Greening and Browning of the Hexi Corridor in Northwest China: Spatial Patterns and Responses to Climatic Variability and Anthropogenic Drivers

The arid region of northwest China provides a unique terrestrial ecosystem to identify the response of vegetation activities to natural and anthropogenic changes. To reveal the influences of climate and anthropogenic factors on vegetation, the Normalized Difference Vegetation Index (NDVI), climate data, and land use and land cover change (LUCC) maps were used for this study. We analyzed the spatiotemporal change of NDVI during 2000–2015. A partial correlation analysis suggested that the contribution of precipitation (PRE) and temperature (TEM) on 95.43% of observed greening trends was 47% and 20%, respectively. The response of NDVI in the eastern section of the Qilian Mountains (ESQM) and the western section of the Qilian Mountains (WSQM) to PRE and TEM showed opposite trends. The multiple linear regressions used to quantify the contribution of anthropogenic activity on the NDVI trend indicated that the ESQM and oasis areas were mainly affected by anthropogenic activities (26%). The observed browning trend in the ESQM was attributed to excessive consumption of natural resources. A buffer analysis and piecewise regression methods were further applied to explore the influence of urbanization on NDVI and its change rate. The study demonstrated that urbanization destroys the vegetation cover within the developed city areas and extends about 4 km beyond the perimeter of urban areas and the NDVI of buffer cities (counties) in the range of 0–4 km (0–3 km) increased significantly. In the range of 5–15 (4–10) km (except for Jiayuguan), climate factors were the major drivers of a slight downtrend in the NDVI. The relationship of land use change and NDVI trends showed that construction land, urban settlement, and farmland expanded sharply by 171.43%, 60%, and 10.41%, respectively. It indicated that the rapid process of urbanization and coordinated urban-rural development shrunk ecosystem services.

[1]  Jon Holmgren,et al.  Snow-Shrub Interactions in Arctic Tundra: A Hypothesis with Climatic Implications , 2001 .

[2]  Bo Qu,et al.  Spatio-Temporal Changes in Vegetation Activity and Its Driving Factors during the Growing Season in China from 1982 to 2011 , 2015, Remote. Sens..

[3]  Jacob Cohen,et al.  Applied multiple regression/correlation analysis for the behavioral sciences , 1979 .

[4]  Stephen Polasky,et al.  Projected land-use change impacts on ecosystem services in the United States , 2014, Proceedings of the National Academy of Sciences.

[5]  Shaohong Wu,et al.  Interannual Variations in Growing-Season NDVI and Its Correlation with Climate Variables in the Southwestern Karst Region of China , 2015, Remote. Sens..

[6]  Nicholas C. Coops,et al.  Changes in vegetation photosynthetic activity trends across the Asia-Pacific region over the last three decades , 2014 .

[7]  Bruce C. Forbes,et al.  Land use and land cover change in Arctic Russia: ecological and social implications of industrial development. , 2011 .

[8]  Jacob Heilmann-Clausen,et al.  Forest biodiversity gradients and the human impact in Annapurna Conservation Area, Nepal , 2009, Biodiversity and Conservation.

[9]  Steven F. Oberbauer,et al.  Plot-scale evidence of tundra vegetation change and links to recent summer warming. , 2012 .

[10]  B. Forbes,et al.  Anthropogenic Disturbance and Patch Dynamics in Circumpolar Arctic Ecosystems , 2001 .

[11]  P. Campanello,et al.  High NDVI and Potential Canopy Photosynthesis of South American Subtropical Forests despite Seasonal Changes in Leaf Area Index and Air Temperature , 2014 .

[12]  Zhengyi Yao,et al.  Alpine grassland degradation in the Qilian Mountains, China — A case study in Damaying Grassland , 2016 .

[13]  I. Esau,et al.  Trends in normalized difference vegetation index (NDVI) associated withurban development in northern West Siberia , 2016 .

[14]  Jianhui Huang,et al.  Distinguishing between human-induced and climate-driven vegetation changes: a critical application of RESTREND in inner Mongolia , 2012, Landscape Ecology.

[15]  J. Comiso,et al.  Relationship between satellite-derived land surface temperatures, arctic vegetation types, and NDVI , 2008 .

[16]  Shengjun Wu,et al.  NDVI indicated long-term interannual changes in vegetation activities and their responses to climatic and anthropogenic factors in the Three Gorges Reservoir Region, China. , 2017, The Science of the total environment.

