Research on the Territorial Ecological Restoration of Counties for the Increase of Carbon Sinks—A Case Study of Wensu County, Xinjiang Uygur Autonomous Region, China
Qingwen ZHANG, Ying YANG, Yi YUAN, Jingyi HAN, Dihua LI()
College of Architecture and Landscape, Peking University, Beijing 100080, China
As global climate continues to change, it is pressing to integrate the carbon peaking and carbon neutrality goals into territorial spatial planning. While little existing ecological restoration research focuses on counties in western China, particularly arid areas of northwest China, this research took Wensu County of the Xinjiang Uygur Autonomous Region in China as the study case, evaluated the carbon sequestration capacity and carbon storage of the current carbon sinks, identified the spatial pattern of carbon sinks, and proposed the territorial ecological restoration approaches to increasing carbon sinks. The evaluation results show that the importance level of carbon sinks varies significantly across geographical environments of the county, where one primary carbon sink, two secondary carbon sinks, and potential carbon sinks with a total area of 2259.81 km2 were identified. This research extracted eight typical land use patterns based on current land use and proposed ecological restoration strategies accordingly. This research shows a way to integrate carbon peaking and carbon neutrality goals in territorial spatial planning, which is instrumental for carbon sink management in the arid areas of northwest China and provides a referable paradigm for regions with similar geographical conditions.
● Focuses on ecological restoration in a county in the arid areas of northwest China, aiming for carbon sink increase
● Evaluates the carbon sequestration and storage patterns of current carbon sinks in the study area and identifies the spatial pattern of carbon sink importance level
● Extracts typical land use patterns based on current land use and proposes ecological restoration strategies accordingly
. [J]. Landscape Architecture Frontiers, 2024, 12(3): 10-26.
Qingwen ZHANG, Ying YANG, Yi YUAN, Jingyi HAN, Dihua LI. Research on the Territorial Ecological Restoration of Counties for the Increase of Carbon Sinks—A Case Study of Wensu County, Xinjiang Uygur Autonomous Region, China. Landsc. Archit. Front., 2024, 12(3): 10-26.
Temperate bunch short grass and dwarf subshrub desert steppe
2.1
4.57
9.597
Meadow
Temperate grass and forb halophyte meadow
3.7
24.07
89.059
Temperate grass, sedge, and forb marsh meadow
3.9
0.07
0.273
Alpine Kobresia and forb meadow
1.8
3.50
6.300
Alpine vegetation
Alpine cushion-like vegetation
3.3
0.65
2.145
Alpine talus vegetation
3.3
18.20
60.060
Cultivated vegetation
Two-year triple cropping or one-year double cropping dry farming and deciduous orchard
5.7
11.46
65.322
Non-vegetation area
0.0
21.04
0.000
Total
—
142.15
361.013
Tab.2
Fig.3
Category
Description
Primary carbon sink
· Continuous carbon sinks that are mostly rated as "very high" and "high" level of importance, critical to maintaining and increasing carbon sinks
· They are mostly covered by natural vegetation with little human intervention, featuring a healthy ecosystem and abundant natural endowments
· Ecological protection should be prioritized
Secondary carbon sink
· Continuous carbon sinks that are rated as "high" level of importance
· They are mainly covered by cultivated vegetation
· It requires site-specific ecological protection and restoration approaches
Potential carbon sink
· Areas between the primary and secondary carbon sinks, rated as "moderate, " "low, " and "very low" level of importance
· They are mainly covered by natural vegetation, surrounded by large areas of unused land such as Gobi desert and bare rock or gravel; the vegetation is in fair condition, easily to be disturbed and generate carbon emissions
