机构地区:[1]西北农林科技大学水土保持研究所,陕西杨凌712100 [2]中国科学院水利部水土保持研究所,陕西杨凌712100 [3]延安市退耕还林工程管理办公室,陕西延安716000 [4]延安市林业局,陕西延安716000 [5]延安市天然林资源保护工程管理办公室,陕西延安716000
出 处:《水土保持研究》2023年第1期209-215,共7页Research of Soil and Water Conservation
基 金:国家自然科学基金(41771556);国家重点研发计划课程(2016YFC0501703);陕西省水保研发项目(2017sbkj-01)。
摘 要:为明析“退耕还林草”政策实施以来延安市各区县实施效果,基于统计年鉴数据,以1999—2018年延安市退耕还林草植被恢复概况为基础,分类汇总各区县退耕还林草面积(退耕还林、封山育林和荒山造林)、乔灌草分布和生态经济比例,总结该区退耕还林草工程实施效果,剖析其存在问题,建立适宜当地退耕还林草发展的综合治理模式,以期为后续退耕还林草工程实施提供理论参考。结果表明:(1)截至2018年,延安市累计完成退耕还林草面积71.82万hm^(2),主要在吴起县(13.78万hm^(2))、安塞区(9.48万hm^(2))和志丹县(9.04万hm^(2))最高,其中退耕还林面积最大(44.18万hm^(2)),其次为荒山造林(26.02万hm^(2)),封山育林最少(1.63万hm^(2));(2)植被覆盖度整体随时间显著增加(p<0.01),决定系数R2=0.87,主要分布在黄龙县(90.5%)、黄陵县(89.7%)和富县(86.7%),延川县、子长县和吴起县最低,分别为68.7%,68.3%和66.7%;(3)乔木林、灌木林和草本植物面积分别为46.81万hm^(2),25.01万hm^(2),0.01万hm^(2),乔灌比在黄龙县(87∶1)、延川县(39∶1)、黄陵县(38∶1)和宝塔区(16∶1)较大,而草本植物仅在甘泉县涉及,面积为0.01万hm^(2);(4)生态林主要以刺槐和沙棘为主,面积占比分别为34.43%和20.70%,生态经济林为苹果和山杏,占总退耕还林草面积的2.96%和4.42%;(5)生态经济林面积占比在子长县、安塞区、洛川县和志丹县较高,比例分别为51∶1,27∶1,24∶1,18∶1。综合来看,延安市各区县退耕还林草的实施对当地生态环境具有显著促进作用,但相关部门还需进一步改善植被覆盖度、乔灌草和生态经济林比例,并加强对退耕还林草的管护。To analyze the implementation effect of the ‘Returning Farmland to Forestland and Grassland’ policy clearly in all districts and counties of Yan′an City, based on the statistical yearbook data, we analyzed the effect of vegetation restoration of the project of returning farmland to forestland(grassland) in Yan′an City from 1999 to 2018, and established a comprehensive development model suitable for the project of returning farmland to forestland(grassland) in Yan′an City in order to provide theoretical reference for the follow-up implementation. Based on the effectiveness of vegetation restoration in Yan′an City, we analyzed the area of conversion of farmland to forestland and grassland(returning farmland to forestland, closing hills for afforestation and afforestation), the proportion of trees, shrubs and grass, and the ecological economy, and comprehensive analyzed the forest and grass project implementation results and existing problems in Yan′an City. The results show that:(1) until 2018, Yan′an City had completed the conversion of farmland to forestland(grassland) with an area of 718 200 hm^(2), which mainly concentrated in Wuqi County(137 800 hm^(2)), Ansai County(94 800 hm^(2)) and Zhidan County(90 400 hm^(2));the area of returning farmland to forestlan and grassland was the largest(441.8 thousand hm^(2)), followed by barren mountain afforestation(260 200 hm^(2)), and the area of closing hills for afforestation was the least(16 300 hm^(2));(2) the overall vegetation coverage in Yan′an City had increased significantly over time(p<0.01, R~2=0.87), the higher vegetation coverage was found mainly in Huanglong County(90.5%), Huangling County(89.7%) and Fu County(86.7%), the vegetation coverage of Yanchuan County, Zichang County, and Wuqi County was the lowest, which was 68.7%, 68.3% and 66.7%, respectively;(3) the areas of arbor forest, shrub forest and herb forest were 468 100 hm^(2), 250 100 hm^(2) and 0.01 million hm^(2), respectively;the ratios of arbor forest to shrub forest were 87∶1 i
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