Grassland Resources Research Articles

青藏高原典型草地NDVI时空演变的季节差异及其气候驱动

PDF HTML阅读 XML下载 导出引用 引用提醒 青藏高原典型草地NDVI时空演变的季节差异及其气候驱动 DOI: 10.5846/stxb202201050028 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 第二次青藏高原综合科学考察研究项目（2019QZKK0305）；国家自然科学基金项目（41771233） Different spatiotemporal variations in seasonal NDVI and their climatic driving forces of a typical grassland on the Qinghai-Tibetan Plateau Author: Affiliation: Fund Project: The Second Qinghai-Tibetan Plateau Scientific Expedition and Research Program, China; The National Natural Science Foundation of China (General Program, Key Program, Major Research Plan) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:基于全球库存建模和制图研究（GIMMS）第三代归一化植被指数（NDVI3g）产品和气象数据，利用一元线性回归模型、偏相关分析和显著性T检验，分析了1982-2015年青藏高原高寒草甸和高寒草原春、夏、秋季NDVI时空演变的差异特征及其与气候因子的关系。研究表明：（1）高寒草甸春、夏、秋季NDVI整体均无明显变化趋势，高寒草原春季和夏季NDVI均显著增加，变化速率均为0.0002/a （P<0.05），而秋季NDVI变化趋势不明显。（2）空间上，高寒草甸春季NDVI显著增加面积占比31.95%，集中分布在祁连山区和三江源区，夏季NDVI显著增加的面积占比32.12%，主要分布在祁连山区、三江源地区和一江两河流域；秋季NDVI显著增加的比例为24.59%，集中分布于祁连山区和一江两河流域。高寒草原春、夏、秋季NDVI显著增加的区域均集中分布于西藏自治区北部和柴达木盆地南缘地区，分别占比44.20%、43.09%和37.99%。（3）高寒草甸春季和秋季NDVI均与气温显著正相关，偏相关系数达0.41（P<0.05）和0.23（P<0.05），夏季NDVI与气温、降水量和太阳辐射均呈显著相关性，偏相关系数分别为0.35（P<0.01）、0.56（P<0.01）和-0.57（P<0.01）；高寒草原春季NDVI与气温和降水量均呈显著正相关，且与降水量偏相关系数较高，为0.31（P<0.05），夏季NDVI与气温、降水量和太阳辐射均呈显著相关性，与降水量偏相关系数最高，为0.46（P<0.01），秋季NDVI与太阳辐射显著正相关。（4）空间上高寒草甸春季和秋季NDVI与气温呈正相关的像元分别占比76.50%和67.86%，集中于祁连山区和三江源区，夏季NDVI与降水量呈正相关的像元占比58.42%，与太阳辐射呈负相关的像元占比53.69%，均集中分布于祁连山区、三江源区和一江两河流域。高寒草原春季和夏季NDVI与降水量呈正相关的像元分别占比63.02%和67.62%，集中分布在西藏自治区西部和柴达木盆地南缘。研究可为保护青藏高原草地资源、管理高寒生态系统植被碳库以及推动青藏高原长效生态增汇提供科学依据。 Abstract:Based on the third-generation normalized difference vegetation index (NDVI3g) of GIMMS and meteorological datasets, this study analyzed different spatiotemporal variations in NDVI and corresponding relationships to climate factors during spring, summer, and autumn in alpine meadow and alpine steppe biomes on the Qinghai-Tibetan Plateau in 1982-2015, combining a unary linear regression model with partial correlation analysis and a significance t-test. Results are as follows:(1) Generally, the NDVI of the alpine meadow biome exhibited no significant changing trends during spring, summer, and autumn; however, the NDVI of the alpine steppe biome increased significantly during spring and summer at a rate of 0.0002/a (P<0.05), while no obvious trends were observed during autumn. (2) Spatially, 31.95% of NDVI in the alpine meadow biome exhibited significant increasing trends during spring, mainly in areas distributed throughout the Qilian Mountains and the Three River Nature Reserve, and 32.12% during summer, mainly in areas distributed throughout the Qilian Mountains, the Three River