Grain For Green Program Research Articles

Cropping System and Technology Responses of Rainfed Agriculture to Conservation Set-Asides in China Under the Grain for Green Program

Cropping System and Technology Responses of Rainfed Agriculture to Conservation Set-Asides in China Under the Grain for Green Program

The Role of Climate Change and Human Intervention in Shaping Vegetation Patterns in the Fen River Basin of China: Implications of the Grain for Green Program

The Fen River Basin (FRB), an ecologically fragile region in China, exemplifies the intricate interplay between vegetation dynamics and both climatic and human-driven factors. This study leverages a 40-year (1982–2022) dataset, utilizing the kernel-based normalized difference vegetation index (kNDVI) alongside key climatic variables—rainfall (PRE), temperature (TMP), and solar radiation (SRAD)—to investigate vegetation variations and their drivers in the FRB, particularly in relation to the Grain for Green Program (GGP). Our analysis highlights significant greening across the FRB, with the kNDVI slope increasing by 0.0028 yr−1 and green-covered areas expanding by 92.8% over the study period. The GGP facilitated the greening process, resulting in a notable increase in the kNDVI slope from 0.0005 yr−1 to 0.0052 yr−1 and a marked expansion in the area of significant greening from 24.6% to 95.8%. Regional climate shifts, characterized by increased warming, heightened humidity, and a slight rise in SRAD, have further driven vegetation growth, contributing 75%, 58.7%, and 23.6% to vegetation dynamics, respectively. Notably, the GGP has amplified vegetation’s sensitivity to climatic variables, with areas significantly impacted by multiple climate factors expanding from 4.8% to 37.5%. Specially, PRE is the primary climatic influence, impacting 71.3% of the pertinent regions, followed by TMP (60.1%) and SRAD (30%). The integrated effects of climatic and anthropogenic factors, accounting for 47.8% and 52.2% of kNDVI variations, respectively, collectively influence 96% of the region’s vegetation dynamics. These findings underscore the critical role of climate change and human interventions in shaping vegetation patterns and provide a robust foundation for refining ecological conservation strategies, particularly in the context of global warming and land-use policies.

Trade-offs between grain supply and soil conservation in the Grain for Green Program under changing climate: A case study in the Three Gorges Reservoir region

Understanding the trade-offs between ecological benefits and cost of grain supply caused by ecosystem restoration is essential for decision-making. Nevertheless, due to climate change, the benefits of ecosystem restoration and cost of grain supply change across various spatial locations, thereby complicating the trade-offs. Taking one of China's largest scale ecosystem restorations, the Grain for Green Program (GGP), as an example, this study used the Three Gorges Reservoir (TGR) region as the case study area and combined the crop environment resource synthesis (CERES)-Crop model, future land-use simulation (FLUS), and the revised universal soil loss equation (RUSLE) to simulate future grain supply and soil erosion during 2021–2050 under three climate change and socioeconomic development scenarios (SSP1-2.6, SSP2-4.5, SSP5-8.5) in the TGR region. The results showed that: (1) Until 2050, the implementation of GGP would bring a large soil conservation benefit by reducing soil erosion of 2.47–5.68 million tons, at the cost of 130,277–660,279 tons decrease in grain production in the TGR region. (2) Under SSP5-8.5 climate change scenario with the highest rainfall in the future, the GGP would maintain the greatest soil conservation benefits, resulting in a total amount of soil erosion decrease by 2.55 to 5.68 million tons. (3) Trade-offs between benefit of reducing soil erosion and cost of grain supply vary considerably across income. Specifically, GGP benefits are greater under low-income and higher-emission scenarios, with significant gains in soil erosion control and less impact on grain supply. In contrast, in high-income and low-emission scenarios, the GGP results in less soil erosion control and greater impact on grain supply.

