三江平原不同土地利用方式下沟渠沉积物可溶性有机碳含量和分布

研究了三江平原3种土地利用方式下沟渠沉积物DOC含量和分布,探讨了3种土地利用方式对沟渠沉积物DOC含量和分布的影响。结果表明,三江平原沟渠系统虽然都是在湿地的基础上开挖而成,但是分散于3种土地利用方式下的沟渠沉积物DOC含量及其分布发生了明显变化。湿地开垦为农田利于沟渠各层沉积物DOC的累积,水田和旱田相比,旱田更有利于沟渠各层沉积物DOC的累积;沟渠沉积物DOC垂直分布随土地利用方式不同发生了明显的变化,穿过型沟渠和边界沟渠相比,边界沟渠沉积物DOC垂直分布显示出更强的沉积特点。挖沟排水和土地开垦耕作,不仅导致大量DOC向沟渠迁移并沉积在沟渠中,而且最终导致不同沟渠沉积物中DOC的含量和分布产生了明显的差异性。

Study on the Content and Distribution of Sediment DOC for Ditches in Different Land-use Types in Sanjiang Plain

Collecting Sediments of ditches in three land-use types in order to measure the content of dissolved organic carbon (DOC),we researched on the content and distribution of sediment DOC under three land-use types in Sanjiang Plain.Furthermore,we discussed the influence of three land-use types on sediment DOC. The findings indicated that the content and distribution of sediment DOC changed obviously with changing of land use type in Sanjiang Plain,though they were excavated for drainage on the wetlands.The wetland was reclaimed for the farmland,which benefited the accumulation of sediment DOC for ditches,at the same time, compared with paddy field,the dry land was favorable to the accumulation of per layer of sediment DOC for ditches;The vertical distribution of sediment DOC for ditches obviously changed in three land use types, what's more,compared with thread-type ditches,the vertical distribution of sediment DOC in edge-type dit- ches demonstrated better characteristics of deposition;The land cultivation and drainage were the main cause of the different content and distribution of sediment DOC in all kinds of ditches.The land cultivation and drainage not only led to transference and sedimentation of DOC,but also the difference of sediment DOC con- tent and distribution in the ditches.