Nature Reserve, and the Yarlung Zangbo River as well as the basins of its two tributaries, and 24.59% during autumn, mainly in areas distributed throughout the Qilian Mountains and the Yarlung Zangbo River as well as the basins of its two tributaries. The alpine steppe biome exhibited significantly increasing NDVI trends during spring (44.20%), summer (43.09%), and autumn (37.99%), mainly in areas distributed throughout the northern Tibet Autonomous Region and southern margin of the Qaidam Basin. (3) For the alpine meadow biome, the area-averaged NDVI exhibited a significantly positive correlation to temperature during spring and autumn, with partial correlation coefficients of 0.41 (P<0.05) and 0.23 (P<0.05), respectively. During summer, the NDVI of alpine meadow areas significantly correlated to temperature, precipitation, and solar radiation, for which partial correlation coefficients were 0.35 (P<0.01), 0.56 (P<0.01), and -0.57 (P<0.01), respectively. For the alpine steppe biome, we observed a significantly positive correlation between NDVI and temperature and precipitation during spring, with a higher partial correlation coefficient of 0.31 with precipitation (P<0.05). Significant correlations were also observed between the NDVI and temperature, precipitation, and solar radiation during summer, with a higher partial correlation coefficient of 0.46 with precipitation (P<0.01). Moreover, a significantly positive correlation between NDVI and solar radiation was observed during autumn. (4) Spatially, proportions of positive correlations between NDVI and temperature during spring and autumn in the alpine meadow biome were 76.50% and 67.86%, respectively, mainly distributed in areas within the Qilian Mountains and the Three Rivers Nature Reserve. Although 58.42% of alpine meadow areas exhibited positive correlations between NDVI and precipitation during summer, only 53.69% exhibited negative correlations between NDVI and solar radiation during autumn, both situated within the Qilian Mountains, headwaters of the Three Rivers Nature Reserve, and the Yarlung Zangbo River as well as the basins of its two tributaries. For the alpine steppe biome, proportions of positive correlations between NDVI and precipitation during spring and summer were 63.02% and 67.62%, respectively, primarily distributed within the western Tibet Autonomous Region and southern margin of the Qaidam Basin. This study provides a scientific basis for the protection of grassland resources and the management of plant-based carbon pools in alpine ecosystems, while also promoting a long-term increase in ecologically-based carbon sinks on the Qinghai-Tibetan Platea. 参考文献 相似文献 引证文献

