摘要：
Introduction The Dicranopteris dichotoma fern community plays vital roles in nutrient sequestration, succession regulation, and ecological threshold control. However, the mechanisms underlying the formation of the D. dichotoma-dominant community remain unclear.Methods This study established four different community types to investigate the effects of environmental factors on the formation of a D. dichotoma-dominant community.Results We found that climate was the primary factor affecting the formation of patches dominated by D. dichotoma at the regional scale. Specifically, higher annual mean temperature and annual mean precipitation were associated with larger single-dominant-species patches of D. dichotoma. Understory light intensity was the major factor affecting the formation of the D. dichotoma community at the community scale. Light intensity ranging from 200 to 500 mu mol<middle dot>m(-)(2)<middle dot>s(-)(1) was most conducive to the development of a large D. dichotoma community. Additionally, understory light intensity enhanced the importance value of D. dichotoma in the herb community by decreasing its biomass proportion of support modules and increasing its biomass proportion of photosynthetic and reproductive modules. Soil properties and D. dichotoma characteristics showed interactions with each other. Acidic red-yellow soil was most suitable for the formation of single-dominant-species patches of D. dichotoma, and the growth of D. dichotoma further decreased the soil pH. Soil total phosphorus content was identified as a limiting factor for formation of the D. dichotoma community.Discussion In summary, the formation of single-dominant-species patches of D. dichotoma is mainly influenced by a combination of climate, community, and soil.
关键词：
Chinese fir plantation;Microbial residue nitrogen;Nitrogen fraction;Hydrolase activity;Stand age
摘要：
Microbial growth, metabolism, and reproductive activities have a significant role in the generation, transformation, and storage of soil nitrogen (N). However, the time-integrated effect of microorganisms on long-term N sequestration in plantation forests remains poorly understood. We investigated the microbial residue N (MRN) and its contribution to soil total N (TN) among the young (8-year), middle (16-year), near-mature (24-year), mature (34-year), and over-mature (106-year) stands of Chinese fir plantation (CFP) in subtropical China. The soil TN content showed a general pattern of increasing with stand age, ranging from 2.61 to 3.42 g k(-1) , and was higher in the over-mature and mature stands than in the other three stands (p p < 0.001). In addition, soil carbon (C), N, phosphorus (P), and hydrolase stoichiometric ratios indicated that P limitation was widespread during all stages of CFP development. The average ratio of soil fungal residue N (FRN) to bacterial residue N (BRN) was 3.64:1. The MRN content and its contribution to soil TN exhibited a falling and then rising pattern from young to over-mature stands, ranging from 1.24 to 1.70 g kg(-1) and 38.8% to 57.5%, respectively. Soil N fraction contents and hydrolase activities were higher in the 0-5 cm soil layer than in the 5-30 cm soil layer (p p < 0.05). Regression analysis showed that soil MRN content increased with soil N fraction contents, C-N-P stoichiometric ratios, and hydrolase activities (p p < 0.001). Redundancy analysis and partial least squares path modeling revealed that soil available N (AN) and N hydrolase were the main factors affecting MRN accumulation. These parameters may partially indicate the dynamics of MRN accumulation. Our study discovered that the long-term development of CFP promotes soil N sequestration, with microbial residues playing a significant role in contributing to N pools.
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.
摘要：
Purpose This study aims to evaluate the impact of peanut straw mulching on the N change and the functional genes in Camellia oleifera intercropping systems. Methods A field experiment with different types of straw mulch treatments (conventional tillage, whole, and crushed) and timing was (50 d and 150 d) established between 2018-2022; the soil N fractions, N transformation rates, the abundance and dominant species compositions of ammonia-oxidizing archaea (AOA), nirK, and nirS-harboring genes were investigated. Results The whole peanut straw mulching of 150 d significantly improved (P < 0.05) the content of soil microbial biomass N (MBN), ammonia N (NH4+), and nitrate N (NO3-). The soil nitrification and ammonification rates increased by 96.8% and 132% in the 150 d of peanut crushed and whole straw mulching, respectively. Notably, the peanut straw mulching of 50 d mainly affects the diversity and relative abundance of AOA while the soil nirK and nirS-harboring genes were affected by 150 d crushed and whole peanut straw mulching, respectively. Redundancy analysis showed that crushed and whole peanut straw mulching affects nitrate reductase as the primary factor in regulating the soil N cycle via functional genes and soil variables. Conclusions Long-term whole peanut straw or whole and crushed mixed straw mulching could hence be recommended to dryland farming communities to increase the soil N cycle and crop productivity in the C.oleifera-peanut intercropping system.
