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Global ecological degradation and rapid economic growth has increased the focus on the sustainable relationship between ecological security and economic development. This paper evaluated and partitioned Guizhou Province's ecological security and economic development, and discussed the population, industrial structure and land use of each zone in 2010 and 2015. An ecological security assessment was performed based on land use. Principal component analysis (PCA) was used to evaluate the level of economic development. Spatially, the ecological security level was high in the south and low in the north of the province, while economic development in central regions was higher than in surrounding areas. The ecological security and wealth gaps were widening. In this study, Guizhou Province was partitioned into the Coordinated Development Zone (CDZ), the Ecological Risk Zone (ERZ), the Economic Poverty Zone (EPZ), and the Dual Pressure Zone (DPZ) based on the ecological security index and economic development index. The characteristics of the population, industrial structure, and land use in the zones showed that generally: (1) Populations became more aggregated in prosperous regions, while ecological security was higher in regions with sparse populations. (2) Regions with a high proportion of primary industry (over 25% in 2010 and over 23% in 2015) lagged economically, while regions with a high proportion of secondary industry (over 35% in 2010 and over 33% in 2015) were prosperous. In poor regions, tertiary industry had less ability to drive economic growth than secondary industry. (3) Nearly half of the communities with below-median values in the ecological security index had a grassland proportion between 20% and 32%, but most of the communities with above-median values in the ecological security index had a grassland proportion of less than 20%. Most communities with better ecological security had a high proportion of forestlands (over 52% in 2010 and over 53% in 2015), and a low proportion of croplands (below 30% in 2010 and below 27% in 2015). The communities with low ecological security showed the opposite pattern. The expansion of mining fields, transportation lands, and settlements on built-up lands was conducive to economic development, but they threatened regional ecological security. Different strategies are proposed for the four zones, based on the analysis. In the CDZ, priority should be given to developing tertiary industry that will improve ecological security. In the ERZ, controls over resource-based industry should be strengthened to implement sustainable industrial development and the focus on ecological restoration and environmental governance should be increased. In the EPZ, the development of the primary, secondary and tertiary industries should be integrated based on tourism, and ecological, environmental and biological resources. In the DPZ, the way of transforming lucid waters and lush mountain into invaluable assets should be explored. The Grain for Green Project should be taken seriously and ecological restoration should be combined with poverty alleviation.
Meiying Sun; Xiuhong Li; Rongjin Yang; Yi Zhang; Le Zhang; Zhenwei Song; Qiang Liu; Dan Zhao. Comprehensive partitions and different strategies based on ecological security and economic development in Guizhou Province, China. Journal of Cleaner Production 2020, 274, 122794 .
AMA StyleMeiying Sun, Xiuhong Li, Rongjin Yang, Yi Zhang, Le Zhang, Zhenwei Song, Qiang Liu, Dan Zhao. Comprehensive partitions and different strategies based on ecological security and economic development in Guizhou Province, China. Journal of Cleaner Production. 2020; 274 ():122794.
Chicago/Turabian StyleMeiying Sun; Xiuhong Li; Rongjin Yang; Yi Zhang; Le Zhang; Zhenwei Song; Qiang Liu; Dan Zhao. 2020. "Comprehensive partitions and different strategies based on ecological security and economic development in Guizhou Province, China." Journal of Cleaner Production 274, no. : 122794.
The effects of forest restoration on ecosystem services and their trade-offs are increasingly discussed by environmental managers and ecologists, but few demonstrations have analyzed ecosystem service trade-offs with a view to informing afforestation choices. Here, we examined how the Grain for Green Program (GGP), an ambitious reforestation program in China, affected ecosystem services. We quantified regulating services and provisioning service in the potential scenarios, which were developed to improve ecosystem services better. The results indicated the GGP drove 14.5% of land-use/land-cover from 2000 to 2015, and all the regulating services increased. Prioritizing reforestations in steep-sloped and riparian farmlands can promote flood mitigation, water purification, and soil retention services by 62.7%, 25.5%, and 216.1% as compared with 2015 levels, respectively, suggesting that the improvements strongly depend on afforestation locations. Driven by the new GGP policy, a high proportion of economic forest increased provisioning service (272.2%), but at the expense of decreases in soil retention (−25.1%), flood mitigation (−11.4%), water purification (−36.6%), and carbon storage (−48.5%). We identified a suitable scenario that would reduce the trade-offs, which associated with afforestation types and their spatial allocation. Identifying priority areas of afforestation types can inform the GGP policy to assure sustainable and broader benefits.