The social-ecological benefits of grain for green program based on coupled coordination network: Taking the China’s Loess Plateau as an example

The Grain for Green Program (GFGP) is the world’s largest payment for ecosystem services (PES). In the past 20 years, the Chinese government has implemented three stages of GFGP, which have profoundly affected the social-ecological benefits (SEB) of China’s Loess Plateau (LP), one of the regions with the most severe soil erosion and the most fragile ecological environment in the world. Therefore, we explored the changes and coupling coordination relationships of LP’s SEB in the past three stages of GFGP, and examined the spatial correlation network relationships between various units and their roles of GFGP, which was particularly important for the rationality and implementation direction of LP’s GFGP in the future. We found that in different GFGP stages, changes in LP’s SEB showed stage differences and spatiotemporal differences. The comprehensive social benefits (CSB) changed slowly (1.342 dropped to 1.232), and there was an obvious “northwest-southeast” regional division in space. The changes in comprehensive ecological benefits (CEB) fluctuated more obviously (1.481, 1.638, 0.597). After experiencing significant improvements of CEB in two stages, it entered a bottleneck period in the third stage. For a long time, the LP’s SEB have been in a state of coupling coordination, but the coupling coordination degree dropped to 0.493 in the third stage. With climate change, the continuous increase in potential grain yield has led to increasing losses in CSB. It was difficult to promote further coordination of LP’s SEB by accelerating the improvement of CEB. The coupling coordination degree has gradually moved from overall coupling coordination to mild imbalance. At the same time, the overall density of the SEB coupling coordination space network correlation was 0.218, which has shown an obvious network structure, and formed four major sectors: main beneficiary sector, broker sector, net overflow sector, and bidirectional overflow sector in each stage of GFGP. The role of each county has undergone regional changes in the entire GFGP, and there were recurring power transmission mechanisms and complex network formation factors. Based on this, we proposed to promote the coupling coordination and positive network transmission of SEB in the next stage of LP’s GFGP through “low-carbonization of agricultural production”, “further improvement of the compensation mechanism”, and “fusion of power transmission mechanism and network formation factors”.

Returning Cropland to Grassland as a Potential Method for Increasing Carbon Storage in Dry-Hot Valley Areas

A key aspect of mitigating global climate warming is enhancing the carbon storage capacity of terrestrial ecosystems. China’s Grain for Green Program (GFGP) is the largest ecological restoration project in the world, which is closely associated with land use change. A systematic assessment of the GFGP’s impact on regional carbon storage is of great significance for promoting regional development and maintaining ecosystem stability. Therefore, this study selects a typical dry-hot valley area—Yanjin County—as the study area, which serves as an ecological protection barrier in Southwest China. We employed the InVEST model and Geo-detector model based on land use data from three periods (2000, 2014, and 2019), combined with static overlay analysis methods, in order to evaluate the impact of the implementation of GFGP on the spatial and temporal distribution of carbon storage. We also explored the driving factors of the spatial differentiation of carbon storage. The results indicate that, since the implementation of the GFGP, a total of 180.03 km2 of cropland has been converted to forestland, increasing the forest cover rate from 81.83% to 83.37%. The project has contributed 5.88 × 105 t to regional carbon storage, effectively offsetting carbon emissions caused by human activities such as urban expansion while also promoting the growth of regional carbon storage. The implementation of the GFGP has led to changes in three types of land use. Among them, converting cropland to forestland (3262 t/km2) is the most effective carbon sequestration method, and converting cropland to grassland (2530 t/km2) has shown great potential in carbon sequestration. Additionally, the study found that elevation (0.038–0.059) is the main factor affecting the spatial differentiation of carbon storage, and the interaction between elevation and other factors can effectively enhance the carbon sequestration capacity of regional ecosystems. Overall, the GFGP not only plays a significant role in combating climate warming but also makes an important contribution to improving the stability and sustainability of regional ecosystems.

Impact of land use evolution on the value of ecosystem services in the returned farmland area of the Loess Plateau in northern Shaanxi

The Grain-for-Green Program (GGP) has been contributing to changes in the nationwide use of land and vegetation, further changing ecosystem services (ESs). However, the influence of GGP on ESs, in terms of land use evolution remains elusive. This study is conducted based on a dataset collected every five years for the past 30 years. This dataset includes land use statistics and is obtained from Landsat images and the random forest algorithm. Land use evolution in the Loess Plateau in northern Shaanxi from 1990 to 2020 is systematically analyzed. The interest transfer method is adopted to compute the ecosystem service value (ESV), and the willingness and economic affordability are included in the evaluation model. Finally, a cross-sensitivity coefficient is specified to reveal the effects of land use evolution on the ESV in the studied area. The results are as follows: (1) Land use changes mainly occurred on farmland, forest, and orchards. In the past 30 years, the area of cultivated land showed a decreasing trend, whereas the land areas used for other purposes increased. (2) In the same period, the ESV of the investigated plateau continued to rise, increasing by 5.12 billion USD in total. Additionally, the ESV provided by secondary services increases in the following order: regulating services > supporting services > provisioning services > cultural services. (3) The cross-sensitivity coefficient showed that the net transition among forest, grassland, orchard, and unused land in the studied region is relatively sensitive, and a larger transition span of land utilization leads to a stronger effect on the ESV. This study offers crucial data for the compensation of interregional ecology and provides model cases for other regions for ecosystem management.

