江苏沿海滩涂围垦耕地质量演变趋势分析

发布时间：2018-01-26 01:19

  本文关键词： 耕地后备资源 滨海滩涂 滩涂围垦 土壤质量 江苏沿海　出处：《地理学报》2017年11期 　论文类型：期刊论文

【摘要】：淤涨型沿海滩涂作为中国重要湿地和耕地后备资源,承担着生态保护、社会保障、经济发展等多重服务功能。选取江苏中部淤涨型滨海滩涂开展实证分析,分析围垦年限为0~40年滩涂垦区耕地质量因子空间差异,采用"时空代换"方法揭示滨海滩涂围垦后耕地质量的演变趋势,为沿海滩涂围垦区耕地资源可持续利用提供决策参考。结果表明:江苏中部沿海滩涂土壤总体呈现盐碱度高、养分贫瘠等特征且土壤理化性质变异程度高,土壤质地呈现显著南北和陆海梯度特征。滩涂垦区围垦初期地形、植被状态和围垦后滨海滩涂转变为耕地路径对耕地质量演变趋势均具有重要影响。沿海滩涂转为耕地路径由垦区自然条件、开发主体、开发规模等因素共同作用,江苏中部沿海滩涂转为耕地路径已从"盐生植被→养殖水体→耕地"转变为"盐生植被→耕地",该转变缩短了滩涂转为耕地的周期,但同时也带来围垦滩涂撂荒闲置现象。围垦后沿海滩涂土壤逐步向耕地土壤转变,耕地质量因子演变趋势可分为四种:上升型,如土壤全磷、有效磷、粘粒含量;下降型,如土壤砂粒含量;下降—上升型,如有机质、全氮、碱解氮和CEC;上升—下降型,如土壤盐分和pH。围垦初期,滩涂土壤脱离海水环境,土壤有机质发生矿化过程呈现下降趋势,土壤盐分和pH受到蒸发和蒸腾作用急剧上升;围垦中期,受到人类耕作作物秸秆等有机物输入以及施肥的影响,土壤有机质、养分等呈现上升趋势,土壤盐分和pH呈现下降趋势;围垦后期,耕地质量因子受到耕作管理影响存在一定幅度的波动,由于沿海滩涂垦区耕地形成时间短,耕地质量对耕作管理等因素敏感度高。
[Abstract]:As an important reserve resource of wetland and cultivated land in China, silt tidal flat has many service functions, such as ecological protection, social security, economic development and so on. This paper analyzes the spatial differences of cultivated land quality factors in coastal reclamation areas with a reclamation period of 0 ~ 40 years, and reveals the evolution trend of cultivated land quality after coastal beach reclamation by using the method of "time and space replacement". The results showed that the soil in central Jiangsu showed high salinity, poor nutrients and high variability of soil physical and chemical properties. The soil texture showed the characteristics of north and south and land and sea gradients. Vegetation status and cultivated land path change to cultivated land after reclamation have an important impact on the trend of cultivated land quality. The coastal beach to cultivated land path from the natural conditions of reclamation area, the main development. Factors such as scale of development combined, the path of coastal beach to cultivated land has changed from "halophytic vegetation" to "halophytic vegetation" in the middle of Jiangsu Province. 鈫扖ulture water. 鈫扖onversion of cultivated land to halophytic vegetation. 鈫，

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