Xiufen Li; Yichen Tian; Tian Gao; Lei Jin; Shuangtian Li; Dan Zhao; Xiao Zheng; Lizhong Yu; Jiaojun Zhu. Trade-Offs Analysis of Ecosystem Services for the Grain for Green Program: Informing Reforestation Decisions in a Mountainous Headwater Region, Northeast China. Sustainability 2020, 12, 4762 .
AMA StyleXiufen Li, Yichen Tian, Tian Gao, Lei Jin, Shuangtian Li, Dan Zhao, Xiao Zheng, Lizhong Yu, Jiaojun Zhu. Trade-Offs Analysis of Ecosystem Services for the Grain for Green Program: Informing Reforestation Decisions in a Mountainous Headwater Region, Northeast China. Sustainability. 2020; 12 (11):4762.
Chicago/Turabian StyleXiufen Li; Yichen Tian; Tian Gao; Lei Jin; Shuangtian Li; Dan Zhao; Xiao Zheng; Lizhong Yu; Jiaojun Zhu. 2020. "Trade-Offs Analysis of Ecosystem Services for the Grain for Green Program: Informing Reforestation Decisions in a Mountainous Headwater Region, Northeast China." Sustainability 12, no. 11: 4762.
This paper proposes a method to classify individual tree species groups based on individual tree segmentation and crown-level spectrum extraction (“crown-based ITC” for abbr.) in a natural mixed forest of Northeast China, and compares with the pixel-based classification and segment summarization results (“pixel-based ITC” for abbr.). Tree species is a basic factor in forest management, and it is traditionally identified by field survey. This paper aims to explore the potential of individual tree classification in a natural, needle-leaved and broadleaved mixed forest. First, individual trees were isolated, and the spectra of individual trees were then extracted. The support vector machine (SVM) and spectrum angle mapper (SAM) classifiers were applied to classify the trees species. The pixel-based classification results from hyperspectral data and LiDAR derived individual tree isolation were compared. The results showed that the crown-based ITC classified broadleaved trees better than pixel-based ITC, while the classes distribution of the crown-based ITC was closer to the survey data. This indicated that crown-based ITC performed better than pixel-based ITC. Crown-based ITC efficiently identified the classes of the dominant and sub-dominant species. Regardless of whether SVM or SAM was used, the identification consistency relative to the field observations for the class of the dominant species was greater than 90%. In contrast, the consistencies of the classes of the sub-dominant species were approximately 60%, and the overall consistency of both the SVM and SAM was greater than 70%.
Dan Zhao; Yong Pang; Lijuan Liu; Zengyuan Li. Individual Tree Classification Using Airborne LiDAR and Hyperspectral Data in a Natural Mixed Forest of Northeast China. Forests 2020, 11, 303 .
AMA StyleDan Zhao, Yong Pang, Lijuan Liu, Zengyuan Li. Individual Tree Classification Using Airborne LiDAR and Hyperspectral Data in a Natural Mixed Forest of Northeast China. Forests. 2020; 11 (3):303.
Chicago/Turabian StyleDan Zhao; Yong Pang; Lijuan Liu; Zengyuan Li. 2020. "Individual Tree Classification Using Airborne LiDAR and Hyperspectral Data in a Natural Mixed Forest of Northeast China." Forests 11, no. 3: 303.
With rapid urbanization in China, the phenomenon of urban sprawl has become prominent and has severely challenged sustainable urbanization and ecological civilization. Aiming to understand the impact of urban sprawl on the urban environment, this study calculates the eco-efficiency of 264 prefecture-level cities in China from 2003 to 2016 by using a super-efficiency data envelopment analysis model. Then, we establish a panel Tobit model and threshold regression model to empirically test the impact of urban sprawl on eco-efficiency and the threshold effect of the urban scale. The results show that urban sprawl hinders the improvement of urban eco-efficiency, especially in Eastern China, but relatively weak or even insignificant effects are observed in Central and Western China. Additionally, a threshold effect of urban sprawl on eco-efficiency can be found. When the city scale is small, urban sprawl seriously hinders the improvement of eco-efficiency. As the city scale gradually expands, the negative effect of urban sprawl on eco-efficiency first decreases, then the restraining effect is gradually strengthened. Our research findings can aid urban development in cities with different scales to reduce the negative effect of urban sprawl on the urban environment.
Qian Zhang; Huaxing Zhang; Dan Zhao; Baodong Cheng; Chang Yu; Yanli Yang. Does Urban Sprawl Inhibit Urban Eco-Efficiency? Empirical Studies of Super-Efficiency and Threshold Regression Models. Sustainability 2019, 11, 5598 .