· Key areas to increase carbon sinks with gradual ecological restoration while avoiding large amount of carbon emissions from disturbances
Tab.3
Resistance factor
Information entropy (e)
Difference coefficient (d)
Weight (w)
Slope
0.8898
0.1102
28.8111%
Elevation
0.8758
0.1242
32.4634%
Land use
0.9680
0.0320
8.3713%
Annual accumulated temperature
0.9101
0.0899
23.4966%
Annual precipitation
0.9881
0.0119
3.1203%
Population density
0.9857
0.0143
3.7373%
Tab.4
Resistance factor
Level
Value
Slope (°)
< 20
1
[20, 40)
3
[40, 60)
5
[60, 80)
7
≥ 80
9
Elevation (m)
< 2,000
1
[2,000, 3,000)
2
[3,000, 4,000)
4
[4,000, 5,000)
6
[5,000, 6,000)
8
≥ 6,000
10
Land use
Forest
1
Grassland
1
Farmland
3
Water area
5
Urban land, rural settlement, and other development land
10
Unused land
5
Annual accumulated temperature (℃)
≥ 4,000
1
[3,000, 4,000)
3
[2,000, 3,000)
5
[1,000, 2,000)
7
< 1,000
9
Annual precipitation (mm)
≥ 600
1
[450, 600)
3
[300, 450)
5
[150, 300)
7
< 150
9
Population density (people per square kilometer)
< 1, 000
1
[1000, 2000)
3
[2000, 3000)
5
[3000, 4000)
7
≥ 4,000
9
Tab.5
Fig.4
Fig.5
Land use type
Land use subtype
Management approaches
Forest
Forest land, shrub land, open forest land, other forest land
Afforestation and reforestation, converting farmland to forest, natural forest protection, forest tending, naturalization of man-made forests, mixed forest plantation, agroforestry
Grassland
High coverage grassland, medium coverage grassland, low coverage grassland
Sandy land, Gobi desert, saline-alkali land, bare soil, bare rock or gravel
Soil remediation and maintenance, planting saline-tolerant and sand-fixing species, introducing new biotechnology to cultivate species (trees, grasses, or microorganisms) that can adapt to local conditions and efficiently sequestrate carbon
Tab.6
Fig.6
Fig.7
Fig.8
Fig.9
Fig.10
Fig.11
Fig.12
Land use subtype
Area (km2)
Percentage
Total area (km2)
Dry land
2.88
0.27%
1,083.87
Forest land
41.29
3.81%
Shrub land
0.12
0.01%
Open forest land
36.54
3.37%
High coverage grassland
526.79
48.60%
Medium coverage grassland
124.45
11.48%
Low coverage grassland
344.26
31.76%
River and canal
5.70
0.53%
Floodplain
1.84
0.17%
Tab.7
Land use subtype
Area (km2)
Percentage
Total area (km2)
Paddy land
4.65
0.24%
1,899.69
Dry land
1,645.65
86.63%
Forest land
0.12
0.01%
Other forest land
51.65
2.72%
High coverage grassland
15.16
0.80%
Medium coverage grassland
12.21
0.64%
Low coverage grassland
78.79
4.15%
River and canal
8.18
0.43%
Reservoir
0.57
0.03%
Floodplain
13.55
0.71%
Urban land
2.21
0.12%
Rural settlement
65.66
3.46%
Gobi desert
0.31
0.01%
Bare soil
0.98
0.05%
Tab.8
Land use subtype
Area (km2)
Percentage
Total area (km2)
Dry land
16.13
0.71%
2,259.81
High coverage grassland
5.11
0.23%
Medium coverage grassland
146.40
6.48%
Low coverage grassland
1,158.73
51.28%
Gobi desert
330.84
14.64%
Bare soil
41.88
1.85%
Bare rock or gravel
560.72
24.81%
Tab.9
Fig.13
Category
Spatial pattern of land use
Characteristic
Ecological restoration strategy
Approach
Primary carbon sink
Forest–grassland
Continuous grassland scattered with forest patches
High-carbon reinforcement
Conserving existing carbon pools, restoring soil fertility, and increasing grassland carbon sink and storage by growing mixed forest on abandoned grasslands, forestation and reforestation, grazing intensity control, and natural grassland enclosure
Secondary carbon sink
Gobi–farmland–grassland
Continuous Gobi desert with floodplain, grassland, and farmland along the borders
Carbon conservation restoration
Increasing the above-ground biomass, restoring soil fertility, conserving existing soil carbon pools, and enhancing grassland carbon sink via boundary restoration, floodplain ecological conservation, degraded grassland reseeding and maintenance, and converting farmland to grassland
