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Desertification is among the most severe global environmental and the socio-economic problems in the world. This paper is a first attempt to link scientific research to national policymaking on desertification in China. We aim to trace scientific research findings in the national policies and strategies of desertification prevention in China. One example is the large-scale plantation programme in the dust source region threatening Beijing and Tianjin since 1998. It has been suggested that the recent increased forest cover due to plantations in North China has helped reduce dust storm emissions and contributed to mitigating dust storm weather in Beijing and Tianjin. Reforestation/afforestation policy remains in the Chinese national environmental strategies for the new national forestation programme (2011-2020). Overgrazing during recent decades has been blamed for land degradation and desertification in Northwest China by many scholars. Small field experiments prove that vegetation in desertified/degraded land could recover if isolated from human activities. Since 1998, natural recovery has become one powerful national force to prevent land desertification and recover natural vegetation. One example is selected at Cele County, Xinjiang Uygur Autonomous Region to showcase how vegetation could thrive at large scale in natural arid and semi-arid climate if isolated from human intervention. The plantation project has pushed the stakeholders to better understand their negative impact on the environment, especially the overgrazing behaviour. After that, the household income and living level have also been significantly enhanced; however, it is not clear whether the project induced labour migration. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: The Loess Plateau experiences the most serious soil erosion problems in China and possibly even globally. Many measures have been taken to increase the vegetation cover and to control soil erosion. Of these measures, the Grain for Green Project, launched in 1999, has been the most effective, changing the ecological and socio‐economic situation of the Plateau significantly. Using time series normalized difference vegetation index (NDVI) data from 1981 to 2013, this study analysed spatial patterns of changes in vegetation cover, detected spatial patterns of the abrupt‐change time of NDVI trends, and investigated factors that may contribute to these changes. The results showed that (a) vegetation restoration was obvious over the last decades, especially in the 2000s, and the increase in NDVI during 2000–2013 was more than 3‐times that during 1990–2000. Approximately 54.99% of the Plateau during 2000–2013 had a statistically significant increase, mainly distributing in loess hilly and gully region and loess gully region. (b) Vegetation restoration was comprehensively affected by climate change and human activities (e.g., the Grain for Green Project, urbanization and policies), and the effects of each factor varied for different regions. (c) Vegetation in most of the Plateau began to increase around 2007–2010, and 4 discrete areas with different timings of such break points were detected. The difference in the timing of break points in NDVI may be related with precipitation, reproducing tree species, management measures, and survival rate. These results imply that integrating natural and human factors is important when making effective and suitable measures and policies. [ABSTRACT FROM AUTHOR]

Sand desertification is a serious ecological and environmental problem in semiarid grassland areas; thus an accurate understanding of its causes and process mechanisms is of significance for grassland desertification control. With the popularization of remote sensing monitoring technology, most research has focused on analyzing the trends of grassland sand patches and their impact on regional desertification, whereas fewer studies have explored the mechanisms of grassland desertification development. This study analyzed the dynamic changes in grassland landscape in the Hulun Buir grassland of China via multiperiod high‐resolution remote sensing images from 1959 to 2020, and examined the morphological changes, erosion patterns, grain size characteristics and sediment compaction of two trough blowouts. Our study noted that under climate change and human activities, grassland desertification is becoming increasingly serious, and its main manifestation is the occurrence and expansion of blowouts. Changes in blowout morphologies indicate that the area of the deflation basin shows a state of continuous growth, whereas the area of the depositional lobe shows fluctuating changes, which could mean that the deflation basin may be a useful indicator of desertification. Based on a detailed analysis of both climate and grassland changes, we believe that human activities determine the occurrence of blowouts, and climatic conditions determine the expansion of blowouts and the desertification degree. The morphological changes of blowouts are related to the removal mode and erosion resistance of the grassland soil, and the rate of removal of the soil limits the rate of blowout expansion. [ABSTRACT FROM AUTHOR]

The arable‐pastoral ecotone in northern China is ecologically fragile and the region has experienced substantial climatic variability, triggering population migrations, and the alternation of subsistence strategies during the historical period. However, the lack of continuous proxy records of arable and grazing activity has hampered our understanding of shifts in subsistence strategies and their relationship with climatic and societal changes. We obtained records of Sporormiella‐type spores and crop pollen from Gonghai Lake in northern China to reconstruct changes in cultivation and grazing intensity over the past approximately 2000 years. The results show that intensive grazing and cultivation occurred during the Sui and early‐middle Tang Dynasties (581–820 CE), when there was a relatively favourable climate, harmonious ethnic relations, and strong central government control. Conversely, weakened agricultural activity in the late Tang Dynasty (820–907 CE) corresponded to a deteriorating climate and frequent wars. High temperatures during the northern Song Dynasty (960–1127 CE) promoted the expansion of arable land in mountainous areas, whereas a cold climate and societal crises during the Era of Disunity (220–580 CE) and the Ming‐Qing Dynasties (1368–1912 CE) limited the expansion of cultivated land and there was a shift to grazing as a subsistence activity. Time‐series analysis reveals that the arable farming phases had a longer periodicity than the grazing phases, possibly because of the greater resilience of the former to climate change and the attachment of agriculturalists to their land. Our findings potentially help improve our understanding of the impact of land use on soil degradation. [ABSTRACT FROM AUTHOR]