摘要：
Aims The general aim of the study is to provide insight into the importance of functioning maintenance of forest ecosystems. Specifically, the aim of the study is to assess the response of soil protist diversity, composition and co-occurrence network to varying degree of decomposition of fallen wood when compared to conventional soil. Methods A total of 24 samples of soil and fallen wood were collected from subtropical broad-leaved forests in China. Here we use a correlative approach to link the community of soil protists with fallen wood at different decomposition stage and compare with fallen-wood-free soil. The indicators of protists community were assessed using DNA metabarcoding of the 18S rRNA (Illumina sequencing). Results The biodiversity of soil protists tended to increase as decomposition advanced and pronounced difference was found between severe and moderate decomposition stages (P < 0.05). The decomposition of fallen wood had a significant effect on the composition of the soil protist community (Adonis: R-2 = 0.24, P < 0.01), and enhanced the complexity and stability of the co-occurrence network of soil protists. Soil protists exhibited a stronger association with fallen wood (11 significant linkages), compared to soil (7 significant linkages). Fallen wood decomposition indirectly affected the soil protist community through multiple ways. Conclusions Retention of fallen wood helps maintain the richness and interaction of soil protists. Future research directions should focus on specific mechanisms for how fallen wood decomposition affects protists. Our work may contribute to better guide forest management policies in China.
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：
<jats:p>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.</jats:p>
摘要：
<jats:p>It is well established that forest type can have a profound impact on soil physicochemical properties but the associated changes in soil microbial communities and the mechanisms by which soil quality is improved by various plantations are not fully understood. In this study, soil physicochemical properties and microbial and enzyme activities were investigated in four forest types–Castanopsis hystrix pure forests (CHPF), C. hystrix–Pinus elliottii mixed forests (CHPEF), C. hystrix–Michelia macclurei mixed forests (CHMMF), and C. hystrix–Mytilaria laosensis mixed forests (CHMLF) in the subtropical region of China. The purpose of this study was to assess the effects of afforestation types on characteristics of soil–its physical, chemical, and biological properties. The results showed that the contents of soil total organic carbon (TOC), soil total nitrogen (TN), microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN) were significantly improved in both CHMMF and CHMLF mixed forest stands when compared to the CHPF pure stand. Soil enzyme activities were enhanced in the mixed forests. In particular, high phosphatase activity was observed in CHMLF stands, leading to the transformation of soil phosphorus to available phosphorus in this forest type. Our study demonstrated that the broad–leaved mixed forests, but not coniferous mixed forests, could significantly improve soil quality in the study region. Our research provides a scientific insight into the promotion of vegetation restoration and plantation forest management in plantation regions of subtropical areas.</jats:p>
作者机构：
[Wu, Qian; Wang, Enwen] Anshun Univ, Fac Resources & Environm Engn, Anshun 561000, Peoples R China.;[Zheng, Wei; Yan, Wende; Rao, Chengjiao] Cent South Univ Forestry & Technol, Fac Life Sci & Technol, Changsha 410004, Peoples R China.;[Zheng, Wei; Yan, Wende; Rao, Chengjiao] Natl Engn Lab Appl Technol Forestry & Ecol South, Changsha 410004, Peoples R China.
通讯机构：
[Wei Zheng] N;National Engineering Laboratory for Applied Technology of Forestry & Ecology in South China, Changsha 410004, China<&wdkj&>Faculty of Life Science and Technology, Central South University of Forestry & Technology, Changsha 410004, China<&wdkj&>Author to whom correspondence should be addressed.
作者：
Farooq, Taimoor Hassan;Xen Xincheng;Shakoor, Awais;Rashid, Muhammad Haroon U.;Bashir, Muhammad Farhan;...
期刊：
Environmental Science and Pollution Research,2022年29(7):10250-10262 ISSN：0944-1344
通讯作者：
Yan, W.;Farooq, T.H.
作者机构：
[Farooq, Taimoor Hassan] Bangor Coll China, Changsha 410004, Peoples R China.;[Farooq, Taimoor Hassan; Yan, Wende; Xen Xincheng] Cent South Univ Forestry & Technol, Natl Engn Lab Appl Technol Forestry & Ecol South, Changsha 410004, Peoples R China.;[Shakoor, Awais] Univ Lleida, Dept Environm & Soil Sci, Avinguda Alcalde Rovira Roure 191, Lleida 25198, Spain.;[Rashid, Muhammad Haroon U.] Cent South Univ Forestry & Technol, Coll Forestry, Changsha 410000, Hunan, Peoples R China.;[Bashir, Muhammad Farhan] Cent South Univ, Business Sch, Changsha 410083, Peoples R China.