Farmland–forest land–rural settlement
Continuous farmland with scattered rural settlements and plantations
Low-carbon development
Recycling the agricultural, forest, and residential resources, reducing resource consumption, and enhancing farmland carbon sequestration and storage (soil and vegetation) via conservation tillage, agroforestry, and agricultural waste recycling
Potential carbon sink
Bare rock or gravel–grassland
Bare rock or gravel areas with belts of low-coverage grassland
Carbon conservation expansion
Maintaining natural succession, restoring soil fertility, and thus enhancing grassland carbon sink by soil mediation and maintenance of saline-alkali land, planting saline-tolerant and sand-fixing vegetation, and building shelterbelts along the boundaries
Grassland–bare soil
Continuous low-coverage grassland interspersed with few bare soil areas
Replanting for carbon sequestration
Increasing grassland carbon sink (soil and vegetation), the above-ground biomass, and then carbon sink and storage of the region via bare soil land management, grazing management, and ecological replanting
Floopplain–saline-alkali land
Floodplain near river and canals, bordered by saline-alkali land with sparse vegetation
Restoring for carbon sequestration
Improving soil fertility and maintaining soil carbon pool by soil mediation and maintenance of the saline-alkali land, planting saline-tolerant species, and introducing new planting technologies
Forest–farmland–water area
Shrub land–dry land–river and canal patches, with roads traversing through
Maintaining high carbon storage
Maintaining soil carbon pool and boosting vegetation carbon sink by conservation tillage, converting farmland to forest, naturalization of man-made forests, and mixed forest plantation
Grassland–highway
Narrow low-coverage grassland belts traversing bare rock or gravel areas, with highways in the center
Carbon sequestration monitoring
Maintaining grassland carbon pool (soil and vegetation) by natural grassland enclosure, rotational grazing, grazing intensity control, and shelterbelt construction; maintaining area carbon sink by planting along the highway
Tab.10
Fig.14
1
China Meteorological News. (2021, August 10). Report Made by the Working Group Ⅰ from IPCC AR6. China Meteorological Administration.
2
Xinhua News Agency. (2020, September 22). President Xi Jinping's Remarks at the General Debate of the 75th Session of the United Nations General Assembly. Chinese Government Website.
3
Xinhua News Agency. (2021, March 15). President Xi Jinping's Remarks at the ninth meeting of the Central Committee for Financial and Economic Affair. Chinese Government Website.
4
B., Lao , W., Zhuo , & R., Zhu (2020) The rebirth of tropical rainforest—Ecological restoration planning for Sanda Mountain of Xishuangbanna, China. Landscape Architecture Frontiers, 8 (31), 108– 125. https://doi.org/10.15302/J-LAF-1-040012
5
F., Lu , H., Hu , W., Sun , J., Zhu , G., Liu , W., Zhou , Q., Zhang , P., Shi , X., Liu , X., Wu , L., Zhang , X., Wei , L., Dai , K., Zhang , Y., Sun , S., Xue , W., Zhang , D., Xiong , L., Deng , B., Liu , L., Zhou , C., Zhang , X., Zheng , J., Cao , Y., Huang , N., He , G., Zhou , Y., Bai , Z., Xie , Z., Tang , B., Wu , J., Fang , G., Liu , & G., Yu (2018) Effects of national ecological restoration projects on carbon sequestration in China from 2001 to 2010. PNAS, 115 (316), 4039– 4044. https://doi.org/10.1073/pnas.1700294115
6
R., Hou , C., Xia , J., Chen , Q., Zheng , H., Li , J., Huang , X., Huang , J., Deng , X., Han , T., An , Y., Hao , & L., Gou (2022) Carbon storage and carbon sink of forest land and other biomass in the Yangtze River Economic Belt. Acta Ecologica Sinica, 42 (323), 9483– 9498.