The Tibetan Plateau experienced severe aeolian desertification during the mid‐ and late 20th century, but mitigation of this aeolian desertification has occurred since 2000 despite a warming climate. The causes of aeolian desertiffication and its mitigation have been debated by scientists because of their potentially huge significance for PR China and Asia, as well as for global climate systems. Based on a review of previous studies and our own investigations, it appears that aeolian desertification from the 1970s to 2000 was caused primarily by unsustainable and irrational human activities, and its mitigation since the 2000 was mainly attributable to a warmer and wetter climate, combined with decreasing wind intensity, for the Plateau as a whole. However, the dominant factors for mitigation varied spatially. The Government's ecological protection projects have been implemented in some places with dense population, and played a key role in the mitigation in these places. The Plateau's climate will likely become warmer and wetter in the 21st century based on Coupled Model Intercomparison Project Phase 5 model simulations. If the simulation results are credible, mitigation of aeolian desertification will continue in the 21st century due to a combination of continuing grazing exclusion and rotational grazing, even without artificial revegetation. [ABSTRACT FROM AUTHOR]

To reduce the damage caused by wind erosion, the accurate evaluation of wind erosion dynamics and revelation of their driving mechanism are crucial. In this study, the revised wind erosion equation was applied for the estimation of the potential wind erosion rate (PWER) from 1982 to 2015 in the Hexi region, China. Geographic detection, variable control, and correlation analysis were used to determine the contributions of climatic factors and land use patterns to wind erosion. The results showed that the PWER decreased remarkably from 1982 to 2015 (annual average of 67.7 t ha−1 yr−1 for the entire region). Each year a severe and a mild wind erosion period occurred from October to May and from June to September, respectively. Spatially, the PWER was strong in the eastern, western, and northern regions (especially in the west) and less severe in the central and southern regions, and there was a decreasing tendency in 95% of the area. The PWER of Mongolia (north) was highest, while that of Minle was lowest. Climatic factors primarily determined the PWER in Hexi, among which wind speed was the main factor controlling the intensity of wind erosion. The area with a land use inhibiting wind erosion (3,240 km2) was four times larger than that with a land use promoting wind erosion (800 km2). Meanwhile, the total area with a changing land cover was less than 2% of the study area; therefore, this factor did not significantly affect the PWER in the short term. [ABSTRACT FROM AUTHOR]

Terrestrial ecosystem productivity (TEP) is an important component of ecological services. The variability of the TEP is driven by multiple factors, both natural and anthropogenic. However, little is known about the dominant factor driving the TEP change at the pixel level, which may hinder ecosystem management particularly in face of global climate changes. In this study, a 22‐year‐long dataset including climate, net primary production (NPP), and human activity was obtained to identify, at a pixel level, the dominant factors of NPP variation in China from 1992 to 2013. The results showed that: (a) the total NPP of China varied from 3.37 to 4.55 PgC/yr and continued to increase with a larger proportion being contributed from eastern China, (b) radiation is the greatest contributor to the NPP variation in China, followed by temperature and precipitation, (c) human activity‐driven pixels are relatively dispersed, and are mainly located in the rural–urban fringe zones, and (d) a total of five subregions are identified, of which Regions I and II require more attention with regard to future NPP evolution. The results of this study are important at the policy level for future management of China's ecosystems. [ABSTRACT FROM AUTHOR]

In agro‐ecosystems, fertilization practices must accomplish high and stable crop productivity, with maximum soil organic carbon (SOC) sequestration to address climate change and food security challenges. However, the impacts of these practices on SOC and crop yields are variable over the long‐term duration, and an improved understanding of the factors influencing SOC sequestration and sustainable productivity is still needed to provide evidence‐based management decisions. Therefore, we conducted a meta‐analysis to evaluate the impact of long‐term (≥10 years) application of different fertilizer management practices adapted across China on crop productivity, yield sustainability, and SOC sequestration. Results indicated that unbalanced mineral fertilizer (UMF), balanced mineral fertilizer (BMF), organic fertilizers (OF), combined unbalanced mineral and OF, and combined balanced mineral and organic fertilizers (BMOF) significantly enhanced the grain yield, and SOC sequestration compared with control (p <.05). For UMF, the increases in SOC and grain yields were least among fertilization practices. Comparing OF, BMF mostly produced more grain yields, but with a slight increase in C sequestration. Highest SOC sequestration rate of 0.43 Mg C ha−1 yr−1 was recorded in BMOF, among all the treatments. The data obtained indicated that SOC sequestration is highly time‐dependent. Irrespective of fertilization mode, SOC gradually increased and attained the peak of sequestration rate in the initial two decades rather than at later stages of fertilizer addition. The linear fitted model indicated that an increase in SOC sequestration benefits sustainable productivity. The available data indicate that crop yields can be improved by 143 kg ha−1 for rice (Oryza sativa), 255 kg ha−1 for maize (Zea mays), and 202 kg ha−1 for wheat (Triticum aestivum) with every 1 Mg ha−1 increase in SOC stock by fertilization in the root zone. In crux, BMOF can maintain and improve soil quality while producing high and stable crop yields. [ABSTRACT FROM AUTHOR]