A dataset of UAV multispectral images for the grassland-livestock balance

The grassland-livestock balance system plays an important role in reconciling the protection of grassland resources with the sustainable development of animal husbandry. The accurate estimation of the grassland-livestock balance is the basis for the implementation of the grassland-livestock balance system. In order to explore the accurate calculation method of the important parameter, i.e. livestock grass demand in the calculation system, in this study, we set up an experimental area in the natural grassland of Hulunbuir, Inner Mongolia, to simulate a real grazing scene, and conducted 4 grazing experiments controlling the sheep number and grazing time. We obtained multispectral images of the experimental area before and after grazing were with the help of the UAV remote sensing, and carried out a quadrat survey. After data sorting and preprocessing, we produced this dataset of high spatial resolution image data and accurate quadrat investigation data. It can be applied to the research on the daily grass demand of grazing sheep on Hulunbuir meadow steppe in autumn. This dataset provides data support for the accurate estimation of local grassland-livestock balance, and is of great significance for the adaptive dynamic management of grass and livestock.

Research on Ecosystem Service Consumption in Guilin City

Research on ecosystem service consumption not only helps to reveal the utilization intensity and management level of the ecosystem in Guilin, but it also provides a scientific basis for ecosystem investment, trade, subsidies and taxation by the Guilin government departments. Based on household survey data of urban and rural ecological consumption, the physical quantity accounting method is adopted for multivariate statistical analyses, such as analysis of variance and multiple comparison. This analysis reveals the differences and changes in the consumption level, consumption structure and consumption pattern of the main ecological products in Guilin among the various counties. The results fit into four main themes. (1) The annual per capita consumption of the main ecological products in Guilin varies either extremely significantly or significantly among the counties, but the consumption level of ecological products varies according to the type of products. There are significant or extremely significant differences in the annual per capita consumption of cereals, melons and fruits, pork, poultry, beef and mutton, fresh eggs and milk between urban and rural residents. (2) There are extremely significant differences in the annual per capita consumption of fruits, pork, poultry, beef and mutton, fish, fresh milk and vegetable oil among urban residents in different counties. There are also extremely significant differences in the annual per capita consumption of cereals, pork, poultry and alcohol among rural residents in different counties, and significant differences in the annual per capita consumption of fresh eggs and milk. The consumption level of ecological products by urban and rural resident varies with the type of products. (3) The ecological consumption patterns of all counties in Guilin mainly follow the “cereal + vegetable + fruit + meat” pattern for urban residents and the “cereal + vegetable + meat” pattern for rural residents (except for the rural residents in Pingle, which show the “cereal + vegetable” pattern). The consumption structure of urban residents is better than that of rural residents. (4) There is a large gap between the ecological consumption of urban and rural residents in Guilin and China′s recommended standards, except for cereals and meat. The main problems are excessive meat intake, and insufficient intake of dark vegetables, fruits, eggs, milk and fish. Therefore, we should make full use of forestland, grassland, water and other resources in the area, and vigorously develop fishery, fruit and vegetable production and herbivorous animal husbandry to meet people′s ecological needs for dark fruits and vegetables, eggs, milk and fish in Guilin City.

Herder households' livelihood strategies as a response to payments for grassland ecosystem services in China

AbstractHerder households' response is critical in determining the effectiveness of payments for grassland ecosystem services (PGES). This study aimed to comprehensively analyze the influencing factors and processes of herder households' response to PGES using the sustainable livelihood approach. Here, we were the first to classify the ways herder households respond to PGES from the perspective of livelihood strategies, and proposed a sustainable livelihood indicator framework applicable to herder household research. According to the framework, we combined path analysis and statistical analysis to carry out empirical analysis in a typical area. The results show that the response strategies could be divided into three types, which rated by popularity from low to high, were reduction in herd counts (19.1%), livelihood diversification (27.7%) and industrial upgrading (53.1% max). Their formation was influenced by various factors, such as the PGES, vulnerability context, livelihood assets, and livelihood outcomes. In general, strict supervision (influence coefficient 0.46) helped reduce livestock headcounts, especially in small and medium households, which used to be the main bodies of overloading. Households with rising living standards tended to explore off‐farm livelihoods, but there were also some households that did so because of disagreement with PGES. Households with higher vulnerability and higher livelihood assets tended to cope with the shortage of grassland through industrial upgrading, thereby achieving a balanced utilization of grassland resources. This study not only makes an important supplement to PGES and sustainable livelihood theory but also provides an important reference for grassland ecological protection practices around the world.

From Forests to the Coast - Multidisciplinary Investigation of Human Adaptations at the Mini-athiliya Shell Midden, Sri Lanka

Over the last three decades, Sri Lanka has risen to international prominence as a key area for exploring past forager adaptations. Much of this discussion has focused on the lowland rainforests of the Wet Zone of the island, and their preservation of the earliest fossils of our species, bone tools, and microlithic technologies in the region ca. 45,000 years ago. It has been recognized that the northern and southern coasts of Sri Lanka represent crucial locales for studying human occupation and adaptation through the Pleistocene and Holocene. Here, we revisit the important shell midden site of Mini-athiliya (dating to ca. 4,000 cal. years BP), on the southern coast of Sri Lanka, which has yielded human remains alongside microlithic stone tools and animal remains. We present a comparative analysis of body size variation of the human remains belonging to the HMA 6 adult skeleton from Mini-athiliya with a wider database of foragers to investigate local adaptations. We also apply stable carbon and oxygen isotope analysis to the tooth enamel of four other individuals documented at Mini-athiliya in order to determine their dietary reliance on forest, grassland, or coastal resources. Together, our results highlight that, rather than a clear distinction between earlier forest adaptations and later coastal specialisation, the Mini-athiliya individuals provide evidence for a plastic spectrum of ecological adaptation. We argue for continued research on how human populations in different parts of the island interacted and adapted to its diverse tropical settings across space and time.

