南湖新闻网讯（通讯员 王彦博 扈晓碟） 近日，我校水土流失过程与生态调控创新团队在坡耕地水土保持研究方面取得进展，并在Earth-Science Reviews发表了题为“Soil conservation of sloping farmland in China: History, present, and future”的学术论文。
我国山丘区面积大、坡耕地分布广，现有坡耕地4.4亿亩，占总耕地面积的22.74%，是我国山丘区群众赖以生存的土地，而坡耕地是我国水土流失的重要策源地，关系到国家生态安全和粮食安全。为应对坡耕地水土流失，我国人民在长期历史发展中创造了截水沟（公元前1066-476年）、垄沟耕作（公元前475-221 年）、区田（公元前202-8 年）等水土保持措施；近几十年来我国政府先后实施了退耕还林、小流域综合治理、坡耕地水土流失治理等系列工程，有效遏制了坡耕地水土流失持续恶化的趋势。然而，迄今为止，我国坡耕地水土保持措施的历史及其效果尚未得到全面评价。
研究团队通过历史资料整理和文献荟萃分析，回顾了2500年前至今中国坡耕地水土保持措施的发展历程，梳理了1980年以来水土流失治理重大事件，并基于6909个径流小区观测数据，揭示了水土保持措施在当前和未来气候变化情景（SSP1、SSP2、SSP5）下的有效性。结果表明：目前水土保持措施平均可减少坡耕地51%的径流和80%的土壤流失，其中生物和工程措施相结合的水土保持效果最好。然而，受气候变化的影响，预计2050年近1/3坡耕地上的水土保持措施效果下降，威胁我国生态安全和粮食安全。建议未来积极整合资源，以水为纽带、生态措施为主、辅以工程措施，统筹山水田林路，提升生态功能。成果可为中国坡耕地水土保持措施的布局、管理和维护提供科学依据。
我校博士研究生王彦博、扈晓碟为论文的共同第一作者，史志华教授、王玲副教授为论文通讯作者。我校于书霞副教授、王真教授、赵劲松副教授、肖海兵副教授和中国科学院水利部水土保持研究所方怒放研究员参与了研究。本研究得到了国家自然科学基金项目的资助。
【英文摘要】
In China, sloping farmland accounts for one-third of its total farmland, supporting ~330 million mountain people's livelihoods. Despite its long history of using soil conservation measures for reducing soil loss on sloping farmland, no comprehensive evaluation has ever been performed on their effectiveness. In this study, we reviewed the soil conservation measures on sloping farmland in China from ~2500 years ago to the present and examined their effectiveness under current and projected climate change scenarios based on 6909 plot-scale observations. For the sloping farmland across China, the average soil loss rate is 14.47 Mg ha−1 yr−1, with a quarter of the observed values exceeding the maximum tolerable soil loss rate (10 Mg ha−1 yr−1). Soil conservation measures can reduce soil loss by ~80%, with the highest effectiveness for the combination of biological and engineering measures (reduced by ~86%), followed by biological measures (reduced by ~84%) and engineering measures (reduced by ~82%) separately. However, the effectiveness of soil conservation measures shows a significant decrease in the farmland with a slope above 15° or a single rainfall event >25 mm. The effectiveness of currently applied soil conservation measures was also compared under the Shared Socioeconomic Pathways (SSP) 1, 2, and 5 in 2050, and their effectiveness is expected to decrease on over 27% of the sloping farmland. In particular, under the SSP1 scenario, the effectiveness of soil conservation measures is projected to diminish in 70%, 54%, and 54% of sloping farmland in Northeast China, Sichuan Basin and surrounding regions, and Yunnan-Guizhou Plateau, respectively, due to changes in rainfall, highlighting the need to consider the impact of climate change when implementing soil conservation measures. Overall, this study provides useful information for scientific strategies on the construction, management, and maintenance of soil conservation measures to control soil loss on sloping farmland.
审核人：史志华
