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Vertical distribution patterns and drivers of soil bacterial communities across the continuous permafrost region of northeastern China

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Ecological Processes 2022年第1期11卷 38-50页

作者： Baihui Ren yuanman hu Rencang Bu Shenyang Agricultural University ShenyangChina CAS Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesNo.72Wenhua RoadShenyang 110016LiaoningChina

Background:Soil microorganisms in the thawing permafrost play key roles in the maintenance of ecosystem function and regulation of biogeochemical ***,our knowledge of patterns and drivers of permafrost micro-bial communities is limited in northeastern ***,we investigated the community structure of soil bacteria in the active,transition and permafrost layers based on 90 soil samples collected from 10 sites across the continuous permafrost region using high-throughput Illumina ***:Proteobacteria(31.59%),Acidobacteria(18.63%),Bacteroidetes(9.74%),Chloroflexi(7.01%)and Actinobacteria(6.92%)were the predominant phyla of the bacterial community in all soil layers;however,the relative abundances of the dominant bacterial taxa varied with soil *** bacterial community alpha-diversity based on the Shannon index and the phylogenetic diversity index both decreased significantly with depth across the transition from active layer to permafrost *** multidimensional scaling analysis and permutation multivariate analysis of variance revealed that microbial community structures were significantly different among *** analysis and Spearman’s correlation analysis showed that soil properties differed between layers such as soil nutrient content,temperature and moisture mainly drove the differentiation of bacterial ***:Our results revealed significant differences in bacterial composition and diversity among soil *** findings suggest that the heterogeneous environmental conditions between the three soil horizons had strong influences on microbial niche differentiation and further explained the variability of soil bacterial community *** effort to profile the vertical distribution of bacterial communities may enable better evaluations of changes in microbial dynamics in response to permafrost thaw,which would be beneficial to ecological conservation of permafrost ecosystems.

关键词： Permafrost Soil depth Bacterial community structure Soil properties Illumina sequencing

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Modelling the dead fuel moisture content in a grassland of Ergun City,China

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Journal of Arid Land 2023年第6期15卷 710-723页

作者： CHANG Chang CHANG Yu GUO Meng hu yuanman CAS Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China University of Chinese Academy of Sciences Beijing 100049China School of Geographical Sciences Northeast Normal UniversityChangchun 130024China E'erguna Wetland Ecosystem National Research Station Hulunbuir 022250China

The dead fuel moisture content(DFMC)is the key driver leading to fire *** estimating the DFMC could help identify locations facing fire risks,prioritise areas for fire monitoring,and facilitate timely deployment of fire-suppression *** this study,the DFMC and environmental variables,including air temperature,relative humidity,wind speed,solar radiation,rainfall,atmospheric pressure,soil temperature,and soil humidity,were simultaneously measured in a grassland of Ergun City,Inner Mongolia Autonomous Region of China in *** chose three regression models,i.e.,random forest(RF)model,extreme gradient boosting(XGB)model,and boosted regression tree(BRT)model,to model the seasonal DFMC according to the data *** ensure accuracy,we added time-lag variables of 3 d to the *** results showed that the RF model had the best fitting effect with an R2value of 0.847 and a prediction accuracy with a mean absolute error score of 4.764%among the three *** accuracies of the models in spring and autumn were higher than those in the other two *** addition,different seasons had different key influencing factors,and the degree of influence of these factors on the DFMC changed with time ***,time-lag variables within 44 h clearly improved the fitting effect and prediction accuracy,indicating that environmental conditions within approximately 48 h greatly influence the *** study highlights the importance of considering 48 h time-lagged variables when predicting the DFMC of grassland fuels and mapping grassland fire risks based on the DFMC to help locate high-priority areas for grassland fire monitoring and prevention.

关键词： dead fuel moisture content(DFMC) random forest(RF)model extreme gradient boosting(XGB)model boosted regression tree(BRT)model grassland Ergun City

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The spatiotemporal changes of marshland and the driving forces in the Sanjiang Plain, Northeast China from 1980 to 2016

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Ecological Processes 2020年第1期9卷 263-275页

作者： Zhen Li Miao Liu yuanman hu Zhenshan Xue Jinling Sui CAS Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China University of Chinese Academy of Sciences Beijing 100049China Research Center of Wetland Ecology and Environment Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102China Key Laboratory of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China