AMA StyleQian Zhang, Huaxing Zhang, Dan Zhao, Baodong Cheng, Chang Yu, Yanli Yang. Does Urban Sprawl Inhibit Urban Eco-Efficiency? Empirical Studies of Super-Efficiency and Threshold Regression Models. Sustainability. 2019; 11 (20):5598.
Chicago/Turabian StyleQian Zhang; Huaxing Zhang; Dan Zhao; Baodong Cheng; Chang Yu; Yanli Yang. 2019. "Does Urban Sprawl Inhibit Urban Eco-Efficiency? Empirical Studies of Super-Efficiency and Threshold Regression Models." Sustainability 11, no. 20: 5598.
In recent years, climate change, particularly rising carbon dioxide (CO2) concentration and global warming, has attracted much attention around the world. Forest ecosystems still play a crucial role in global carbon (C) fixation. Quantifying forest aboveground biomass (AGB) and its temporal variations is essential for understanding external impacts (e.g., urbanization, environmental change) as well as assessing the potential of forest ecosystems assimilating the atmospheric CO2. In this study, we established regression models for AGB estimation in the Miyun Reservoir region, based on relationships between Landsat-derived variables and ground truth AGB values, which were obtained from both plot measurements and estimations using Light Detection and Ranging (LiDAR) dataset. The models were applied to calibrated Landsat images acquired in 1990, 2000, and 2010 to track the forest AGB temporal variations and the corresponding spatial distributions for each period. The AGB estimations using LiDAR showed high consistency with values based on the plot measurements, while the established models presented an acceptable accuracy. The AGB density in the Miyun Reservoir experienced an overall increase since 1990 and was averaged at 52.20 and 32.12 t ha−1, for stand forest and shrub in 2010, respectively. Total AGB in 2010 was estimated to be 4.5 × 107 t, which increased by 8% when compared with the level in 1990. Our results are in the similar range of AGB density reported by other studies carried out in Northern China. Ecological programs including Three-North Shelter Forest Project and Returning Farming to Forest promoted the forest expansion and development during this period, while local farming activities exerted certain negative effects on the surrounding forest systems. Absolute AGB density values indicated that regions with less external interventions present more consistent biomass accumulation. However, the coarse spatial resolution and 10-year interval of the datasets limited detailed analysis of impacts from urbanization of Beijing City. Future studies incorporating sophisticated ecosystem research methods are expected to uncover the mechanisms and key drivers for the observed variations in the AGB in the Miyun Reservoir region of Beijing, China.
Li Fu; Dan Zhao; Bingfang Wu; Zhihong Xu; Yuan Zeng. Variations in forest aboveground biomass in Miyun Reservoir of Beijing over the past two decades. Journal of Soils and Sediments 2017, 17, 2080 -2090.
AMA StyleLi Fu, Dan Zhao, Bingfang Wu, Zhihong Xu, Yuan Zeng. Variations in forest aboveground biomass in Miyun Reservoir of Beijing over the past two decades. Journal of Soils and Sediments. 2017; 17 (8):2080-2090.
Chicago/Turabian StyleLi Fu; Dan Zhao; Bingfang Wu; Zhihong Xu; Yuan Zeng. 2017. "Variations in forest aboveground biomass in Miyun Reservoir of Beijing over the past two decades." Journal of Soils and Sediments 17, no. 8: 2080-2090.
Grassland as a distinct landscape type sustains biological and cultural diversity. However, its use at an unprecedentedly high intensity has had a disastrous impact on grassland ecosystems, with degeneration occurring nationwide. Traditional management policy, drafted according to the stocking rate from livestock statistics and/or in situ assessment, seems to have played no role in alleviating this trend. A major cause is the failure of decision making to consider spatial heterogeneity in the impact of grazing on grassland. To address this issue, high temporal resolution moderate-resolution imaging spectroradiometer data were used to develop a new indicator, named the grazing intensity index (GII), for quantifying grazing intensity (GI). The new index was compared with two traditional approaches and the results demonstrated that GII could substitute for both of them to quantify GI.
Po Liu; Fei Li; Yongfei Bai; Hongwei Wan; Jiajia Zheng; Juhua Luo; Dan Zhao. Quantifying Grazing Intensity in China Using High Temporal Resolution MODIS Data. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing 2016, 10, 515 -523.