Analysis of Changes in Runoff and Sediment Load and Their Attribution in the Kuye River Basin of the Middle Yellow River Based on the Slope Change Ratio of Cumulative Quantity Method

Climate change and human activities exert significant influence on the water–sediment relationship in arid and semi-arid regions. Therefore, comprehending the underlying mechanisms is crucial for the effective management of water and soil resources, as well as integrated watershed management. This research focuses on the Kuye River watershed (KYH_W) in the middle reaches of the Yellow River in China, along with its sub-watersheds Wangdaohengtazi (WDHT_SW) and Xinmiaosi (XM_SW). This paper utilizes the Mann–Kendall non-parametric test and the double cumulative curve method to examine the interannual trends of runoff, sediment transport, precipitation, temperature, and NDVI factors. Furthermore, the method of the slope change ratio of cumulative quantity (SCRCQ) is utilized to quantitatively evaluate the impacts and contribution rates of climate change and human activities on water–sediment changes within each watershed. The results are as follows: (1) From 1969 to 2019, the entire watershed experienced a significant decrease in both runoff and sediment transport, with 1997 marking the year of abrupt change. However, following 2012, the KYH_W and WDHT_SW exhibited a noticeable rebound in runoff. (2) Human activities predominantly contribute to the reduction in water and sediment in the watershed. (3) After the abrupt change, between 1998 and 2011, the contribution rates of climate change and human activities to the annual runoff reduction in the entire KYH_W reached 33% and 64%, respectively. Moreover, these rates for sediment transport reduction reached 26% and 74%, respectively. Subsequently, after 2012, the contribution rates of both factors to the increase in watershed runoff reached 29% and 71%, respectively. Factors other than the NDVI, within human activities, played a dominant role in augmenting the watershed’s runoff. (4) Prior to 2011, changes in vegetation cover resulting from the Grain for Green Program, as measured by the NDVI, emerged as the primary factor responsible for reduced runoff in the watershed. Conversely, factors other than the NDVI assumed dominance in reducing sediment transport. The SCRCQ method offers a quantitative approach to assessing water–sediment changes. Based on this method, the study further underscores the substantial impacts of climate change and human activities on variations in runoff and sediment transport within the KYH_W in the middle reaches of the Yellow River. Notably, the water–sediment changes in the KYH_W exhibit distinct stage-wise and spatial discrepancies, which warrant increased attention in future research endeavors.

A meta-analysis reveals increases in soil organic carbon following the restoration and recovery of croplands in Southwest China.

In China, the Grain for Green Program (GGP) is an ambitious project to convert croplands into natural vegetation, but exactly how changes in vegetation translate into changes in soil organic carbon remains less clear. Here we conducted a meta-analysis using 734 observations to explore the effects of land recovery on soil organic carbon and nutrients in four provinces in Southwest China. Following GGP, the soil organic carbon content (SOCc) and soil organic carbon stock (SOCs) increased by 33.73% and 22.39%, respectively, compared with the surrounding croplands. Similarly, soil nitrogen increased, while phosphorus decreased. Outcomes were heterogeneous, but depended on variations in soil and environmental characteristics. Both the regional land use and cover change indicated by the landscape type transfer matrix and net primary production from 2000 to 2020 further confirmed that the GGP promoted the forest area and regional mean net primary production. Our findings suggest that the GGP could enhance soil and vegetation carbon sequestration in Southwest China and help to develop a carbon-neutral strategy.

