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Trunk volume estimation of irregular shaped Populus euphratica riparian forest using TLS point cloud data and multivariate prediction models

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Forest Ecosystems 2023年第1期10卷 1-11页

作者： Asadilla Yusup Umut Halik Maierdang Keyimu Tayierjiang Aishan Abdulla Abliz Babierjiang Dilixiati Jianxin Wei College of Ecology and Environment Ministry of Education Key Laboratory of Oasis EcologyXinjiang UniversityUrumqi830046China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of ScienceUrumqi830011China Cele National station of Observation and Research for Desert-grassland Ecosystems Cele848300China College of Tourism Key Laboratory of Sustainable Development of Xinjiang's Historical and Cultural TourismXinjiang UniversityUrumqi830046China xinjiang Laser Radar Engineering Technology Center Urumqi830002China

Background: Trunk volume(Vt) is an essential parameter for estimating forest stand volume, biomass, and carbon sequestration potential. As the dominant tree species in desert riparian forests, Euphrates poplar(Populus euphratica) has a high proportion of irregularly shaped tree trunks along the Tarim River, NW China, where the habitat is very fragile owing to long-term water stress. This causes uncertainty in estimation accuracy as well as technical challenges for forest surveys. Our study aimed to acquire P. euphratica Vtusing terrestrial laser scanning(TLS) and to establish a species-specific Vtprediction model.Methods: A total of 240 individual trees were measured by TLS multiple-station in 12 sampling plots in three sections along the lower reaches of the Tarim River. Vtwas calculated by a definite integration method using trunk diameters(Di) at every 0.1-m tree height obtained from TLS, and all data were split randomly into two sets:70% of data were used to estimate the model parameter calibration, and the remaining 30% were used for model validation. Sixteen widely used candidate tree Vtestimation models were fitted to the TLS-measured Vtand tree structural parameter data, including tree height(H), diameter at breast height(DBH), and basal diameter(BD). All model performances were evaluated and compared by the statistical parameters of determination coefficient(R^(2)),root mean square error(RMSE), Bayesian information criterion(BIC), mean prediction error(ME), mean absolute error(MAE), and modeling efficiency(EF), and accordingly the best model was selected.Results: TLS point cloud reflection intensity(RI) has advantageous in the extraction of data from irregular tree trunk structures. The P. euphratica tree Vtvalues showed obvious differences at the same tree height(H). There was no significant correlation between Vtand H(R^(2)=0.11, P < 0.01), which reflected the irregularity of P. euphratica trunk shape in the study area. Among all the models, model(14): Vt=0.909DBH1.184H0.487BD0.836(R^(2)=0.97, RMSE=0.1

关键词： Populus euphratica Trunk volume Terrestrial laser scanning(TLS) Reflection intensity Tarim river

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How precipitation and grazing influence the ecological functions of drought-prone grasslands on the northern slopes of the Tianshan Mountains, China?

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Journal of Arid Land 2021年第1期13卷 88-97页

作者： HUANG Xiaotao LUO Geping CHEN Chunbo PENG Jian ZHANG Chujie ZHOU Huakun YAO Buqing MA Zhen XI Xiaoyan Qinghai Provincial Key Laboratory of Restoration Ecology for Cold Regions Northwest Institute of Plateau BiologyChinese Academy of SciencesXining 810008China Key Laboratory of Adaptation and Evolution of Plateau Biota Chinese Academy of SciencesXining 810008China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China xinjiang grassland technical popularization station Urumqi 830049China Qinghai Environmental Sciences Research and Design Institute Co.Ltd. Xining 810007China

Drought-prone grasslands provide a critical resource for the millions of people who are dependent on livestock for food security.However,this ecosystem is potentially vulnerable to climate change(e.g.,precipitation)and human activity(e.g.,grazing).Despite this,the influences of precipitation and grazing on ecological functions of drought-prone grasslands in the Tianshan Mountains remain relatively unexplored.Therefore,we conducted a systematic field investigation and a clipping experiment(simulating different intensities of grazing)in a drought-prone grassland on the northern slopes of the Tianshan Mountains in China to examine the influences of precipitation and grazing on aboveground biomass(AGB),soil volumetric water content(SVWC),and precipitation use efficiency(PUE)during the period of 2014–2017.We obtained the meteorological and SVWC data using an HL20 Bowen ratio system and a PR2 soil profile hydrometer,respectively.We found that AGB was clearly affected by both the amount and seasonal pattern of precipitation,and that PUE may be relatively low in years with either low or excessive precipitation.The PUE values were generally higher in the rapid growing season(April–July)than in the entire growing season(April–October).Overall,moderate grazing can promote plant growth under water stress conditions.The SVWC value was higher in the clipped plots than in the unclipped plots in the rapid growing season(April–July),but it was lower in the clipped plots than in the unclipped plots in the slow growing season(August–October).Our findings can enhance the understanding of the ecological effects of precipitation and grazing in drought-prone grasslands and provide data that will support the effective local grassland management.