Desertification of arid and semiarid land is a severe environmental problem. Better understanding of the desertification process, in the context of changing climate and growing human activities, is essential for policy-making on desertification control strategies and land-use management in these environmentally sensitive areas. In this study, we analyze vegetation change and dune activity over the years 1981-2013 in Mu Us, a semiarid dune field in north-central China, using remote sensing techniques and geomorphic analysis. During this period, we have observed an increasing trend in vegetation greenness, indicated by the Normalized Difference Vegetation Index, which is consistent with the decreasing trend of the dune mobility index. Changes in dune morphologies in the study area indicate that dunes are being stabilized under vegetation growth, and this morphological change could potentially be used to detect the long-term trend in desertification. Based on a detailed analysis of both climatic and socioeconomic data, we found that the decadal changes in wind strength have significant impact on the long-term vegetation rehabilitation in the study area and that the short-term variations in vegetation growth are associated with interannual fluctuations in precipitation. Policy-driven, large ecological restoration projects implemented in recent decades can exert a positive impact on vegetation restoration, especially under favourable climatic conditions. This study implies that such climatic conditions may offer a window of opportunity for land regeneration in semiarid northern China. [ABSTRACT FROM AUTHOR]

Abstract: A preliminary conceptual framework is proposed for the estimation of the costs of desertification. This framework consists of assessment of the extent and severity of desertification, identification of various impacts and valuation of the direct and indirect costs of desertification. Based on this framework, three well‐cited studies of the costs of desertification in China were critically reviewed. Limitations in these studies include double counting, confusion of short‐term and long‐term costs and the lack of necessary adjustment of price parameters. Refinement of the estimates indicates that these limitations have caused serious overestimation or underestimation of the costs of desertification. To achieve more reliable and useful estimates, future studies need to overcome the limitations mentioned in the preceding texts and use the latest available data on desertification and its various impacts. A more comprehensive conceptual framework that includes the valuation of dryland ecosystem services could also be developed to guide future studies. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT Impacts of land use and climate change on runoff were investigated by studying the runoff in the Yarlung Zangbo River basin, China. Trends in precipitation, mean air temperature, and runoff were analysed by non-parametric Mann-Kendall tests. Land-use changes were examined with land-use transition matrix and geographic information system tools. Land-use and climate changes showed several characteristics, including increased reforestation, decreased grassland, retreat of glaciers and increased desertification. Human activity caused great impact, especially within densely populated regions and cities. Reforestation and degradation of grasslands were more frequent than deforestation and cultivation of grasslands. Annual mean air temperature, precipitation and runoff showed increasing trends between 1974 and 2000. The impacts of land use and climate change on runoff had different effects depending on region and season. In the season of freezing, climate change clearly affected runoff within regions that experienced precipitation. Altered evapotranspiration accounted for about 80 per cent of runoff changes, whereas land-use changes appear to have had greatest impact on runoff changes within regions that have inconsistent relationships between runoff and climate change. It was demonstrated that afforestation leads to increased runoff in dry seasons. It was estimated that glacier snow melt has caused annual runoff to increase at least 6·0 mm/10yr, 2·1 mm/10yr and 1·7 mm/10yr in Regions 1, 3 and 4, respectively, whereas evapotranspiration caused annual runoff to decrease at least 7·4 mm/10yr in Region 2. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The article discusses a study on the effect of land use/cover change (LUCC) on Lake Qinghai Watershed on the northeastern margin of the Qinghai-Tibet Plateau. Noted is the vulnerability and sensitivity of the lake's ecosystem to climate change and human interference. Through the use of geographical information system (GIS) and remote sensing (RS), the researchers were able to analyze LUCC pattern in the watershed between 1977 and 2004. Based on the analysis, the watershed is dominated by grassland and water body. It also revealed that LUCC magnitude in the watershed is low.

The article presents a historical review of the environmental conditions leading to the desertification of Western Hainan Sheng, China. An analysis of the ecology of the region from 1959 to 2003 is presented, highlighting the multiple factors causing soil degradation. Several analytical methods are utilized including remote sensing, geographic information system (GIS) analysis, and statistical analysis of human and climatic elements. A progression of desertification, remediation, and ecological flux is presented, suggesting that both human and natural factors are responsible for the phenomena.