[17]  G. Midgley,et al.  Photosynthetic and gas exchange characteristics of dominant woody plants on a moisture gradient in an African savanna , 2004 .

[18]  T. McVicar,et al.  Impact of CO2 fertilization on maximum foliage cover across the globe's warm, arid environments , 2013 .

[19]  Youjia Liang,et al.  Modeling urban growth in the middle basin of the Heihe River, northwest China , 2014, Landscape Ecology.

[20]  Bin Zhao,et al.  Impact of Climate Change on Vegetation Growth in Arid Northwest of China from 1982 to 2011 , 2016, Remote. Sens..

[21]  Zhenghui Xie,et al.  Observational Quantification of Climatic and Human Influences on Vegetation Greening in China , 2017, Remote. Sens..

[22]  Yansui Liu,et al.  Dynamic analysis of ecological environment combined with land cover and NDVI changes and implications for sustainable urban–rural development: The case of Mu Us Sandy Land, China , 2017 .

[23]  Dawn M. Kaufman,et al.  Changes in grassland ecosystem function due to extreme rainfall events: implications for responses to climate change , 2008 .

[24]  E. Lambin,et al.  Dynamics of Land-Use and Land-Cover Change in Tropical Regions , 2003 .

[25]  E. Kang,et al.  Recent and Future Climate Change in Northwest China , 2007 .

[26]  Niti B. Mishra,et al.  Greening and browning of the Himalaya: Spatial patterns and the role of climatic change and human drivers. , 2017, The Science of the total environment.

[27]  Compton J. Tucker,et al.  Recent Declines in Warming and Vegetation Greening Trends over Pan-Arctic Tundra , 2013, Remote. Sens..

[28]  S. Garrigues,et al.  Multiscale geostatistical analysis of AVHRR, SPOT-VGT, and MODIS global NDVI products , 2008 .

[29]  J. Canadell,et al.  Greening of the Earth and its drivers , 2016 .

[30]  Gang Bao,et al.  NDVI-Based Long-Term Vegetation Dynamics and Its Response to Climatic Change in the Mongolian Plateau , 2014, Remote. Sens..

[31]  M. Steinbach,et al.  Terrestrial vegetation dynamics and global climate controls , 2008 .

[32]  Rasmus Fensholt,et al.  Greenness in semi-arid areas across the globe 1981–2007 — an Earth Observing Satellite based analysis of trends and drivers , 2012 .

[33]  A. Strahler,et al.  The footprint of urban climates on vegetation phenology , 2004 .

[34]  C. Tucker,et al.  Climate-Driven Increases in Global Terrestrial Net Primary Production from 1982 to 1999 , 2003, Science.

[35]  H. Prins,et al.  Factors influencing the distribution of large mammals within a protected central African forest , 2005, Oryx.

[36]  A. Braimoh.  Random and systematic land-cover transitions in northern Ghana , 2006 .

[37]  P. Su,et al.  Ecological effects of desertification control and desertified land reclamation in an oasis–desert ecotone in an arid region: A case study in Hexi Corridor, northwest China , 2007 .

[38]  G. Luck,et al.  The relationships between net primary productivity, human population density and species conservation , 2007 .

[39]  Jikun Huang,et al.  The impact of climate change on China's agriculture. , 2009 .

[40]  P. Dearden,et al.  Fragmentation and wildlife in montane evergreen forests, northern Thailand , 2002 .

[41]  P. Ciais,et al.  The impacts of climate change on water resources and agriculture in China , 2010, Nature.

[42]  W. Oechel,et al.  Environmental controls over carbon dioxide and water vapor exchange of terrestrial vegetation , 2002 .

[43]  Shuangshuang Li,et al.  Changes in Growing Season Vegetation and Their Associated Driving Forces in China during 2001-2012 , 2015, Remote. Sens..

[44]  Ping Wang,et al.  Vegetation responses to integrated water management in the Ejina basin, northwest China , 2011 .

[45]  G. Roderick,et al.  Remote sensing captures varying temporal patterns of vegetation between human-altered and natural landscapes , 2015, PeerJ.

[46]  Martin Brandt,et al.  Revisiting the coupling between NDVI trends and cropland changes in the Sahel drylands: A case study in western Niger , 2017 .