Background:Wetland loss is a global concern due to its enormous ecosystem ***,a typical natural wetland,which is concentrated in the Sanjiang Plain,has undergone dramatic loss in the last several *** spatiotemporal changes in marshland were studied based on Landsat images of the Sanjiang Plain from 1980 to 2016 with the land use maps in 1980,1995,2000,2005,2010,and 2016 using land use dynamic degree and landscape *** driving forces of marshland loss,including biophysical factors,socio-economic factors,and land management,were analyzed with boosted regression trees(BRTs)***:The area of marshland loss was 7372 km^(2),which accounted for 65.7%of the area of marshland in 1980;however,the paddy field area was expanded by 22,313 km^(2).The lost marshland was mainly converted to dry farmland(47.5%)and paddy field(47.2%)during *** the landscape pattern of the study area and marshland became increasingly *** relatively important factors responsible for marshland loss were biophysical factors,socio-economic factors,and land management,which accounted for 65.2%,25.5%,and 8.4%,*** most important driving forces with high“relative influence”were“distance to river,”which accounted for 20.6%of the total variance ***“relative influence”of potential crop yield and ditch density reached 20.2%and 8.4%,***:Significant land use changes have occurred in the Sanjiang Plain over the past 37 years,with characteristics of rapid paddy field expansion and drastic marshland ***,marshland fragmentation continued to *** was the main reason for the large-scale marshland *** factors influenced the decisions regarding the locations of marshland ***,climate factors(i.e.,average annual precipitation and average annual temperature)also played an important role in marshland *** results can provide helpful knowledge for understanding the patt

关键词： Land use change Marshland loss Driving forces The Sanjiang Plain

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Geographical Variation and Influencing Factors of Spartina alterniflora Expansion Rate in Coastal China

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Chinese Geographical Science 2020年第1期30卷 127-141页

作者： ZHANG Danhua hu yuanman LIU Miao CHANG Yu SUN Lishuang School of Transportation Engineering Shenyang Jianzhu UniversityShenyang 110168China Institute of Applied Ecology Chinese Academy of SciencesShenyang 110164China

Biological invasion poses a huge threat to ecological *** alterniflora was introduced into China in 1979,and its arrival corresponded with negative effects on native *** explore geographical variation of its expansion rate in coastal China,we selected 43 *** sites from Tianjin Coastal New Area to *** area expansion rate,expansion rate paralleling and vertical to the shoreline were analysed based on Landsat images and field survey in *** Ocean Data Assimilation(SODA)and climate data were collected to statistically analyse the influential factors of expansion *** showed that significant difference of *** area expansion rate among different latitude zones(P<0.01),increasing from 6.08%at southern(21°N–23°N)to 19.87% in Bohai Bay(37°N–39°N)along latitude *** was a significant difference in expansion rate vertical to shoreline in different latitude zones(P<0.01)with the largest occurring in Bohai Bay(256m/yr,37°N–39°N),and showed an decreasing tendency gradually from north to *** significant difference and latitudinal clines in expansion rate paralleling to shoreline were *** rate had significant negative correlation with mean seawater temperature,the lowest seawater temperature,current zonal velocity and meridional velocity and presented a reducing trend as these biotic factors increased;however,they were not significantly correlated with the highest seawater temperature and mean seawater *** identified significant correlations between expansion rate and annual mean temperature,the lowest temperature in January and annual precipitation,but there was little correlation with annual diurnal difference in temperature and the highest temperature in *** rapid expansion rate in high-latitude China demonstrated a higher risk of potential invasion in the north;dynamic monitoring and control management should be established as soon as possible.

关键词： geographical variation biological invasion Spartina alterniflora expansion rate coastal wetlands China

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Assessing outdoor air quality vertically in an urban street canyon and its response to microclimatic factors

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Journal of Environmental Sciences 2023年第2期124卷 923-932页

作者： Chunping Miao Shuai Yu Yue Zhang yuanman hu Xingyuan He Wei Chen CAS Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China Shenyang Arboretum Chinese Academy of SciencesShenyang 110016China

The vertical distribution of air pollutants in urban street canyons is closely related to residents’***,the vertical air quality in urban street canyons has rarely been assessed using field observations obtained throughout the ***,this study investigated the seasonal and annual concentrations of particulate matter(PM2.5 and PM10),CO,NO_(2),SO_(2),O_(3),air quality index,and their responses to microclimatic factors at three height levels(1.5,27,and 69 m above street level)in an urban street *** PM concentration was higher at 27 m than at 1.5 m in winter,whereas the situation was reversed in other *** was found that photochemical pollutants such as NO_(2) and O_(3) were the primary pollutants in the urban street *** days on which O3 was the primary pollutant at the height of 1.5 m accounted for 81.07% of the entire *** days on which NO_(2) was the primary pollutant at the height of 27 and 69 m accounted for 82.49% and 72.33%of the entire year,*** higher concentrations of NO2 and O_(3) were found at the height of 27 m than at 69 ***-canyon concentrations of NO_(2) and O_(3) were strongly correlated with air temperature,wind speed,and wind direction,which played important roles in photochemical reactions and pollutant dispersion.

