地理学报 ›› 2017, Vol. 72 ›› Issue (11): 2032-2046.doi: 10.11821/dlxb201711009

• 地表过程与生态环境 • 上一篇    下一篇

江苏沿海滩涂围垦耕地质量演变趋势分析

许艳1,2,3(), 濮励杰1,2(), 张润森1, 朱明1,2, 李雪盈1, 沈洪运1, 茅天颖1, 徐辰星1   

  1. 1. 南京大学地理与海洋科学学院,南京 210023
    2. 国土资源部海岸带开发与保护重点实验室,南京 210023
    3. 苏州科技大学环境科学与工程学院,苏州 215009
  • 收稿日期:2017-04-10 修回日期:2017-08-08 出版日期:2017-11-20 发布日期:2017-11-16
  • 作者简介:

    作者简介:许艳(1986-), 女, 江苏滨海人, 博士后, 主要从事土地利用与规划研究。E-mail: xuyanxiaozz@126.com

  • 基金资助:
    国家自然科学基金重点项目(41230751);江苏省博士后科研资助计划(1601067B)

Cropland quality evolution following coastal reclamation at the prograding tidal flats of Jiangsu Province, China

Yan XU1,2,3(), Lijie PU1,2(), Runsen ZHANG1, Ming ZHU1,2, Xueying LI1, Hongyun SHEN1, Tianying MAO1, Chenxing XU1   

  1. 1. School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210023, China
    2. The Key Laboratory of the Coastal Zone Exploitation and Protection, Ministry of Land and Resources, Nanjing 210023, China
    3. School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, Jiangsu, China
  • Received:2017-04-10 Revised:2017-08-08 Online:2017-11-20 Published:2017-11-16
  • Supported by:
    National Natural Science Foundation of China, No.41230751;Postdoctoral Program of Jiangsu Province, No.1601067B

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。

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

Abstract:

Coastal prograding tidal flats are important wetlands and reserve resources of cropland in China, which provide the services of ecological protection, society security, and economic development. Taking the reclamation zones on the prograding coast of Jiangsu as a case study, this paper analyzed soil quality at the reclamation zones with a duration of 0-40 years to indicate the evolution of cropland quality following reclamation for sustainable use of cropland, by using the method of "space for time substitution". The results show that cropland soils had high salinity but low nutrients. The variation of soil physical and chemical properties is high in the coastal reclamation zones, and the soil particle sizes had obvious gradients of North-South and Land-Sea. The factors such as topography, vegetation status, and the path of tidal flats to cropland had significant impacts on cropland quality evolution following coastal reclamation. The path of tidal flats to cropland were jointly decided by physical condition of reclamation zones, development entity, and development scale in the coastal area of Jiangsu. The cropland trajectories have changed from "halophytes→aquaculture pond→cropland" to "halophytes→cropland" in the central part of the province's coastal area. This change shortened the period of tidal flats to cropland, but led to idle tidal flats after reclamation. The soils of coastal tidal flats have gradually transferred into soils of cropland. The changing trends of soil properties were divided into four types. The first one was the type of increase, such as soil total phosphorous, available phosphorous, and clay content. The second one was the type of decrease, such as sand content. The third one was the type of increase then decrease, such as soil salinity and pH. The fourth one was the type of decrease then increase, such as soil organic matter, total nitrogen, available nitrogen, and capacity of exchange cations. At the initial period of reclamation, soil organic matter showed a declining trend because of the process of mineralization. The soil salinity and pH increased due to transpiration and evaporation. At the middle period of reclamation, soil organic matter and nutrients increased because of the fertilization and organic matter input via human cultivation. Soil salinity and pH decreased as a result of precipitation and water resource facilities. At the later period of reclamation, the factors of soil quality fluctuated under the effect of cultivation management. The quality of cropland at the reclamation zones was fragile and sensible to cultivation management, because of the relatively short history of coastal reclamation.

Key words: reserve resources of cropland, coastal tidal flat, reclamation of tidal flat, soil quality, Jiangsu coast