通讯机构：
[Taimoor Hassan Farooq] B;[Wende Yan] N;Bangor College China, a Joint Unit of Bangor University and Central South University of Forestry and Technology, Changsha, China<&wdkj&>National Engineering Laboratory for Applied Technology in Forestry and Ecology in South China, Central South University of Forestry and Technology, Changsha, China<&wdkj&>National Engineering Laboratory for Applied Technology in Forestry and Ecology in South China, Central South University of Forestry and Technology, Changsha, China
关键词：
C pools;Biomass production;Macronutrients;Trace elements;Nutrient enrichment;Forest ecosystem;Sub-tropical zone
摘要：
Exotic pine trees are often introduced to novel places worldwide. How exotic pines interact with local microbial communities, such as symbiotic ectomycorrhizal (ECM) fungi, during early establishment compared to interactions by their native counterparts remains to be examined in detail. In this study, native masson pine (Pinus massoniana) and exotic slash pine (Pinus elliottii) seedlings were grown in field-collected soil cores. ECM root tips were collected 3- and 6-months after planting and fungi were identified using high-throughput sequencing. We found that host identity was a key factor determining ECM fungal community assembly after 3-months: native pines associated with Rhizopogon while exotic pines associated primarily with ECM generalists. After 6-months growth, however, ECM fungal communities in native and exotic pines were both dominated by Rhizopogon species. We also found that host selections of several pioneer ECM fungi shared by both native and exotic pines may facilitate an exotic pine's establishment. These findings indicate that more attention should be paid to ECM fungal community shuffling by exotic trees during early establishment and, in turn, the influence of the potential changes in ECM fungal communities on local forest ecosystems.
作者机构：
[Wang, Jiaolong; Yan, Wende; Ning, Chen] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha 410004, Peoples R China.;[Yan, Wende; Ning, Chen; Chen, Xiaoyong] Natl Engn Lab Appl Technol Forestry & Ecol South, Changsha 410004, Peoples R China.;[Gsell, Timothy; Chen, Xiaoyong] Governors State Univ, Coll Arts & Sci, University Pk, IL 60484 USA.
通讯机构：
[Yan, Wende] C;[Yan, Wende] N;[Chen, Xiaoyong] G;Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha 410004, Peoples R China.;Natl Engn Lab Appl Technol Forestry & Ecol South, Changsha 410004, Peoples R China.
关键词：
Polycyclic aromatic hydrocarbons;Artificial root exudates;Koelreuteria Paniculata;Phenanthrene;Bacterial community structure
摘要：
Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants that represent a serious threat to the health of humans and ecosystems. The effects of plant root and artificial root exudates (ARE) on the biodegradation of phenanthrene (PHE) and their impact on soil bacterial community structure was the focus of this work using four treatments for 180 days. Treatments included; control treatment (CK), low concentration of ARE (AREL), high concentration of ARE (AREH), and planting Koelreuteria paniculata saplings (KOE). The diversity and composition of soil bacterial community were analyzed using highthroughput sequencing. The results showed that KOE treatments had the most significant effect on the biodegradation of PHE compared to controls. ARE treatments had the similar effects on the biodegradation of PHE in soil with high efficiency in AREH than AREL. Both KOE and ARE treatments reduced diversity of bacterial community but increased the abundance of PAHs degrading bacterial populations within representative phyla, including Proteobacteria and Firmicutes. During the study, the total bacterial OTUs showed the number of unique genus types initially increased, then lowered in the later stages of the incubation process. Specific bacterial populations enriched by the treatments and supported by the exudates seemed to determine the biodegradation of PHE and not the overall bacterial diversity. (C) 2020 Elsevier Ltd. All rights reserved.
作者机构：
[闫文德; 颜成正] College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, 410004, China;[郑文革] Beijing General Station of Soil and Water ConservationBeijing 100036, China;[王忠诚; 贾剑波] College of Forestry, Central South University of Forestry and Technology, Changsha, 410004, China;[贾国栋] College of Water and Soil Conservation, Beijing Forestry UniversityBeijing 100083, China
关键词：
冠层气孔导度;土壤含水量;液流密度;水汽压亏缺
摘要：