Impact ways and their contributions to vegetation-induced runoff changes in the Loess Plateau

Study regionSixteen typical watersheds with long-term continuous runoff monitoring within the Loess Plateau (100°54′∼114°33′E, 33°43′∼41°16′N), Northwest China. Study focusFocusing on the period before and after implementing China's "Grain-for-Green" Program (GFGP) (started in 1999), this study analyzed runoff and vegetation changes and how the latter affects the former. New hydrological insights for the regionThe results show that the vegetation change effect was the main driver of runoff reduction over the LP from 1982–1999 to 2000–2015 and accounted for 78.94% (59.71–97.25%) of the reduced runoff. Changes in vegetation under multiple anthropogenic and natural influences are mainly characterized by increases in greenness, growing season length, and woodland and grassland area (along with a decrease in cultivated area). These changes have altered the repartition of precipitation in favor of evapotranspiration rather than runoff. The GFGP-led LULC shift, particularly the reduction of cropland, plays a vital role (GRD > 0.80) in vegetation-induced runoff losses, which may exacerbate future water stress in the region. To curb the LP's continuous attenuation of river runoff and promote the Yellow River Basin's ecological protection and high-quality development, we suggest focusing on the vegetation change effects on runoff and optimizing afforestation measures.

Does Participation in the “Grain for Green Program” Change the Status of Rural Men and Women? An Empirical Study of Northeast China

The Grain for Green (GfG) program is an afforestation project created by the Chinese Government to protect the environment. Farmers who participate in GfG return farmland to forest. Losing arable land means losing an income source, so farmers have to reorient their livelihood strategies, leading to potential changes in the gender division of labor. To assess gender differences in the impact of policies, we use indicators from the Women’s Empowerment in Agriculture Index (WEAI), which measures the status of women relative to that of men. Using sex-disaggregated data from farmers in mountainous areas of northeast China and applying the inverse probability weighted regression adjustment (IPWRA) estimator, we found that the status of men and women had increased with GfG participation, but women’s status had improved more than men’s. However, this was not because of their smooth participation in the program, but because of its challenges. Their decision-making skills improved unexpectedly due to pressure to protect their interests. Rural women worried about their families’ livelihoods, so they tried to improve their family welfare and diversified their income sources. In this process, women had more interactions with outside communities. Our results underline the strong need to continuously monitor the gender impacts of environmental policies.

A spatial optimal allocation method considering multi-attribute decision making and multiple BMPs random combination in sub-watersheds

Best management practices (BMPs) have been extensively employed in effective watershed management for non-point source pollution. The weights of objective functions and the restrictive conditions of combined BMPs are the vital requirements for BMPs allocation. Therefore, it is more beneficial to explore that a spatial optimal allocation method considering multi-attribute decision making and multiple BMPs random combination. Here is the novel framework based on Soil and Water Assessment Tool (SWAT) and the Non-dominated Sorting Genetic Algorithm II (NSGA-Ⅱ), which considers multiple objectives in deriving watershed-scale pollution control practices by considering BMPs cost and combined reduction rates of total nitrogen (TN) and total phosphorus (TP). The framework also integrates combined Entropy Weight method (EWM) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) to solve the weights of TN and TP, and considers the attributes of the sub-basin itself, which is more local suitability. Four categories of BMPs, tillage management, nutrient management, vegetative filter strips, and landscape management, were evaluated in the Jing River Basin (JRB) and resulted in reduction rates of 9.77%, 10.53%, 16.40%, and 14.27% averagely, respectively. BMP allocation schemes, derived from multi-objective optimization, are stratified into three financial scenarios. Low-cost scenario, costing up to 2 billion RMB, primarily targets the grain for green program in 28.81% of sub-basins. Medium-cost scenario, between 2 and 6 billion RMB, predominantly utilizes the grain for green in areas with a slope greater than 15°, accounting for 20.00% of sub-basins. High-cost scenario exceeds 6 billion RMB, mainly due to the implementation of multiple combination measures. The three configuration scenarios can provide decision-makers with a trade-off between measure costs and reduction efficiency. Overall, the innovative framework not only facilitates cost-effective implementation but provides a beneficial methodology for selecting cost-effective conservation practices in other regions.