Spatial and temporal distribution of rural settlements and influencing mechanisms in Inner Mongolia, China

Revealing the patterns and influencing mechanisms of spatial and temporal distribution of rural settlements is crucial for rural revitalization and sustainable development. However, our limited understanding of the rural settlements in China's ethnic minority border areas has hindered the process of their agricultural and rural modernization. Based on data on rural settlements in Inner Mongolia, China in four periods between 1990 and 2020, this study reveals its spatial and temporal distribution characteristics and describes the dynamic transformation process of settlement. Using a geographical detector approach, 17 factors are explored to identify the influencing mechanisms of each factor on the distribution of rural settlements in different regions. The results show obvious regional differences in the spatial distribution of rural settlements in Inner Mongolia, with the largest kernel density values in the west (Hetao irrigation area) and higher kernel densities in the central (Hohhot) and the east (Chifeng and Tongliao). While rural population decreases, rural settlements expand into cultivated land, grassland, and unused land resources. Its spatial distribution is significantly influenced by the factors of distance to cultivated land, distance to towns, and population density. The east of the study area is mainly controlled by temperature, while vegetation type and vegetation coverage have a greater impact in the west. The interactions between two influencing factors possess bilinear or nonlinear enhancement relationships. This study enriches the understanding of the rural settlements in ethnic minority border areas, which provide reference for the improvement of rural human settlement environment in Inner Mongolia.

Grassland Transfer and Its Income Effect: Evidence from Pastoral Areas of the Qinghai–Tibet Plateau

Under the condition of different endowment factors of herders and imperfect market mechanisms, grassland transfer can promote the redistribution and rational utilization of grassland resources, which has a crucial impact on herders’ livelihood. This study fully examined how the grassland rental market improves herders’ income and to what extent, using unbalanced panel data with 560 herder households in the Qinghai–Tibet Plateau pastoral areas. A fixed effect model was used as the baseline model. The instrumental variable approach and propensity score matching method were utilized to address the endogeneity problem and sample selection bias. Finally, the mediating effect model was used to analyze the path mechanism of grassland transfer in/out on herder income. The results showed that the total household income increased significantly after participating in grassland transfer. Grassland rent-in increased livestock income, and grassland rent-out increased non-livestock income. After correcting for the selection bias, the income effect of grassland transfer became larger. The grassland rent-in increased the livestock income by promoting production investment. Grassland rent-out increased the non-livestock income by promoting non-pastoral employment.

Spatial and Temporal Characteristics of Ecosystem Service Trade-Off and Synergy Relationships in the Western Sichuan Plateau, China

Clarifying the complex relationships among ecosystem services (ESs) and the driving mechanisms of ecosystem service (ES) is essential for supporting regional ES and ecological sustainability. Although studies on ES relationships provide guidance for regional ecological management, the driving mechanisms of ES have not been adequately studied, especially in areas with complex natural environments and progressive urbanization. Combined with the data on land use, climate, NDVI, and soil data, this paper aims to explore this issue by analyzing the relationships among ESs and the driving mechanisms of ESs in the western Sichuan Plateau region of China. Firstly, the temporal and spatial distribution characteristics of five ecosystem services (food supply, water supply, habitat quality, soil conservation, and carbon storage) from 2000 to 2020 were analyzed by the InVEST model. Second, the trade-offs/synergistic relationships among ESs were analyzed using SPSS as well as the Pearson product-moment correlation coefficient method in MATLAB. Finally, the Geodetector model was further used to reveal the influencing factors of ecosystem services in the western Sichuan Plateau. The results showed that: (1) Water supply decreased in the western Sichuan Plateau from 2000 to 2020, but increased in the eastern part; habitat quality was generally good in the whole Sichuan Plateau, but decreased in some areas; carbon storage showed an overall improving trend; soil conservation showed an overall increasing and then decreasing trend, and food supply services showed an increasing trend. (2) From 2000 to 2020, food supply and other services in the western Sichuan Plateau were in a trade-off relationship; all other service pairs showed a synergistic relationship. (3) In terms of space, the relationships between ecosystem services showed spatial heterogeneity. There was a synergistic relationship between food supply and habitat quality in some areas, such as Litang County and Xinlong County, and there was a trade-off relationship between water supply and carbon storage services in some areas, such as Ruoergai County and Daocheng County, etc. (4) The Geodetector results showed that food supply and soil conservation were mainly influenced by the slope (0.682, 0.672), annual precipitation was the strongest explanation for water supply (0.967), and habitat quality and carbon storage were the most influenced by NDVI (0.876, 0.828); meanwhile, each ecosystem service was interactively influenced by multiple factors. Based on the results, we proposed ecological management recommendations for the western Sichuan Plateau, the most important one being that the western Sichuan Plateau should protect and rationally use the existing natural resources, especially the existing forest and grassland resources, and at the same time reform the agricultural structure and scientifically plan urban development, to promote the coexistence of cities and nature. We took the western Sichuan Plateau of China, where urbanization and a complex natural environment are in opposition, as an example, to explore its ecosystem services, relationships, and driving mechanisms, and then put forward suggestions on ecological management and control, providing a reference for future regional coordination between urbanization and the natural environment.

