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Differential Responses of Nitrifier and Denitrifier to Dicyandiamide in Short- and Long-Term Intensive Vegetable Cultivation Soils

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Journal of Integrative Agriculture 2014年第5期13卷 1090-1098页

作者： LIU Yi YANG Yang QIN Hong-ling ZHU Yi-jun WEI Wen-xue Key Laboratory of Agro-Ecological Processes in Subtropical Regions and Taoyuan Station of Agro-ecology Research Institute of Subtropical Agriculture Chinese Academy of Sciences Tianjin Land & resources & Housing management Research Centre

Nitrification inhibitors, such as dicyandiamide （DCD）, have been shown to decrease leaching from urea- and ammoniumbased fertilizers in agricultural soils. The effect of nitrification inhibitors on nitrifier and denitrifier in short- and long-term intensive vegetable cultivation soils was poorly understood. In this study, the pot trial was conducted to investigate the differential responses of nitrifier （amoA-containing bacteria） and denitrifier （nirK-containing bacteria） to DCD in short-（soil S） and long-term （soil L） intensive vegetable cultivation soils. Quantitative polymerase chain reaction （qPCR） and terminal restriction fragment length polymorphism （T-RFLP） were employed to detect the abundance and composition of amoA- and nirK-containing communities. The results indicated that application of DCD led to a consistently higher NH4＋-N concentration during the whole incubation in soil L, while it was quickly decreased in soil S after 21 days. Furthermore, DCD induced more severe decrease of the abundance of amoA-containing bacteria in soil L than in soil S. However, the abundance of the nirK- containing community was not significantly affected by DCD in both soils. Long-term vegetable cultivation resulted in a super-dominant amoA-containing bacteria group and less divergence in soil L compared with soil S, and DCD did not cause obvious shifts of the composition of ammonia-oxidising bacteria （AOB）. On the contrary, both amoA- and nirK-containing bacterial compositions were influenced by DCD in soil S. The results suggested that long-term intensive vegetable cultivation with heavy nitrogen fertilization resulted in significant shifts of AOB community, and this community was sensitive to DCD, but denitrifiers were not clearly affected by DCD.

关键词： DCD amoA nirK vegetable soil

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Journal of Forestry Research 2020年第6期31卷 2435-2444页

作者： Yunyun Wang Jalene M.La.Montagne Fei Lin Zuoqiang Yuan Ji Ye Xugao Wang Zhanqing Hao CAS Key Laboratory of Forest ecology and management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016People’s Republic of China department of Biological Sciences DePaul UniversityChicagoIL 60614USA

Seed distribution and deposition patterns around parent trees are strongly aff ected by functional traits and therefore infl uence the development of plant *** assess the limitations of seed dispersal and the extent to which diaspore and neighbouring parental traits explain seed rain,we used a 9-year seed data set based on 150 seed traps in a 25-ha area of a temperate forest in the Changbai *** 480,598 seeds belonging to 12 families,17 genera,and 26 species were identifi ed,only 54%of the species with mature trees in the community were represented in seeds collected over the 9 years,indicating a limitation in seed *** species were most limited;overstory species were least *** with wind-dispersed seed had the least limitation,while the lowest similarity in species richness was for animal-dispersed species followed by gravity-dispersed species;fl eshy-fruited species had stronger dispersal limitations than dry-fruited *** linear mixed models showed that relative basal area had a signifi cant positive eff ect on seed abundance in traps,while the contribution of diaspore traits was low for nearly all *** results suggest that tree traits had the strongest contribution to seed dispersal and deposition for all functional groups examined *** fi ndings strengthen the knowledge that tree traits are key in explaining seed deposition patterns,at least at the primary dispersal *** improved knowledge of sources of seeds that are dispersed could facilitate greater understanding of seedling and community dynamics in temperate forests.