AMA StylePo Liu, Fei Li, Yongfei Bai, Hongwei Wan, Jiajia Zheng, Juhua Luo, Dan Zhao. Quantifying Grazing Intensity in China Using High Temporal Resolution MODIS Data. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. 2016; 10 (2):515-523.
Chicago/Turabian StylePo Liu; Fei Li; Yongfei Bai; Hongwei Wan; Jiajia Zheng; Juhua Luo; Dan Zhao. 2016. "Quantifying Grazing Intensity in China Using High Temporal Resolution MODIS Data." IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing 10, no. 2: 515-523.
Remote sensing provides a consistent form of observation for biodiversity monitoring across space and time. However, the regional mapping of forest species diversity is still difficult because of the complexity of species distribution and overlapping tree crowns. A new method called “spectranomics” that maps forest species richness based on leaf chemical and spectroscopic traits using imaging spectroscopy was developed by Asner and Martin. In this paper, we use this method to detect the relationships among the spectral, biochemical and taxonomic diversity of tree species, based on 20 dominant canopy species collected in a subtropical forest study site in China. Eight biochemical components (chlorophyll, carotenoid, specific leaf area, equivalent water thickness, nitrogen, phosphorus, cellulose and lignin) are quantified by spectral signatures (R2 = 0.57–0.85, p < 0.01). We also find that the simulated maximum species number based on the eight optimal biochemical components is approximately 15, which is suitable for most 30 m × 30 m forest sites within this study area. This research may support future work on regional species diversity mapping using airborne imaging spectroscopy.
Yujin Zhao; Yuan Zeng; Dan Zhao; Bingfang Wu; Qianjun Zhao. The Optimal Leaf Biochemical Selection for Mapping Species Diversity Based on Imaging Spectroscopy. Remote Sensing 2016, 8, 216 .
AMA StyleYujin Zhao, Yuan Zeng, Dan Zhao, Bingfang Wu, Qianjun Zhao. The Optimal Leaf Biochemical Selection for Mapping Species Diversity Based on Imaging Spectroscopy. Remote Sensing. 2016; 8 (3):216.
Chicago/Turabian StyleYujin Zhao; Yuan Zeng; Dan Zhao; Bingfang Wu; Qianjun Zhao. 2016. "The Optimal Leaf Biochemical Selection for Mapping Species Diversity Based on Imaging Spectroscopy." Remote Sensing 8, no. 3: 216.
Topography affects forest canopy height retrieval based on airborne Light Detection and Ranging (LiDAR) data a lot. This paper proposes a method for correcting deviations caused by topography based on individual tree crown segmentation. The point cloud of an individual tree was extracted according to crown boundaries of isolated individual trees from digital orthophoto maps (DOMs). Normalized canopy height was calculated by subtracting the elevation of centres of gravity from the elevation of point cloud. First, individual tree crown boundaries are obtained by carrying out segmentation on the DOM. Second, point clouds of the individual trees are extracted based on the boundaries. Third, precise DEM is derived from the point cloud which is classified by a multi-scale curvature classification algorithm. Finally, a height weighted correction method is applied to correct the topological effects. The method is applied to LiDAR data acquired in South China, and its effectiveness is tested using 41 field survey plots. The results show that the terrain impacts the canopy height of individual trees in that the downslope side of the tree trunk is elevated and the upslope side is depressed. This further affects the extraction of the location and crown of individual trees. A strong correlation was detected between the slope gradient and the proportions of returns with height differences more than 0.3, 0.5 and 0.8 m in the total returns, with coefficient of determination R2 of 0.83, 0.76, and 0.60 (n = 41), respectively.
Zhugeng Duan; Dan Zhao; Yuan Zeng; Yujin Zhao; Bingfang Wu; Jianjun Zhu. Assessing and Correcting Topographic Effects on Forest Canopy Height Retrieval Using Airborne LiDAR Data. Sensors 2015, 15, 12133 -12155.
AMA StyleZhugeng Duan, Dan Zhao, Yuan Zeng, Yujin Zhao, Bingfang Wu, Jianjun Zhu. Assessing and Correcting Topographic Effects on Forest Canopy Height Retrieval Using Airborne LiDAR Data. Sensors. 2015; 15 (6):12133-12155.
Chicago/Turabian StyleZhugeng Duan; Dan Zhao; Yuan Zeng; Yujin Zhao; Bingfang Wu; Jianjun Zhu. 2015. "Assessing and Correcting Topographic Effects on Forest Canopy Height Retrieval Using Airborne LiDAR Data." Sensors 15, no. 6: 12133-12155.