Sentinel-2 Images Based Modeling of Grassland Above-Ground Biomass Using Random Forest Algorithm: A Case Study on the Tibetan Plateau

Accurate information on grassland above-ground biomass (AGB) is critical to better understanding the carbon cycle and conserve grassland resources. As a climate-sensitive key ecological function area, it is important to accurately estimate the grassland AGB of the Tibetan Plateau. Sentinel-2 (S2) images have advantages in reducing mixed pixels and the scale effect for remote sensing, while the data volume is correspondingly larger. In order to improve the estimation accuracy while reducing the data volume required for AGB estimation and improving the computational efficiency, this study used the Recursive Feature Elimination (RFE) algorithm to find the optimal feature set and compared the performance of the Cubist, Gradient Boosting Regression Tree (GBRT), random forest (RF) and eXtreme Gradient Boosting (XGBoost) algorithms for estimating AGB. In this study, ten S2 bands, ten S2-derived vegetation indexes, 218 pieces of AGB field survey data, four types of meteorological data and three types of topographic data were used as the alternative input features for the AGB estimation model. The impurity and permutation importance were used as the feature importance calculation method input to the RFE, and the Cubist, GBRT, RF and XGBoost algorithms were used to construct the AGB estimation models. The results showed that the RF algorithm based on the monthly average temperature (T), elevation, Normalized Difference Phenology Index (NDPI), Normalized Difference Infrared Index (NDII) and Palmer Drought Severity Index (PDSI) performed best (R2 = 0.8838, RMSE = 35.05 g/m2, LCCC = 2.44, RPPD = 0.91). The above findings suggest that the RF model based on the features related to temperature, altitude, humidity and leaf water content is beneficial to estimate the grassland AGB on the Tibetan Plateau.

Water yield response to plant community conversion caused by vegetation degradation and improvement in an alpine meadow on the northeastern Tibetan Plateau

Water provision is an important ecological function of alpine meadows on the Tibetan Plateau. Quantitative assessment of the effects of vegetation change induced by vegetation degradation and improvement on water yield (WY) in alpine meadows is urgent for rational water and grassland resources conservation and management. Previous studies mainly focused on the effects of vegetation coverage. What is less clear is how the WY of alpine meadow changes under plant community conversion caused by vegetation degradation and improvement. To test the hypotheses that lysimeter drainage (LD) decreases in the vegetation-degraded meadow and recovers in the vegetation-improved meadow, and the LD decreases as the stress tolerance of dominant strategy decreases, in situ lysimeters with intact monoliths of well-vegetated alpine meadows subjected to vegetation intact (sedge-dominated), degraded (forb-dominated) and improved (fast-growing grass-dominated) were employed, and then plant communities among treatments were compared based on the quantitative competitor, stress tolerator, and ruderal (CSR) theory. Compared to the vegetation-intact monoliths, the LD of vegetation-degraded monoliths was 59 % lower owing to the deeper roots and greater aboveground growth. The LD of vegetation-improved monoliths was 83 % higher than that of vegetation-degraded monoliths due to the shallower roots but was 25 % lower than that of vegetation-intact monoliths due to the greater aboveground growth. The LD decreased along a plant community conversion gradient in which the S-selection of the dominance strategy decreased (R2 = 0.34, P = 0.022) and the C-selection increased (R2 = 0.71, P < 0.001), likely due to the significant covariation between community-weighted CSR strategy with eco-hydrological plant and soil properties. These results indicated that the community conversion caused by vegetation degradation reduces the WY of alpine meadows, and sowing fast-growing grasses can only partly restore this function. Application of stress-tolerant plants for vegetation improvement may be more efficient in recovering the WY of degraded meadows, especially in flat meadows under humid climate.