[47]  L. Curran,et al.  Village size and forest disturbance in Bhadra Wildlife Sanctuary, Western Ghats, India , 2006 .

[48]  Shuangcheng Li,et al.  Spatial pattern of non-stationarity and scale-dependent relationships between NDVI and climatic factors—A case study in Qinghai-Tibet Plateau, China , 2012 .

[49]  R. Fensholt,et al.  Evaluating temporal consistency of long-term global NDVI datasets for trend analysis , 2015 .

[50]  Zhi Li,et al.  Progress and prospects of climate change impacts on hydrology in the arid region of northwest China. , 2015, Environmental Research.

[51]  B. McConkey,et al.  Monitoring and modeling spatial and temporal patterns of grassland dynamics using time-series MODIS NDVI with climate and stocking data , 2013 .

[52]  N. Dessay,et al.  Can a 25-year trend in Soudano-Sahelian vegetation dynamics be interpreted in terms of land use change? A remote sensing approach , 2011 .

[53]  Bin Xu,et al.  Remote sensing monitoring of grassland vegetation growth in the Beijing-Tianjin sandstorm source project area from 2000 to 2010 , 2015 .

[54]  Massimo Menenti,et al.  Phenological response of vegetation to upstream river flow in the Heihe Rive basin by time series analysis of MODIS data , 2011 .

[55]  Daniel S. Chapman,et al.  Impacts of resource extraction on forest structure and diversity in Bardia National Park, Nepal , 2010 .

[56]  Hongyan Cai,et al.  Is Forest Restoration in the Southwest China Karst Promoted Mainly by Climate Change or Human-Induced Factors? , 2014, Remote. Sens..

[57]  Alpine sparsely vegetated areas in the eastern Qilian Mountains shrank with climate warming in the past 30 years , 2018 .

[58]  Shuguang Liu,et al.  Spatiotemporal trends of terrestrial vegetation activity along the urban development intensity gradient in China's 32 major cities. , 2014, The Science of the total environment.

[59]  Ranga B. Myneni,et al.  A two-fold increase of carbon cycle sensitivity to tropical temperature variations , 2014, Nature.

[60]  Yili Zhang,et al.  NDVI-based vegetation changes and their responses to climate change from 1982 to 2011: A case study in the Koshi River Basin in the middle Himalayas , 2013 .

[61]  B. Poulter,et al.  Detection and attribution of vegetation greening trend in China over the last 30 years , 2015, Global change biology.

[62]  S. Sterling,et al.  Human Appropriation of Photosynthesis Products , 2001, Science.

[63]  Ranga B. Myneni,et al.  Recent change of vegetation growth trend in China , 2011 .

[64]  L. Telesca,et al.  Discriminating dynamical patterns in burned and unburned vegetational covers by using SPOT‐VGT NDVI data , 2005 .

[65]  Xiangzheng Deng,et al.  Land-use/land-cover change and ecosystem service provision in China. , 2017, The Science of the total environment.

[66]  Shuguang Liu,et al.  Remotely sensed assessment of urbanization effects on vegetation phenology in China's 32 major cities. , 2016 .

[67]  S. Goetz,et al.  Satellite-observed photosynthetic trends across boreal North America associated with climate and fire disturbance. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[68]  Wei Zhou,et al.  Quantitative assessment of the individual contribution of climate and human factors to desertification in northwest China using net primary productivity as an indicator , 2015 .

[69]  Conghe Song,et al.  Reanalysis of global terrestrial vegetation trends from MODIS products: Browning or greening? , 2017 .

[70]  G. Henebry,et al.  Using multiple remote sensing perspectives to identify and attribute land surface dynamics in Central Asia 2001–2013 , 2015 .

[71]  M. Lesperance,et al.  PIECEWISE REGRESSION: A TOOL FOR IDENTIFYING ECOLOGICAL THRESHOLDS , 2003 .

[72]  P. Ciais,et al.  Variations in satellite‐derived phenology in China's temperate vegetation , 2006 .

[73]  C J Tucker,et al.  Drier summers cancel out the CO2 uptake enhancement induced by warmer springs. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[74]  Ling Tong,et al.  Analysis of impacts of climate variability and human activity on streamflow for a river basin in arid region of northwest China , 2008 .

[75]  Yaoming Ma,et al.  Assessment of vegetation dynamics and their response to variations in precipitation and temperature in the Tibetan Plateau , 2010 .