摘要: |
[目的]客观科学地评价退耕还林工程对县域耕地压力效应的影响。[方法]文章以乌江流域典型县——武隆县为例,通过实际调查和运用耕地压力指数模型来分析退耕还林工程对耕地压力效应的影响。[结果]近15年来,退耕还林工程面积与农村剩余劳动力转移相关性R2=0.9342;研究区退耕还经济林方式下存在林下种植现象,其产生的“实际”人均耕地面积为0.204hm2/人,比正常人均耕地面积0.164hm2/人增加了0.04hm2/人;研究区粮食总产量受到退耕还林工程的影响甚微,但退耕粮食补贴占粮食总产量比例随退耕面积逐渐增大而增大,且处于2.6%~20.9%之间,平均为17.2%;退耕粮食补贴在减缓区域耕地压力状态比退耕转移农村剩余劳动力和林下种植方式下明显,但人均粮食占有量的提高会极大地增加区域的耕地压力状态。[结论]总体上,退耕对县域耕地压力效应具有正效应,对客观地总结评价以及深化退耕还林工程,有序推进新一轮退耕还林工程规划设计具有重要理论和实践指导意义。 |
关键词: 渝东南生态保护区 耕地压力指数 粮食安全 平衡 退耕还林工程 |
DOI: |
分类号:F326 |
基金项目:重庆市教委人文社科项目“退耕还林工程对县域社会经济影响研究”(15SKG261);国家自然基金项目“黄土高原森林草原过渡带辽东栎林土壤呼吸及碳收支”(41201258) |
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EFFECTS OF LAND CONVERSION PROJECTS ON THE LAND PRESSURE——TAKING WULONG COUNTY AS A CASE |
Cheng Liusan1, Shi Weiyu2
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1.School of Geology Engineering Geomatics in Chongqing Institute of Engineering, Chongqing, 402260, China;2.Chongqing Key Laboratory of Karst Environment, School of Geographical Sciences, Southwest University, Chongqing 400715, China
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Abstract: |
In order to scientifically and objectively assess the influences of the conversion of cropland to forest projects on land pressure, this paper chose a representative county of Wulong in the basin of the Wujiang river as a case, and studied the influence of the conversion of cropland to forest projects based a field investigation and using land pressure indexes model. The results showed that: in recent 15 years, the correlation was R2=0.9342 between the areas of conversion of cropland to forest and transferring of rural surplus labor. Due to the cultivated crops under forest, the per capita area of the "actual" cultivated farmland was 0.204hm2/person, contrasted to the "normal" with 0.164hm2/person, with an increase of 0.04hm2/person. The conversion of cropland to forest projects had little effect on the total grain outputs in Wulong. The area with the ratio of grain subsidy accounting for the total grain outputs increased along with areas of the sloping land conversion program/grain for green project, which ranged from 2.6% to 20.9%, with an average value of 17.2%. Grain subsidy of the conversion of cropland to forest can obviously slow down the regions of land pressures compared to transferring of rural surplus labor and tree-crop models, but the increase of the per capita grain would add greatly the regions of land pressures. As a whole, the conversion of cropland to forest projects had positive influence on regions of land pressure. The results had important theory value and practice direction for designing and planning the land conversion projects. |
Key words: ecological protection area in Southeast Chongqing pressure index of cultivated land food security balance conversion of cropland to forest projects |