Heterogeneous responsibilities of three grassland resource governance modes in Inner Mongolia, China

Grassland resource governance is an important part of ecological civilization construction, and it directly affects grassland governance performance. This study deploys principal-agent theory and uses social network analysis to compare grassland resource governance modes in China in terms of institutional settings and institutional network characteristics. This study found three types of grassland resource governance modes: self-designed, docked, and integrated. The self-designed mode forms a network structure with dual centers and multiple members, and has the second-best structural mode of the three types. The docked mode forms a network structure with a single center in which the institution is the absolute core and is relatively divergent. It has the weakest structural advantage of the three types. The integrated mode forms a network structure with a single institution at the core and other institutions distributed evenly throughout the structure. This mode has the strongest structural advantage among the three types. This study offers the practical application of improving the practice of grassland governance in China and is theoretically significant because it can contribute to improving grassland governance modes and enriching the public goods resources governance.

How much aboveground net primary production can be used for human activities in the alpine grasslands in the Three Rivers Source Region (TRSR), China?

Sustainable management of grasslands has always been an urgent issue for policy-makers. The three rivers source region (TRSR) contains widely distributed natural grasslands and is sensitive to climate warming. To enable the sustainable development of the human-nature system in the TRSR, we propose a novel indicator based on the allocation of aboveground net primary production (ANPP). The indicator we proposed is the ANPP that can be used for human activities (UANPP). In the study, we simulated the spatial and temporal patterns of the UANPP in the alpine grasslands in the TRSR during 1979–2016 and explored the main driving factors of the UANPP. The results revealed that (a) the annual total UANPP in the TRSR was 13.22 TgC, approximately accounting for 47% of total ANPP. (b) The areas with negative UANPP values accounted for 16% of the entire TRSR, and they were primarily located within the Nature Reserve of the Yangtze and Yellow river source regions, while three-quarters of the area exhibited improvement trends. (c) The regional mean UANPP significantly increased during 1979–2016, at a rate of 0.28 gC m−2 yr−1 (p < 0.01). In the entire TRSR, 87% of the area exhibited increasing trends. (d) The UANPP in most areas of the TRSR was strongly correlated with precipitation, and the effect of human activities on the UANNP increased slightly during the 38 year study period. The UANPP represents the upper limit of human use of nature. These findings provide a reference for policy-makers to make decisions toward human-nature system sustainability while meeting human needs for grassland resources. ANPP allocation between nature and human system is a potentially important tool from the standpoint of sustainable development.

The urgent need to develop a new grassland map in China: based on the consistency and accuracy of ten land cover products.

Grasslands are the most dominant terrestrial ecosystem in China, but few national grassland maps have been generated. The grassland resource map produced in the 1980s is widely used as background data, but it has not been updated for almost 40 years. Therefore, a reliable map depicting the current spatial distribution of grasslands across the country is urgently needed. In this study, we evaluated the grassland consistency and accuracy of ten land cover datasets (GLC2000, GlobCover, CCI-LC, MCD12Q1, CLUD, GlobeLand30, GLC-FCS30, CGLS-LC100, CLCD, and FROM-GLC) for 2000, 2010, and 2020 based on extensive fieldwork. We concluded that the area of these ten grassland products ranges from 107.80×104 to 332.46×104 km2, with CLCD and MCD12Q1 having the highest area consistency. The spatial and sample consistency is highest in the regions of east-central Inner Mongolia, the Qinghai-Tibet Plateau and northern Xinjiang, while the distribution of southern grasslands is scattered and differs considerably among the ten products. MCD12Q1 is significantly more accurate than the other nine products, with an overall accuracy (OA) reaching 77.51% and a kappa coefficient of 0.51; CLCD is slightly less accurate than MCD12Q1 (OA=73.02%, kappa coefficient=0.45) and is more conducive to the fine monitoring and management of grassland because of its 30-meter resolution. The highest accuracy of grassland was found in the Inner Mongolia-Ningxia region and Qinghai-Tibet Plateau, while the accuracy was worst in the southeastern region. In the future grassland mapping, cartographers should improve the accuracy of the grassland distribution in South China and regions where grassland is confused with forest, cropland and bare land. We specify the availability of valuable data in existing land cover datasets for China's grasslands and call for researchers and the government to actively produce a new generation of grassland maps.