7
L., Xie , Z., Bai , B., Yang , M., Chen , S., Fu , & Y., Mao (2023) Carbon sequestration assessment methods at home and abroad for terrestrial ecosystems: Research progress in achieving carbon neutrality. Earth Science Frontiers, 30 (32), 447– 462.
8
Z., Lin , P., Wang , Q., Liu , & Y., Yang (2022) Spatio-temporal evolution characteristics of cultivated land carbon storage and identification of carbon sink areas in Huaihai Economic Zone from 2005 to 2020. Transactions of the Chinese Society of Agricultural Engineering, 38 (319), 259– 268.
9
Y., Han , S., Zhang , & L., Yin (2019) Quantifying the carbon storage capacity and its spatial distribution patterns of green spaces in a metropolitan area: A case study of Seoul, South Korea. Landscape Architecture Frontiers, 7 (32), 55– 65. https://doi.org/10.15302/J-LAF-20190205
10
H., Zhang , Q., Peng , R., Wang , W., Qiang , & J., Zhang (2020) Spatiotemporal patterns and factors influencing county carbon sinks in China. Acta Ecologica Sinica, 40 (324), 8988– 8998.
11
H., Zhang , J., He , X., Yang , & Q., Peng (2022) Zoning and governance of county ecological space for the increase of carbon sinks: A case study of the Beijing-Tianjin-Hebei region. Planners, 38 (31), 32– 40.
12
J., Jiang , J., Xu , W., Wu , L., Zhou , & D., Sun (2014) Patterns and dynamics of China's human-nature carbon source-sink system. Journal of Natural Resources, 29 (35), 757– 768.
13
Y., Fan , & F., Wei (2022) Contributions of natural carbon sink capacity and carbon neutrality in the context of net-zero carbon cities: A case study of Hangzhou. Sustainability, 14 (35), 2680. https://doi.org/10.3390/su14052680
14
F., Kong , L., Ying , W., Wen , & M., Liang (2021) Exploring carbon sequestration and sink enhancement based on ecological restoration of territorial space. Natural Resource Economics of China, 34 (312), 70– 76.
15
M., Li , & C., Wu (2022) Application of NbS in terrestrial ecological restoration project to promote carbon sequestration and sink in China. Natural Protected Areas, 2 (34), 25– 31.
16
S., Piao , C., Yue , J., Ding , & Z., Guo (2022) Perspectives on the role of terrestrial ecosystems in the 'carbon neutrality' strategy. Science China Earth Sciences, 65 (36), 1178– 1186. https://doi.org/10.1007/s11430-022-9926-6
17
J., Zhao , Y., Liu , & F., Han (2023) Thoughts on the path of increasing carbon sink in grassland under carbon peak and carbon neutrality targets. Acta Agrestia Sinica.
18
Q., Zhou , Q., Wang , Z., Zheng , & W., Liu (2023) Carbon neutrality and ecological remediation in agricultural grain production. Journal of Agro-Environment Science, 42 (31), 1– 10.
19
W., Li , J., Li , Y., Zhang , P., Li , & J., Han (2022) Ecological restoration technologies for lake wetlands for carbon peaking and neutrality. Journal of Nanjing Forestry University (Natural Sciences Edition), 46 (36), 157– 166.
20
Yang, L. (2016). Evaluations of carbon sink benefit under the ecological restoration model of Karst rocky desertification [Master's thesis]. Guizhou Normal University.
21
B., Kang , M., Li , & H., Li (2021) A case study of Nature-based Solutions in coastal zone blue carbon ecosystems restoration. Landscape Design, (34), 10– 15.