Applying production-possibility frontier based ecosystem services trade-off to identify optimal scenarios of Grain-for-Green Program

The trade-off between grain production service (GP) and water purification service (WP) is widely acknowledged. Grain-for-Green Program (GFGP) is an effective way to alleviate ecosystem services (ESs) trade-offs and to achieve sustainable management of grain supply and water protection. However, how to identify the optimal GFGP scenario is worth further investigation. This study developed an index system for measuring ESs trade-offs, including the first-order derivative, synergy potential, and trade-off intensity based on the production-possibility frontier (PPF). Six GFGP scenarios were constructed and the non-linear trade-off between GP and WP under each scenario was evaluated. The results showed that in 2018 and six GFGP scenarios, the PPFs of the two ESs in the Dongting Lake Basin in Hunan Province showed a combination of convex-concave trade-offs. The synergy potential of GP and WP under the six scenarios increased by 2.52%~12.88%, while the trade-off intensity decreased by 6.54%~47.37% respectively, compared with the baseline of 2018. The Water Purification Priority Scenario of high-intensity was identified to be the optimal scenario with the highest synergy potential and lowest trade-off intensity, indicating that converting cropland with high nitrogen output into forest land under the condition of strict preservation of cropland could minimize the trade-off between GP and WP. This study proposed a PPF approach to identifying the optimal implementation of GFGP with the aim to realize collaborative guarantee of grain supply and water protection.

Carbon potential of China's Grain to Green Program and its contribution to the carbon target

Afforestation and reforestation are deemed promising strategies for mitigating greenhouse gas emissions and global warming. Here, we estimated the impact of China's Grain for Green Program (GFGP) on carbon storage and carbon sink capacity over the past 20 years. We then projected the carbon potential of the GFGP under expansion and management scenarios for 2030 and 2060. Our results showed that the GFGP contributed to 1482.62 Tg of a carbon sink from 2000 to 2020. By 2030 and 2060, the carbon sink induced by the GFGP reached 47.59–75.85 Tg per year, and 38.67–73.67 Tg per year, respectively. This sink offset 0.74–1.19 % and 0.98–1.87 % of the CO2 emissions from all of China in 2030 and 2060, respectively. Our results indicate that national ecological restoration programs can mitigate China's extensive carbon emissions in China, and highlight new solutions for removing CO2 from the atmosphere in other countries.

Reconsidering the eco-economic benefits of Grain for Green Program in Sichuan Province, China

The Grain for Green Program (GFGP) is an important policy implemented by the Chinese government to restore degraded forests. However, there is a limited understanding of the eco-economic benefits of GFGP in Sichuan province. In this study, the ecosystem service value (ESV) in Sichuan from 2001 to 2019 was evaluated dynamically based on the improved value equivalent method. Then, the impact of climate and human activities on ESV was explored. Finally, the eco-economic benefit model of afforestation was constructed to calculate its value efficiency in 183 counties and the return rate on afforestation investment in Sichuan. Our results indicated that the forest ESV (R2 = 0.82, P < 0.05) in Sichuan increased significantly from 2001 to 2019. Moreover, GFGP investments had a significant positive effect on forest ESV, and the correlation between afforested area and forest ESV was the highest (r = 0.88, P < 0.05). Besides, the value efficiency was relatively low in central and southwestern Sichuan, especially in and around Chengdu. In general, a total of 106 counties demonstrated low value efficiency, making up 57.92 % of the total number of counties. We also found that the return rate on GFGP investments in Sichuan was only 17.09 %. Finally, we discovered that during the consolidation phase of afforestation, 38.05 % of ESV in the core area afforested experienced degradation. Based on these findings, there is a need to encourage multistakeholder participation to jointly improve the eco-economic benefits of investing in GFGP in Sichuan now and in the future. In addition, the findings could help inform government regulators to reconsider their approach to GFGP investments and also promote more effective nature-based ecological solutions and management practices.

Climate impact greater on vegetation NPP but human enhance benefits after the Grain for Green Program in Loess Plateau

Net primary productivity (NPP) has been the subject of numerous studies, but the qualitative and comparative study on NPP that considers human activities, climate change, and their interactions is still insufficient. The Grain for Green Program (GTGP) was established in the Loess Plateau since 1999, could be used as a reference study. The temporal and spatial patterns, change trend, and driving factors of vegetation NPP were analysed in Loess Plateau using data derived from GLASS NPP (the Global Land Surface Satellite Product), meteorology, atmospheric quality, hydrology and land use by correlation and improved residual trend analysis from 2000 to 2020. After GTGP implementation, the climate and human contributions to vegetation NPP were 62 % and 38 %. NPP increased at a rate of 6.3 g C m−2 a−1 from 2000 to 2020, which was higher in 2010–2020 (6.9 g C m−2 a−1) than it was in 2000–2010 (5.7 g C m−2 a−1). The same trend was followed by the contribution of climate change to NPP between 2010 and 2020 (70.6 %) and 2000–2010 (65 %). The GTGP core area was mostly where the vegetation NPP rising zone was located. From the original bare land in the desert area, 4442 km2 of vegetation grew and increased the NPP (68.7 g C m−2). Under the warm–humid climatic trend, the climate factors contributed to NPP more in grasslands (40 %) compared to woodlands (29 %) and precipitation (33 %) was more sensitive than temperature (12.7 %). Consequently, sediment transport, PM2.5 and dusty weather decreased significantly. In conclusion, although climate change has a greater impact on vegetation, human activities have enhanced the impact faster in the first decade, which benefit and profit from the environment finally.