Extraction of Mountain Grasslands in Yunnan, China, from Sentinel-2 Data during the Optimal Phenological Period Using Feature Optimization

The timely and accurate mapping of the spatial distribution of grasslands is crucial for maintaining grassland habitats and ensuring the sustainable utilization of resources. We used Google Earth Engine (GEE) and Sentinel-2 data for mountain grassland extraction in Yunnan, China. The differences in the normalized vegetation index in the time-series data of different ground objects were compared. February to March, during grassland senescence, was the optimum phenological stage for grassland extraction. The spectral, textural of Sentinel-2, and topographic features of the Shuttle Radar Topography Mission (SRTM) were used for the classification. The features were optimized using the recursive feature elimination (RFE) feature importance selection algorithm. The overall accuracy of the random forest (RF) classification algorithm was 91.2%, the producer’s accuracy of grassland was 96.7%, and the user’s accuracy of grassland was 89.4%, exceeding that of the cart classification (Cart), support vector machine (SVM), and minimum distance classification (MDC). The SWIR1 and elevation were the most important features. The results show that Yunnan has abundant grassland resources, accounting for 18.99% of the land area; most grasslands are located in the northwest at altitudes above 3200 m and in the Yuanjiang River regions. This study provides a new approach for feature optimization and grassland extraction in mountainous areas, as well as essential data for the further investigation, evaluation, protection, and utilization of grassland resources.

Assessing the Spatio-Temporal Pattern and Development Characteristics of Regional Ecological Resources for Sustainable Development: A Case Study on Guizhou Province, China

Sustainable development is a common challenge for all global economies, and the assessment of the spatial distribution and development process of ecological resources is the basis of sustainable development. Considering the heterogeneity of regional ecological resource endowment, it is necessary to conduct a targeted assessment for different regions. In this study, we selected Guizhou Province, which is rich in ecological resources, but has a fragile environment, as our study area, and cultivated land, woodland, grassland, and water resources were selected as critical evaluation indicators. Notably, we applied Kernel density analysis methods, based on the remote sensing data of 2000, 2005, 2010, 2015, and 2020, to explore the spatiotemporal distribution characteristics and evolution pattern of regional ecological resources. The results indicated that the evolution of ecological resource development in Guizhou could be divided into three phases: degenerative (2000–2005), recovery (2005–2015), and development (2015–2020). The spatial distribution of Guizhou’s ecological resource was shown to be heterogeneous in the north and south and more homogeneous in the middle regions. Guizhou has diverse land-use types, with obvious regional differences in land-use structure. Notably, even though the development of ecological resources in Guizhou has improved, the development and utilization degree of ecological resources is still low, and the ecological damage is serious. This study can be used as a scientific reference by policymakers and decisionmakers to develop new regulations for ecological resources protection and sustainable development in China. We suggest that different regions should adopt more detailed measures; particularly, it is important to establish a spatial governance system to promote ecological resources development in the context of local conditions.

A simple, fast, and accurate method for land cover mapping in Mongolia

Low accuracy of global land cover (LC) products at local and regional scales is concerning, because of its huge impact on downstream applications. Therefore, developing a method for high accuracy LC maps at local and regional scale is of utmost importance. Taking Mongolia as a case study, we proposed a simple, fast, and accurate method to produce annual LC maps with 250 m spatial resolution from 2001 to 2020 using MODIS data. Our products have higher spatial resolution and higher accuracy (Overall Accuracy ∼90%) compared to MCD12Q1. These new maps are critical e.g., for land degradation research, and desertification/forest cover monitoring. Especially, information on grassland ecosystems is of utmost importance for Mongolia since more than half of the country economically depends on grassland resources. Therefore, Mongolia will benefit from the new dataset. Furthermore, due to the simplicity of the method, it can be easily applied and transferred to other regions.