关键词： Seed rain Dispersal mechanisms Tree traits Basal area Changbai mountain Temperate forest

Assessing the health and ecological security of a human induced watershed in central iran

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Ecosystem Health and Sustainability 2022年第1期8卷 421-435页

作者： Seyed Hamidreza Sadeghi Mehdi Vafakhah Vahid Moosavi Sanaz Pourfallah Asadabadi Padideh Sadat Sadeghi Abdulvahed Khaledi Darvishan Reza Bagheri Fahraji Seyed Hossein Mosavinia Abdolghasem Majidnia Sudabeh Gharemahmudli Hamidreza Moradi Rekabdarkolaei department of Watershed management Engineering Faculty of Natural ResourcesTarbiat Modares UniversityNoorMazandaranIran General department of Natural resources and Watershed management YazdIran Watershed management Engineering and Science Gorgan University of Agricultural SciencesGorganGolestanIran

Assessment of the watershed health and associated ecological security is crucial for the proper land resources management,notably when sufficient money and time have *** present study aimed to prepare health and ecological security for the Pishkuh Watershed in Yazd Province,central *** prepare the health atlas of the Pishkuh Watershed,the conceptual framework of pressure,state,response(PSR)was *** pressure index was investigated by analyzing the driving forces of natural and human-induced ***,the existing conditions of the natural environment and the watershed performance were analyzed using the state ***,the response index was also calculated as a criterion for expressing the degree of community response or different watershed outcomes to the driving forces imposed on the watershed *** study results revealed that some 91 and 9%of the watershed were classified as moderately healthy and relatively *** results of the ecological security index further showed that some 41%of the area was categorized as relatively poor *** results of the current study can be used by local managers and decision-makers to adaptively designate appropriate,economic,and goal-targeted solutions for the resources management in the region.

关键词： Adaptive management Integrated watershed management Land management Sustainable development Watershed sustainability

Changing institutions for environmental policy and politics in New Era China

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Chinese Journal of Population,resources and Environment 2018年第3期16卷 242-251页

作者： Lei Zhang Xiaoran Li department of Environment and resources management School of Environment and Natural Resources Renmin University of China

The evolution of Chinese environmental policy and politics can be better understood in the broader context of institutional changes that have taken place since the late 1970s. In this study,an analytical framework was established to analyze how overall institutional changes were reflected in the roles of relationships between governmental and non-governmental actors engaged in environmental governance. Institutional changes were observed at three levels:informal institutions(cultural traditions, and political ideology); formal institutions(the polity,political system, property rights, and judiciary); and governing mechanisms(structures, regulatory approaches, and incentives). This analysis of interactions between institutional changes and the changing environmental process explained not only the drives and constraints behind China's environmental policy evolution so far but also shed light on future challenges and opportunities.

关键词： Institutional changes environmental politics new environmentalism New Era China

Effects of ultraviolet(UV) radiation and litter layer thickness on litter decomposition of two tree species in a semi-arid site of Northeast China

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Journal of Arid Land 2018年第3期10卷 416-428页

作者： MAO Bing ZHAO Lei ZHAO Qiong ZENG Dehui CAS Key Laboratory of Forest ecology and management Institute of Applied Ecology Chinese Academy of Sciences College of Horticulture Jilin Agricultural University Daqinggou Ecological Station Institute of Applied Ecology Chinese Academy of Sciences

Forests and grasslands in arid and semi-arid regions receive high-intensity ultraviolet（UV） radiation year-round. However, how the UV radiation affects the litter decomposition on the forest floor remains unclear. Here, we conducted a field-based experiment in 2011 in the southeastern Horqin Sandy Land, Northeast China, to investigate the effects of UV radiation, litter layer thickness, and their interaction on the mass loss and chemical properties of decomposing litter from Xiaozhuan poplar（Populus × xiaozhuanica） and Mongolian pine（Pinus sylvestris var. mongolica） plantation trees. We found that UV radiation accelerated the decomposition rates of both the Xiaozhuan poplar litter and Mongolian pine litter. For both species, the thick-layered litter had a lower mass loss than the thin-layered litter. The interaction between UV radiation and litter layer thickness significantly affected the litter mass loss of both tree species. However, the effects of UV radiation on the chemical properties of decomposing litter differed between the two species, which may be attributed to the contrasting initial leaf litter chemical properties and morphology. UV radiation mostly had positive effects on the lignin concentration and lignin/N ratio of Xiaozhuan poplar litter, while it had negative effects on the N concentration of Mongolian pine litter. Moreover, litter layer thickness and its interaction with UV radiation showed mostly positive effects on the N concentration and lignin/N ratio of Xiaozhuan poplar litter and the ratios of C/N and lignin/N of Mongolian pine litter, and mostly negative effects on the C/N ratio of Xiaozhuan poplar litter and the N concentration of Mongolian pine litter. Together, these results reveal the important roles played by UV radiation and litter layer thickness in the process of litter decomposition in this semi-arid region, and highlight how changes in the litter layer thickness can exert strong influences on the photodegradation of litter in tre