关键词： Urban air pollution Built environment Urban form Urbanization

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Simulating Impact of Larch Caterpillar(Dendrolimus superans)on Fire Regime and Forest Landscape in Da Hinggan Mountains,Northeast China

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Chinese Geographical Science 2011年第5期21卷 575-586页

作者： CHEN Hongwei hu yuanman CHANG Yu BU Rencang LI Yuehui LIU Miao State Key Laboratory of Forest and Soil Ecology Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110164 China

Larch caterpillar (Dendrolimus superans) is very common in the Da Hinggan Mountains, Northeast China, affecting fire regime and forest ecosystem change at large spatio-temporal scales. In this study, we used a spatially explicit landscape model, LANDIS, to simulate the changes of fire regime and forest landscape under four larch caterpillar disturbance intensity levels scenarios in huzhong forest area, northern of Da Hinggan Mountains. The results indicate that larch caterpillar disturbances would decrease fine fuel load and increase coarse fuel load in the 300 simulation years. Larch caterpillar disturbances would decrease fire frequency in the first 200 years, and the disturbances also decrease fire intensity and fire risk in the early and late stage of simulation. Larch caterpillar disturbances would decrease the area percent of larch cohorts and increase the proportion of white birch, and increase the degree of aggregation of white birch as a result of its strong seed dispersal and colonization ability. Disturbances would also decrease the mature and over-mature larch cohorts and increase all cohorts of white birch, especially the mature and over-mature cohorts. Larch caterpillar disturbances will decrease the stability of forest landscape, therefore,some measures preventing in- sect outbreak and ensuring the sustainable management of forest ecosystem should been taken in the study area.

关键词： forest landscape larch caterpillar fire disturbance LANDIS model

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Changes of forest fire regime and landscape pattern under different harvesting modes in a boreal forest of Northeast China

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Journal of Arid Land 2015年第6期7卷 841-851页

作者： CHEN Hongwei hu yuanman CHANG Yu BU Rencang LI Yuehui LIU Miao Liaoning Key Laboratory of Urban Integrated Pest Management and Ecological Security Shenyang University State Key Laboratory of Forest and Soil Ecology Institute of Applied Ecology Chinese Academy of Sciences

Forest management such as timber harvesting shapes fire regimes and landscape patterns, and these patterns often differ significantly from those under natural disturbances. Our objective was to examine the effects of timber harvesting modes on fire regimes and landscape patterns in a boreal forest of Northeast China. We used a spatially explicit landscape model, LANDIS, to simulate the changes of forest landscape in the huzhong forest region of the Great Khingan Mountains under no-cutting, clear-cutting, gradual-cutting and selective-cutting modes. Results showed that：（1） the fine fuel loadings generally decreased while the coarse fuel loadings increased with the increase of timber harvesting intensity;（2） the potential burn area significantly varied among different cutting modes, but the potential fire frequency had no obvious difference. Moreover, timber harvesting generally increased the potential fire risk;（3） clear-cutting mode significantly decreased the mean patch size and the aggregation of larch forests and increased the mean patch size and the aggregation of white birch forests. Therefore, clear-cutting mode should be abandoned, and selective-cutting mode be recommended for the sustainable forest management in the Great Khingan Mountains.