关键词： climate change human activity aboveground biomass precipitation use efficiency soil volumetric water content water stress

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Climate change, water resources and sustainable development in the arid and semi-arid lands of Central Asia in the past 30 years

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Journal of Arid Land 2019年第1期11卷 1-14页

作者： YU Yang PI Yuanyue YU Xiang TA Zhijie SUN Lingxiao Markus DISSE ZENG Fanjiang LI Yaoming CHEN Xi YU Ruide xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Research Center for Ecology and Environment of Central Asia Chinese Academy of Sciences Cele National station of Observation and Research for Desert-grassland Ecosystem University of Chinese Academy of Sciences Chinese Academy of Forestry State Key Laboratory of Desert and Oasis Ecology Chinese Academy of Sciences Chair of Hydrology and River Basin Management Technical University of Munich School of Environment and Material Science Yantai University

The countries of Central Asia are collectively known as the five "-stans": Uzbekistan, Kyrgyzstan, Turkmenistan, Tajikistan and Kazakhstan. In recent times, the Central Asian region has been affected by the shrinkage of the Aral Sea, widespread desertification, soil salinization, biodiversity loss, frequent sand storms, and many other ecological disasters. This paper is a review article based upon the collection, identification and collation of previous studies of environmental changes and regional developments in Central Asia in the past 30 years. Most recent studies have reached a consensus that the temperature rise in Central Asia is occurring faster than the global average. This warming trend will not only result in a higher evaporation in the basin oases, but also to a significant retreat of glaciers in the mountainous areas. Water is the key to sustainable development in the arid and semi-arid regions in Central Asia. The uneven distribution, over consumption, and pollution of water resources in Central Asia have caused severe water supply problems, which have been affecting regional harmony and development for the past 30 years. The widespread and significant land use changes in the 1990 s could be used to improve our understanding of natural variability and human interaction in the region. There has been a positive trend of trans-border cooperation among the Central Asian countries in recent years. International attention has grown and research projects have been initiated to provide water and ecosystem protection in Central Asia. However, the agreements that have been reached might not be able to deliver practical action in time to prevent severe ecological disasters. Water management should be based on hydrographic borders and ministries should be able to make timely decisions without political intervention. Fully integrated management of water resources, land use and industrial development is essential in Central Asia. The ecological crisis should provide sufficient motivation to reach a consensus on u

关键词： Central Asia climate change water resources arid and semi-arid lands land use changes sustainable development socio-economic development

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Study on Ecological Landscape Pattern Change of Desert Sewage Discharge Area in Desert-Oasis Ecotone on the Southern Edge of Junggar Basin,xinjiang

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气象与环境研究：英文版 2021年第6期12卷 7-15,23页

作者： Xin HAN Li CHEN Shaotang LIU xinjiang Academy of Environmental Protection Science Urumqi 830011China xinjiang Key Laboratory for Environmental Pollution Monitoring and Risk Warning Urumqi 830011China xinjiang Engineering Technology Research Center for Cleaner Production Urumqi 830011China Junggar Desert-Oasis Ecotone station for Scientific Observation and Research of National Environmental Protection Urumqi 830011China

In order to understand the change characteristics of ecological landscape pattern of desert sewage discharge area in the desert-oasis ecotone on the southern edge of Junggar Basin,xinjiang,based on the remote sensing images of 13 scenes GF1 and GF2 from 2013 to 2019,through image preprocessing,classification interpretation,GIS spatial analysis and landscape pattern index,the conclusions were as follows.From 2013 to 2019,the landscape area of sparse shrub forest land,grassland and saline alkali land increased,while the area of sandy bare land and pond surface increased.The mutual transformation among various types of landscapes was more active,among which the mutual transfer between sandy bare land and sparse shrub forest land was the most frequent.Various landscape dynamics changed significantly with time.All kinds of landscapes and the overall landscape showed the trend of fragmentation,discretization and complexity,and the overall landscape showed the trend of balanced distribution.The above results hoped to provide basic data and technical basis for eco-environmental protection,restoration and treatmen on the southern edge of Junggar Basin,and fill the current research gap.

关键词： Landscape pattern index Desert-oasis ecotone Desert sewage discharge

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中亚气候变化:中德合作研究成果

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Science Bulletin 2020年第9期65卷 689-692,M0003页

作者：于洋陈曦 Markus Disse Bernd Cyffka 雷加强张海燕 Andreas Brieden Martin Welp 吉力力·阿不都外力李耀明曾凡江桂东伟 Niels Thevs 他志杰高鑫皮原月于翔孙凌霄于瑞德 xinjiang Institute of Ecology and Geography Chinese Academy of SciencesUrumqi 830011China Research Center for Ecology and Environment of Central Asia Chinese Academy of SciencesUrumqi 830011China Cele National station of Observation and Research for Desert-grassland Ecosystem Cele 848300China State Key Laboratory of Desert and Oasis Ecology Chinese Academy of SciencesUrumqi 830011China Chair of Hydrology and River Basin Management Technical University of MunichMunich 80333Germany Applied Physical Geography Catholic University of Eichstaett-IngolstadtEichstaett 85071Germany Chair of Statistics and Risk Management Universitaet der Bundeswehr MuenchenNeubiberg 85577Germany Faculty of Forest and Environment Eberswalde University for Sustainable DevelopmentEberswalde 16225Germany Institute of Botany and Landscape Ecology University of GreifswaldGreifswald 17487Germany Central Asia Branch Office World Agroforestry CenterBishkek 720001Kyrgyzstan University of Chinese Academy of Sciences Beijing 100049China Chinese Academy of Forestry Beijing 100091China School of Environmental and Material Engineering Yantai UniversityYantai 264005China

Central Asia(CA)occupies the hinterland of the Eurasian continent,containing the countries of Uzbekistan,Kyrgyzstan,Turkmenistan,Tajikistan,and Kazakhstan[1,2].Being isolated by the Pamir Mountains in Tajikistan,the T... 详细信息

关键词：气候变化 Mountains Eurasian

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