Regional Contribution and Attribution of the Interannual Variation of Net Primary Production in the Yellow River Basin, China

Net primary production (NPP) serves as a crucial indicator of the ecosystem’s capacity to capture atmospheric CO2. Gaining insights into the dynamics of NPP and its driving mechanisms is pivotal for optimizing ecosystem carbon sink resource management. Since the implementation of the Grain-for-Green Program (GFGP) in 1999, the Yellow River Basin (YRB) has been one of the most significant areas for ecological restoration in China. However, our knowledge regarding the interannual variability (IAV) of NPP and the underlying driving forces in this region remains incomplete. In this study, we utilized a light use efficiency model to assess the spatiotemporal dynamics, IAV, and driving factors of NPP in the YRB during the period from 1999 to 2018. Our findings revealed that the average annual NPP in the YRB approximated 189.81 Tg C. Over the study duration, NPP significantly increased in 79.63% of the basin with an overall increasing rate of 6.76 g C m−2 yr−1. The most prominent increase was observed in the key GFGP implementation area, predominantly in the semi-humid region. Notably, the middle altitude region (1–1.5 km), semi-humid region, and grassland emerged as the primary contributors to the basin’s total vegetation carbon sequestration. However, it is worth emphasizing that there was substantial IAV in the temporal trends of NPP, with the semi-humid region being the most influential contributor (62.66%) to the overall NPP IAV in the YRB. Further analysis of the driving mechanisms unveiled precipitation as the primary driver of NPP IAV in the YRB with a contribution of 62.9%, followed by temperature (23.07%) and radiation (14.03%). Overall, this study deepened our understanding of the IAV and driving mechanisms of NPP in the YRB under ecological restoration, and provided scientific support for optimizing the management of regional carbon sequestration resources.

Patterns and drivers of carbon stock change in ecological restoration regions: A case study of upper Yangtze River Basin, China

Balancing ecology and human development has been a long and wide concern. The upper Yangtze River Basin (UYRB) of China has implemented large important ecological restoration projects since the last century. These restoration practices have changed land use patterns within the UYRB, consequently impacting the local carbon cycle. The most noteworthy project is the Grain for Green Program, which returns cropland to natural vegetation (forest and grassland). Yet the effects of restoration on land use change, carbon sequestration, and associated food production remain unclear. This study utilized remote sensing data and conversion coefficients to analyze the ecological-policy-induced land use changes of the UYRB from 2000 to 2020 and their impacts on terrestrial carbon sequestration. Linear regression, machine learning, and structural equation modeling (SEM) were utilized to evaluate the correlations between environmental and socio-economic factors and the distribution of carbon stocks. The results indicated positive effects of ecological activities on the UYRB, despite decreases in cropland. Over the past 20 years, the UYRB had sequestered carbon by a total amount of 1796 ± 926 Mt C. The spatial distribution of sequestered carbon demonstrated a strong correlation with slopes, followed by temperatures. The SEM results indicated that agricultural production and carbon sequestration were enhanced synergically under land use changes. This further demonstrated the effectiveness of these land policies in achieving a balance between crop productivity and ecology protection. We emphasized the importance of vegetation restoration in achieving carbon neutrality and the necessity to continue these projects. We suggested a more reasonable land management for the future UYRB based on the characteristics of each geographical subregion. This work serves as an example of effective land management to other locations worldwide perusing the harmony of ecological restoration and human development.