建立了不同控水条件下(无降水、一半降水、自然降水和二倍降水)的侧柏样地,于2016年8月—2017年8月监测了样地土壤含水量(SWC)、降水量、液流密度(Js)、叶面积指数(LAI)和水汽压亏缺(VPD)等因子,分析SWC对侧柏冠层气孔导度(gs)的影响。结果表明: 一半、自然和二倍降水样地的SWC与降水量呈正相关,SWC变化范围分别为4.9%～16.0%、7.2%～22.9%、7.4%～29.6%,无降水样地的SWC在8—10月下降50%;7月的日gs在14:00达到峰值(166.64 mmol·m-2·s-1),显著高于其他月份,且出现双峰现象, 1月的日gs在12:00达到峰值(54.1 mmol·m-2·s-1);3个降水条件下,侧柏gs与SWC呈负二次相关关系,且gs达到峰值,对应的SWC分别为8.5%、12.5%和18.5%,均趋近于年平均SWC。不同控水样地内侧柏gs对VPD的敏感性(δ)/参比冠层气孔导度(gsref)均≥0.6,表明不同控水条件下土壤水分状况较适合侧柏蒸腾用水的需求。当SWC在3.7%～7.5%时,δ和gsref值迅速增大,说明气孔调节能力更好,植物气孔对VPD的响应更敏感;当SWC上升到11%时,SWC变化对gsref和gs对VPD响应敏感性的影响不显著。可能存在侧柏产生适应状态的SWC阈值,植物体在自身的生命活动中关闭或减小气孔开度,降低叶片水势以适应过高的VPD,保护植物不会引起过度蒸腾,从而对蒸腾的调控更加有效。.A water-controlled experiment with four treatments (no rain, half raining, natural raining and double raining) was carried out in a Platycladus orientalis forest. The factors including soil water content (SWC), precipitation, sap flow density (Js), leaf area index (LAI), vapor pressure deficit (VPD) were monitored during August 2016 to August 2017. We further analyzed the response of canopy stomatal conductance (gs) to changes of SWC. The results showed that the SWC of plots (half, natural and double raining) showed a positive correlation with precipitation, and the range of SWC was 4.9%-16.0%, 7.2%-22.9%, 7.4%-29.6%, respectively. The SWC in the plot with no rain decreased by 50% from August to October. The daily gs reached a peak of 166.64 mmol·m-2·s-1 at 14:00 in July, which was significantly higher than other months. A bimodal phenomenon occurred. The daily gs reached a peak of 54.1 mmol·m-2·s-1 at 12:00 in January. Under the three rain plots, diurnal variation of gs and SWC showed a negative quadratic correlation. The SWC corresponding to the peak of gs was 8.5%, 12.5% and 18.5%, respectively, close to the annual average SWC. Sensitivity (δ) of gs to VPD /reference canopy stomatal conductance (gsref) was more than or equal to 0.6 in different water-controlled plots, indicating that soil water condition was more suitable for water demand of P. orientalis. When SWC was between 3.7% and 7.5%, the δ and gsref increased rapidly, indicating that stomata had better regulation ability, and that plant stomata was more sensitive to VPD. When SWC increased to 11%, SWC alteration did not affect the response sensitivity of gsrefand gs to VPD. There might be a SWC threshold value for the adaptation of P. orientalis. By closing or reducing stomatal aperture, leaf water potential decreased, P. orientalis could adapt to excessive VPD and avoid excessive transpiration, which was more effective in regulating transpiration.
摘要：
Phellodendron chinense Schneid is an important Chinese herb with berberine and phellodendrine in stems and leaves, but with little information available on in vitro culture of this species. Disinfection of explants in 75% alcohol for 45 s, sterilization in 0.1% HgCl2 for 20 min, and submersion in 1.0 mol L-1 gibberellin3 (GA(3)) solution for 24 h was the optimal condition for seed germination. Murashige and Skoog's (MS) medium supplemented with 2.0 mg L-1 6-benzylaminopurine (6-BA) in combination with 1.5 mg L-1 1-naphthylacetic acid (NAA) was optimal for callus induction. MS medium supplemented with 2.0 mg L-1 6-BA was the appropriate medium for induction of adventitious shoots, and 1/2MS medium supplemented with 2.0 mg L-1 indole-3-butytric acid (IBA) and 0.5% active carbon was the optimal medium for root induction. The 15-d survival rate of regenerated plantlets after transplanting to basins containing perlite and peat moss (1:4) was greater than 80%, and the berberine and phellodendrine accumulation was lower in callus compared with regenerated plantlets. The establishment of highly efficient regeneration system provides technical support for genetic breeding of Phellodendron chinense Schneid.
作者：
Ning, Chen*;Xiang, Wenhua;Mueller, Gregory M.;Egerton-Warburton, Louise M.;Yan, Wende;...
期刊：
Plant and Soil,2020年446(1-2):179-193 ISSN：0032-079X
通讯作者：
Ning, Chen
作者机构：
[Liu, Shuguang; Xiang, Wenhua; Yan, Wende; Ning, Chen] Cent South Univ Forestry & Technol, Fac Life Sci & Technol, 498 Southern Shaoshan Rd, Changsha 410004, Peoples R China.;[Ning, Chen] Northwestern Univ, Program Plant Biol & Conservat, Evanston, IL 60208 USA.;[Mueller, Gregory M.; Egerton-Warburton, Louise M.] Chicago Bot Garden, Chicago, IL 60022 USA.
通讯机构：
[Ning, Chen] C;Cent South Univ Forestry & Technol, Fac Life Sci & Technol, 498 Southern Shaoshan Rd, Changsha 410004, Peoples R China.
关键词：
Community structure and function;Ectomycorrhizal fungi;Extracellular enzyme;Exotic pine;Rhizopogon;Russula