22
X., Zhang , W., Wei , L., Zhou , Z., Guo , Z., Li , J., Zhang , & B., Jie (2021) Analysis on spatio-temporal evolution of ecological vulnerability in arid areas of northwest China. Acta Ecologica Sinica, 41 (312), 4707– 4719.
23
Y., Lu , Y., Zhao , & J., Dong (2022) Ecological security evaluation and driving force analysis of three-dimensional ecological footprint in northwestern China. Acta Ecologica Sinica, 42 (34), 1354– 1367.
24
J., Pan , & Y., Wen (2015) Estimation and spatial-temporal characteristics of carbon sink in the arid region of northwest China. Acta Ecologica Sinica, 35 (323), 7718– 7728.
25
Z., Pei , C., Zhou , H., Ouyang , & W., Yang (2010) A carbon budget of alpine steppe area in the Tibetan Plateau. Geographical Research, 29 (31), 102– 110.
26
Y., Wang , G., Luo , Y., Wang , Q., Han , B., Fan , & Y., Chen (2014) Vegetation and soil carbon density in arid region of Central Asia. Arid Land Geography, 37 (32), 239– 249.
27
Lai, L. (2010). Carbon emission effect of land use in China[Master's thesis]. Nanjing University.
28
M., Yang , X., Yang , Y., Zhao , Q., Huang , C., Li , W., Cao , A., Chen , Q., Gu , Z., Li , & S., Wang (2023) Estimated carbon storage and influencing factors of alpine grassland in the source region of the Yellow River. Acta Ecologica Sinica, 43 (39), 3546– 3557.
29
S., Wang , C., Zhou , & C., Luo (1999) Studying carbon storage spatial distribution of terrestrial natural vegetation in China. Progress in Geography, 18 (33), 238– 244.
30
X., Sun , & H., Liu (2010) Effects of land use change on wetland landscape connectivity and optimization assessment of connectivity—A case study of wetlands in the coastal zone of Yancheng, Jiangsu. Journal of Natural Resources, 25 (36), 892– 903.
31
F., Fu , Z., Liu , & H., Liu (2021) Identifying key areas of ecosystem restoration for territorial space based on ecological security pattern: A case study in Hezhou City. Acta Ecologica Sinica, 41 (39), 3406– 3414.
32
B., He , J., Ding , H., Li , B., Liu , & W., Chen (2018) Spatiotemporal variation of vegetation phenology in Xinjiang from 2001 to 2016. Acta Ecologica Sinica, 38 (36), 2139– 2155.
33
Q., Xiong , Y., He , T., Li , & L., Yu (2019) Spatiotemporal patterns of vegetation coverage and response to climatic and topographic factors in growth season in southwest China. Research of Soil and Water Conservation, 26 (36), 259– 266.
34
Y., He , Z., Kong , X., Hu , J., Zhang , M., Wang , C., Peng , & Q., Zhu (2022) Water and heat conditions separately controlled inter-annual variation and growth trend of NDVI in the temperate grasslands in China. Acta Ecologica Sinica, 42 (32), 766– 777.
35
S., Jiao , Y., Liu , Z., Han , K., Zhou , L., Hu , & T., Liu (2021) Determining priority areas for land ecological restoration based on ecological network-human disturbance: A case study of Changsha-Zhuzhou-Xiangtan Urban Agglomeration. Journal of Natural Resources, 36 (39), 2294– 2307.
36
R., Shao , W., Wang , K., Shi , & Y., Liu (2014) Research for restoration of soil and vegetation in human disturbance zone of road in high-cold grassland area. Research of Soil and Water Conservation, 21 (36), 181.
37
J., Wang , & J., Zhang (2001) Comparing several methods of assuring weight vector in synthetical evaluation. Journal of Hebei University of Technology, 30 (32), 52– 57.
38
X., Tao , R., Zhang , H., Xu , & J., Zhu (2006) Assessment of City's sustainable development based on improved entropy method. Journal of Arid Land Resources and Environment, 20 (35), 38– 41.