关键词： lignin litter decomposition litter layer thickness nitrogen forest plantation photodegradation UV radiation

Retention of harvest residues promotes the accumulation of topsoil organic carbon by increasing particulate organic carbon in a Chinese fir plantation

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Forest Ecosystems 2024年第5期11卷 720-727页

作者： Jiamin Yang Ke Huang Xin Guan Weidong Zhang Renshan Li Longchi Chen Silong Wang Qingpeng Yang Huitong Experimental Station of Forest ecology CAS Key Laboratory of Forest Ecology and ManagementInstitute of Applied EcologyShenyang110016China Huitong National Research Station of Forest Ecosystem Hunan Key Laboratory for Structure and Ecosystem Service of Subtropical ForestHuaihua418307China Life Science department Luoyang Normal UniversityLuoyang471934China College of resources and Environment University of Chinese Academy of SciencesBeijing101408China

Background As commonly used harvest residue management practices in subtropical plantations,stem only harvesting(SOH)and whole tree harvesting(WTH)are expected to affect soil organic carbon(SOC)***,knowledge on how SOC and its fractions(POC:particulate organic carbon;MAOC:mineral-associated organic carbon)respond to different harvest residue managements is *** In this study,a randomized block experiment containing SOH and WTH was conducted in a Chinese fir(Cunninghamia lanceolata)*** effect of harvest residue management on SOC and its fractions in topsoil(0–10cm)and subsoil(20–40cm)was *** inputs(harvest residue retaining mass and fine root biomass)and microbial and mineral properties were also *** The responses of SOC and its fractions to different harvest residue managements varied with soil ***,SOH enhanced the content of SOC and POC in topsoil with increases of 15.9%and 29.8%,respectively,compared with ***,SOH had no significant effects on MAOC in topsoil and SOC and its fractions in *** results indicated that the increase in POC induced by the retention of harvest residue was the primary contributor to SOC accumulation,especially in *** harvest residue managements affected SOC and its fractions through different pathways in topsoil and *** plant inputs(the increase in fine root biomass induced by SOH)exerted a principal role in the SOC accumulation in topsoil,whereas mineral and microbial properties played a more important role in regulating SOC dynamics than plants inputs in *** The retention of harvest residues can promote SOC accumulation by increasing POC,and is thus suggested as an effective technology to enhance the soil carbon sink for mitigating climate change in plantation management.

关键词： Chinese fir plantation Soil organic carbon Particulate organic carbon Mineral-associated organic carbon Harvest residue management

Water quality, habitat, and fish assemblage relationships in middle-order agriculture and forest streams of the Mississippi Alluvial Plain

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Ecological Processes 2024年第1期13卷 217-236页

作者： Matthew L.Skoog Michael A.Eggleton Yushun Chen department of Aquaculture and Fisheries University of Arkansas at Pine Bluff Minnesota department of Natural resources State Key Laboratory of Freshwater ecology and Biotechnology Institute of Hydrobiology Chinese Academy of Sciences University of Chinese Academy of Sciences

Background Agriculture has greatly influenced water quality, habitats, and fish assemblages in streams of the Mississippi Alluvial Plain(MAP) ecoregion. However, MAP streams have historically been understudied compared to streams in other agricultural regions of the USA. In this study, water quality, habitat, and fish assemblage composition were assessed seasonally(spring, summer, and fall) in eight representative MAP streams located across three U.S. states. The study design included four streams containing highly agricultural watersheds(herein termed “agriculture” streams) and four streams containing mostly forested watersheds(herein termed “forest” streams), which were intended to represent reference conditions for MAP *** In general, forest streams contained significantly better instream and riparian habitats than agriculture streams(P = 0.010–0.040) whereas agriculture streams contained significantly greater levels of primary nutrients(P < 0.001–0.010). Differences between agriculture and forest streams with respect to other physical and chemical variables were intermittent and season dependent. Fish assemblages in agriculture and forest streams were structured primarily along an environmental gradient reflecting instream habitat conditions, water nutrient concentrations, and benthic chlorophyll-a production. Structurally, fish assemblages in both stream types contained many regionally common species, though some species appeared to exhibit affinities for a particular stream type. Functionally, fish assemblages in agriculture streams contained more tolerant species, more omnivores, and fewer insectivores compared to forest stream assemblages, which were nearly all insectivores. Overall, one-third of the fish specimens collected in forest streams classified as intolerant *** Our results suggested that stream water quality, habitat, and fish assemblages differed between agriculture and forest streams in the MAP, with fish assemblages e

