South China/Hunan Provincial Key Laboratory of Forestry Biotechnology/International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology, College of Life Sciences and Technology, Central South University of Forestry ＆ Technology, Changsha 410004, Hunan, China
摘要：
Werevealed the spatial distribution patterns of soil MPsand their correlation with environmental and social factors in urbanwetlands. Microplastics (MPs), as a new persistent pollutant, canbe emittedand accumulated in urban environments, but there is no detailed informationon the driving factors of MP pollution. In this study, through a large-scalewetland soil survey, the features of MPs were characterized in eachurban area. The results showed an average abundance to be 379 n/kgin wetland soil. Polypropylene, fiber or fragment, and black colorwere common composition, shape, and color, respectively. The spatialdistribution information showed that MP abundance was significantlyrelevant to the distance from the urban economic center. Furthermore,the correlation and regression analysis revealed that MP abundancewas related to soil heavy metal and atmospheric particle (PM10 and PM2.5) concentrations (P < 0.05),while the promotion of socioeconomic activities (urbanization level,population density, etc.) may aggravate the pollution degree. Additionally,by using structural equation modeling, it was found that the urbanizationlevel was the dominant factor driving the MP pollution degree, witha total effect coefficient of 0.49. Overall, this work provides multi-sidedenvironmental information regarding MP pollution in urban ecosystems,which is significant for follow-up studies of MP pollution controland restoration.
通讯机构：
[Yong Li] N;National Engineering Laboratory for Applied Forest Ecological Technology in Southern China, Laboratory of Urban Forest Ecology of Hunan Province, College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China
摘要：
The increased emission and accumulation of micro- or nanoplastics (M-NPs) have posed a severely threaten to organisms in the environment. Though the toxicity of M-NPs has been observed in many species, the fundamental factors determining the biotoxicity are rarely expounded on. In this work, typical polystyrene (PS) M-NPs were set up with a multiparameter variation in size gradient, surface charge contrast and concentration variant, and evaluated by the Caenorhabditis elegans (C. elegans) model. From the endpoints of body length, brood size, survival rate and lifespan, an adverse effect was found on the growth and development of C. elegans caused by PSs. In general, the toxicity of PS was found to be concentrated- and size-dependent, with 100 nm positively charged nano-PS having the highest physio-toxicity. Monitoring by fluorescent imaging, it showed that positively charged nano-PS was mainly ingested and accumulated in the intestinal tract of C. elegans. In addition, the penetrated PS induced severe biological stress reactions with the increase of reactive oxygen species (ROS) and lipofuscin. Furthermore, the following expression of antioxidation-related enzymes was activated in vivo as indicated by the GFP-labelled C. elegans. All the results supplied visually toxic parameters of M-NPs to organisms, which sheds light on the biosecurity and ecological risks of M-NPs in the future.
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.