39
& K., Yu (1999) Landscape ecological security patterns in biological conservation. Acta Ecologica Sinica, 19 (31), 8– 15.
40
G., Yu , J., Zhu , L., Xu , & N., He (2022) Technological approaches to enhance ecosystem carbon sink in China: Nature-based Solutions. Bulletin of the Chinese Academy of Sciences, 37 (34), 490– 501.
41
G., Qin , & M., Tian (2022) The development opportunities and implementation path of forestry carbon sequestration under the target of carbon peak and carbon neutrality. Administrative Reform, (31), 45– 54.
42
C., Wang , R., Wang , & Z., Lin (2010) Carbon sequestration estimation by different tree species and reforestation types in forest ecosystem. Ecology and Environmental Sciences, 19 (310), 2501– 2505.
43
Y., Zhang , G., Yang , N., Liu , S., Chang , & X., Wang (2013) Review of grassland management practices for carbon sequestration. Acta Prataculturae Sinica, 22 (32), 290– 299.
44
C., Xue , Y., Li , C., Hu , & S., Yao (2022) Study on spatio-temporal pattern of conservation tillage on net carbon sink in China. Journal of Natural Resources, 37 (35), 1164– 1182.
45
J., Zheng , K., Cheng , G., Pan , P., Smith , L., Li , X., Zhang , J., Zheng , X., Han , & Y., Du (2011) Perspectives on studies on soil carbon stocks and the carbon sequestration potential of China. Chinese Science Bulletin, 56 (326), 2162– 2173.
46
H., Huo , J., Zhang , A., Ma , & J., Huo (2018) Progress and prospects of soil carbon cycle in arid deserts. Journal of Northwest Forestry University, 33 (31), 98– 104.
47
Z., Li , N., Shan , Q., Wang , W., Li , Z., Wang , S., Bao , H., Dou , W., Ao , B., Pang , & W., Wang (2022) Estimation of vegetation carbon source/sink and analysis of its influencing factors in Hulun Lake Basin from 2013 to 2020. Journal of Ecology and Rural Environment, 38 (311), 1437– 1446.
48
F., Qu , N., Lu , & S., Feng (2022) Effects of land use change on carbon emissions. China Population, Resources and Environment, 21 (310), 76– 83.
49
Y., Li , X., Hao , J., Zhang , X., Fan , & Z., Zhao (2022) Spatial and temporal variation of net carbon sink function of farmland in Aksu oasis in the past 17 years. Arid Zone Research, 39 (34), 1303– 1311.
50
M., Li , S., Liu , Y., Sun , & Y., Liu (2021) Agriculture and animal husbandry increased carbon footprint on the Qinghai-Tibet Plateau during past three decades. Journal of Cleaner Production, (3278), 123963.
51
Y., Wu , M., Zhang , M., Yang , & Y., Jun (2022) Exploration of the implementation of carbon neutralization in the field of natural resources under the background of sustainable development—An overview. International Journal of Environmental Research and Public Health, 19 (321), 14109.
52
Q., Xu , Y., Dong , & R., Yang (2018) Influence of the geographic proximity of city features on the spatial variation of urban carbon sinks: A case study on the Pearl River Delta. Environmental Pollution, 243 (3A), 354– 363.
53
Y., Cao , J., Wang , & G., Li (2019) Ecological restoration for territorial space: Basic concepts and foundations. China Land Science, 33 (37), 1– 10.
54
Y., Han , Q., Zhang , S., Zhang , & L., Yin (2021) Optimizing the habitat quality of the East Lake Scenic Area in Wuhan. Chinese Landscape Architecture, 37 (39), 95– 100.
55
S., Xu , H., Wang , & W., Kong (2021) Study on mountainous optimization of ecological security pattern based on MCR model from the perspective of disaster prevention: A case study of Beijing-Tianjin-Hebei mountainous area. Journal of Catastrophology, 36 (32), 118– 123.