关键词： LANDIS clear-cutting gradual-cutting selective-cutting Great Khingan Mountains

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Change of impervious surface area and its impacts on urban landscape:an example of Shenyang between 2010 and 2017

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Ecosystem Health and Sustainability 2020年第1期6卷 69-81,68页

作者： Wen Wu Chunlin Li Miao Liu yuanman hu Chunliang Xiu Jangho Architecture College Liaoning Provincial Key Laboratory of Urban and Architectural Digital TechnologyNortheastern UniversityShenyangChina Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyangChina

Introduction:One of the most striking features of urbanization is the replacement of the original natural land cover type by artificial impervious surface area(ISA).However,the extent of the contribution of various environmental factors,especially the growth of 3D space to ISA expansion,and the scope and mechanism of their influences in dramatically expanding cities,are yet to be *** boosted regression tree(BRT)model was adopted to analyze the main influencing factors and driving mechanisms of ISA change in Shenyang,China between 2010 and ***:The nearly complete-coverage ISA(≥0.7)increased from 42%in 2010 to 47%in *** percentage of landscape with a high ISA fraction increased,while the landscape evenness and diversity of ISA *** BRT analysis revealed that elevation,regional population density,and landscape class had the largest influences on the change of urban ISA,contributing 22.55%,18.16%,and 11.18%to the model,***:Overall,topographic and socioeconomic factors had the greatest influence on urban ISA change in Shenyang,followed by land use type and building pattern *** trend of high aggregation was strong in large commercial and residential *** 3D expansion of the city had an influence on its areal expansion.

关键词： Urban impervious surface landscape pattern boosted regression tree linear spectral mixture model driver analysis

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Effect of temperature and moisture on soil organic carbon mineralization of predominantly permafrost peatland in the Great Hing'an Mountains,Northeastern China

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Journal of Environmental Sciences 2010年第7期22卷 1057-1066页

作者： Xianwei Wang Xiuzhen Li yuanman hu Jiujun Lv Ju Sun Zongmei Li Zhifeng Wu Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China Graduate School of Chinese Academy of Sciences Beijing 100039 China Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130012 China

Boreal peatlands represent a large global carbon pool. The relationships between carbon mineralization, soil temperature and moisture in the permafrost peatlands of the Great Hing＇an Mountains, China, were examined. The CO2 emissions were measured during laboratory incubations of samples from four sites under different temperatures （5, 10, 15, and 20℃） and moisture contents （0%, 30%, 60%, 100% water holding capacity （WHC） and completely water saturated）. Total carbon mineralization ranged from 15.51 to 112.92 mg C under the treatments for all sites. Carbon mineralization rates decreased with soil depth, increased with temperature, and reached the highest at 60% WHC at the same temperature. The calculated temperature coefficient （Q10） values ranged from 1.84 to 2.51 with the soil depths and moisture. However, the values were not significantly affected by soil moisture and depth for all sites due to the different peat properties （P 〉 0.05）. We found that the carbon mineralization could be successfully predicted as a two-compartment function with temperature and moisture （R^2 〉 0.96） and total carbon mineralization was significantly affected by temperature and moisture （P 〈 0.05）. Thus, temperature and moisture would play important roles in carbon mineralization of permafrost peatlands in the Great Hing＇an Mountains, indicating that the permafrost peatlands would be sensitive to the environment change, and the permafrost peatlands would be potentially mineralized under future climate change.

关键词： Great Hing'an Mountains permafrost peatland mineralization climate change

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Effects of Forest Roads on Habitat Pattern for Sables in Da Hinggan Mountains, Northeasten China

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Chinese Geographical Science 2014年第5期24卷 587-598页

作者： LI Yuehui WU Wen XIONG Zaiping hu yuanman CHANG Yu XIAO Duning State Key Laboratory of Forest and Soil Ecology Institute of Applied Ecology Chinese Academy of Sciences University of Chinese Academy of Sciences

The anthropogenic managements of forest have created a network of roads resulting in the loss and alternation of habitat. To better understand road′s impact on animal habitats, we assessed the habitat pattern of sables(Martes zibellina), one of rodents within national first-class protected species, when roads are considered in huzhong area in Da Hinggan Mountains, northeastern China. Employing published literatures about behavior ecology, aerial photographs and forest stand maps, we classified the study area into three habitat types including best-suitable, suitable and unsuitable habitats based on sable habitat requirements at the landscape scale including four variables derived from forest source map with attribute database. Results indicated the loss and significant fragmentation of best-suitable habitat and home range habitat when roads, especially 150 m avoidance distance of roads, were considered. The roads reduced and fragmented highly suitable habitats more significantly during earlier development period than the later development period. Additionally, the suitable area percentage increased with increasing distance to roads. This study helped to identify the suitable area for sables and location of sable population. Also, this study suggested the passage construction and road management involving road closure and removal will reduce the fragmentation functionally and benefit the sable population.

关键词： forest road sable habitat pattern buffer analysis Da Hinggan Mountains

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