Research on Service Value and Adaptability Zoning of Grassland Ecosystem in Ethiopia

The evaluation of the ecosystem service value (ESV) and its regionalization toward coordinating ecological protection and socioeconomic development is of great significance. In this study, we developed a classification method based on the Random Forest algorithm and a feature optimization method to identify grassland types. Then, we proposed an approach to quantitatively evaluate the ESV of the grassland ecosystem in Ethiopia, in which net primary production derived from remote sensing was used to evaluate organic matter production value (ESV1), promoting nutrient circulation value (ESV2), and gas regulation value (ESV3), the RUSLE model was used to evaluate soil conservation value (ESV4), and cumulative rainfall was used to calculate water conservation value (ESV5). By integrating the mean ESV under various influencing factors, the zoning map of grassland ecosystem service value was obtained. Our study found that more fine grassland types can be well classified with the overall accuracy of 86.52%. And the classification results are the basis of the ESV analysis. The total ESV of grassland ecosystems was found to be USD 105,221.72 million, of which ESV4 was the highest, accounting for 44.09% of the total ESV. The spatial analysis of ESV showed that the differences were due to the impacts of grassland types, elevation, slope, and rainfall. It was found that the grassland is suitable to grow in the elevation zone between approximately 1000 and 2000 m, and the larger the slope and rainfall are, the greater the mean ESV is. The zoning map was used to conclude that the areas from approximately the fourth to sixth level (only 34.78% of the total grassland area, but 65.94% of the total ESV) have better growth status and development potential. The results provide references and bases to support the local coordination and planning of various grassland resources and form reasonable resource utilization and protection measures.

Status of grassland resources utilization in Ili River Valley and countermeasures for sustainable utilization

From the perspective of grassland resources and their sustainable utilization, this paper expounds the type characteristics and utilization status of grassland resources in the Ili River Valley, and analyzes the main problems of grassland re-sources in the Ili River Valley, such as the annual increase of grassland degradation area, the increasingly serious soil erosion, the imbalance between seasons and years of grassland production, and the imperfect mechanism of grassland ecological protection, restoration and management. This paper discusses the driving mechanism affecting the productivity of grass-land resources, and puts forward the corresponding countermeasures in the sustainable utilization of grassland ecosystem, such as strengthening the management of grassland re-sources, establishing a grass seed gene bank and screening native grass species, implementing the construction of grassland ecological restoration, strengthening grassland ecological monitoring and actively promoting ecological tourism.

Hyperspectral Monitoring Driven by Machine Learning Methods for Grassland Above-Ground Biomass

Above-ground biomass (AGB) is a key indicator for studying grassland productivity and evaluating carbon sequestration capacity; it is also a key area of interest in hyperspectral ecological remote sensing. In this study, we use data from a typical alpine meadow in the Qinghai–Tibet Plateau during the main growing season (July–September), compare the results of various feature selection algorithms to extract an optimal subset of spectral variables, and use machine learning methods and data mining techniques to build an AGB prediction model and realize the optimal inversion of above-ground grassland biomass. The results show that the Lasso and RFE_SVM band filtering machine learning models can effectively select the global optimal feature and improve the prediction effect of the model. The analysis also compares the support vector machine (SVM), least squares regression boosting (LSB), and Gaussian process regression (GPR) AGB inversion models; our findings show that the results of the three models are similar, with the GPR machine learning model achieving the best outcomes. In addition, through the analysis of different data combinations, it is found that the accuracy of AGB inversion can be significantly improved by combining the spectral characteristics with the growing season. Finally, by constructing a machine learning interpretable model to analyze the specific role of features, it was found that the same band plays different roles in different records, and the related results can provide a scientific basis for the research of grassland resource monitoring and estimation.

Study on the current situation of grassland resources and ecological environment protection countermeasures in Sichuan Province

Sichuan Province is rich in grassland resources which is one of the five pastoral areas in China. It is an important part of the national Qinghai–Tibet plateau ecological barrier area and has a very important strategic position in the country. Starting from the current situation of grassland resources in Sichuan Province, based on the achievements and existing problems of grassland ecological protection, this paper puts forward countermeasures for grassland ecological protection in Sichuan, aiming to better promote the high-quality development of grassland in Sichuan and the construction of ecological barriers in the upper reaches of the Yangtze River and the Yellow River.