关键词： Agriculture Stream Land use Water quality Habitat Fish Multivariate statistics Mississippi Alluvial Plain

Estimating oak forest parameters in the western mountains of Iran using satellite-based vegetation indices

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Journal of Forestry Research 2020年第2期31卷 541-552页

作者： Adel Nouri Bahman Kiani Mohammad Hossein Hakimi Mohammad Hossein Mokhtari department of Forest Sciences Faculty of Natural ResourcesYazd UniversityYazdIslamic Republic of Iran department of Desert management Faculty of Natural ResourcesYazd UniversityYazdIslamic Republic of Iran

Remote sensing is an important tool for studying and modeling forest *** indices obtained from Landsat-8 remotely sensed data were used to estimate the forest parameters in the western mountains of *** sample points were selected on the map of Bayangan County,Kermanshah province,*** each point,a cluster of five rectangular plots of 8100 m2 and 200 m apart was *** clusters were primarily sampled to determine the variance of the forest *** coefficient of variation was used as a criterion for sample *** density,canopy cover and basal area per hectare were calculated for each *** indices were extracted fromthe Landsat-8 images for each *** linear and nonlinear regressions were conducted to develop the *** models were validated using an independent data *** of model parameters was statistically *** results showed that Normalized difference vegetation index(NDVI)and Transformed normalized difference vegetation index(TNDVI)followed by Simple ratio vegetation index(SRVI)were the best predictors,explaining up to 91%of the variations with high *** NDVI,Soil adjusted vegetation index 2(SAVI2)and SRVI,the cubic model was more appropriate than the linear model for predicting the forest *** this model,the R-square value increased while NRMSE decreased *** Infrared percentage vegetation index(IPVI),the quadratic model was better,but,for other vegetation indices,nonlinear models were not superior to linear ***,it can be concluded that Landsat-8 imagery is suitable for predicting forest parameters in the oak forests of western *** course,large plots must be selected,and pre-classification is necessary to gain accurate and precise estimations.

关键词： Basal area Canopy cover Density Landsat-8 Modeling

Soil physical properties degrade further on skid trails in the year following operations

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Journal of Forestry Research 2018年第1期29卷 93-101页

作者： Ramin Naghdi Ahmad Solgi Eric K.Zenner Farshad Keivan Behjou department of Forestry Faculty of Natural Resources University of Guilan department of Ecosystem Science and management Penn State UniversityUniversity Park Faculty of Agricultural Technology and Natural resources University of Mohaghegh Ardabili

Short-term recovery of soil physical properties on skid trails was investigated upon cessation of skidding operations and 1 year later. Bulk density and porosity were assessed at three levels of traffic intensity and two slope gradients. Compared to undisturbed areas, bulk density increased, total porosity and macroporosity decreased, and microporosity increased in the compacted areas immediately after skidding. In all cases, changes were significantly greater when traffic intensity was higher and when slopes were steeper. Surface soil compaction did not show any recovery over the 1-year period, illustrating the persistent effects of compaction on soil structure. In fact, surficial compaction further increased and macroporosity further decreased after 1 year of recovery, compared to immediately after skidding. While these changes may reflect inherent small-scale site variability or differences in soil moisture content at times of sampling, direct negative physical impacts on newly exposed soil（such as by raindrops）, in addition to the loss of organic matter after canopy removal and skidding, likely delayed any physical recovery, particularly on heavily trafficked trails on steeper slopes. These results raise serious concerns about longterm resilience to traffic on forest soils and indicate the necessity to properly retire skid trails to avoid further soil degradation as trails age.

关键词： Compaction Porosity Recovery Skid trail slope Traffic frequency