Changes in soil organic carbon stocks of forestlands and grasslands on the Loess Plateau, 1980–2015

Soil organic carbon stocks (SOCS) are critical for both maintaining many ecosystem functions and regulating global climate. To address the serious soil erosion and land degradation problems on the Loess Plateau (LP), the Chinese government launched the famous “Grain for Green Program” (GGP) in 1999. However, how the SOCS change under the impacts of both GGP and climate change remains unclear. Here, we investigated the impacts of climate change and the GGP on SOCS of the top 1 m soil on the LP during 1980–2015, using a data-driven model and a multi-period land use/cover dataset. Our SOCS estimates showed that SOCS of grasslands and forestlands on the LP ranged from approximately 1400 ± 75 to 1700 ± 77 Tg C during 1980–2015. The SOCS of grasslands ranged from approximately 1000 ± 56 to 1200 ± 58 Tg C, which were roughly twice those of forestlands. Our analyses suggested that SOCS of grasslands and forestlands on the LP varied in the years before the GGP was launched in 1999, due to the continued warming and frequent drought. Unexpectedly, the SOCS did not significantly enhance after the GGP was implemented. Compared to 1995, the SOCS of grasslands and forestlands on the LP only increased on average by approximately 3.7% during 2000–2015, due mainly the adverse impact of climate change, as well as the limited effect of vegetation restoration on SOC at the early stage of the vegetation restoration programs. The study highlights the noticeably adverse effects of climate change on SOCS in the LP, providing valuable scientific support for the implementation of large-scale ecological restoration initiatives in the region.

Spatiotemporal dynamics and driving factors of soil erosion in the Beiluo River Basin, Loess Plateau, China

Soil erosion reduces soil fertility and land productivity while enhancing desertification, which seriously threatens ecological security, carbon sequestration, and sustainable economic and social development. Therefore, it is fundamental to precisely assess the long-term dynamics of soil erosion and explore its drivers to control the risk of soil erosion. Currently, machine learning-based analyses of the factors driving soil erosion are lacking in the Beiluo River Basin (BRB), China. This paper aimed to investigate the spatiotemporal dynamics of soil erosion by the Chinese soil loss equation coupled with the gully erosion factor, and then reveal its driving factors using the Boosting Regression Tree method (BRT) and estimate the influence of drivers' interactions on soil erosion in the BRB between 1990 and 2017. The findings demonstrated that the expanded Chinese soil loss equation accurately explained the variations in soil erosion in the BRB. The range of average soil erosion rates was 2,852.83–800.35 t km−2 a−1. Steep gully farmland, particularly areas with relatively rough terrain, was more vulnerable to intense erosion. Soil erosion rates for different geomorphologies decreased as follows: hilly–gully areas > gully–plateau areas > alluvial river plains > Rocky Mountains. The major drivers affecting the soil erosion rate were the biomass control factor (B) and slope, followed by slope length (L) and slope steepness (S). B–soil erodibility (1990), B–LS (2000), LS–rainfall erosivity (2010), and slope–rainfall erosivity (2017) interactions had the greatest influence on soil erosion, with interaction intensities of 32.3%, 17.75%, 46.05%, and 35.69%, respectively. The average soil erosion rates according to land classification types decreased as follows: farmland > grassland > forest. The results indicate that water and soil conservation in the study area benefited greatly from implementation of the Grain for Green Program, with forests reducing erosion more effectively than grassland.

Indigenous people's perceptions of benefits and costs of China's second phase of the grain for green program and the influencing factors

We argue that, instead of conventional monetary measures of net economic benefits, perceptions of program participants about net economic, social, environmental, and overall benefits are more important for the sustainability of the programs like the Second Phase of China's Grain for Green Program. A model of participants' perceptions of net social, economic, environmental, and overall benefits is proposed and used to examine the influencing factors of the perceptions. The model is estimated using household data from Yi (Indigenous) people of China and multivariate probit regression. Interestingly, results reveal that for both poor and non-poor participants: (i) perceived income inequality reduces the respective possibilities of perceiving positive net economic and net social benefits about the program; (ii) perceived water pollution in nearby rivers reduces the respective possibilities of perceiving positive net social and net environmental benefits; (iii) perceived increase of time for non-farm work increases the possibility of perceiving positive net economic benefit; and (iv) perceived increase of time for family care and housework increases the possibility of perceiving positive net social benefit. We suggest policy interventions to improve the influence of factors that have positive impacts on participants' perceptions and reduce the influences of factors having negative impacts.