【摘要】：以東北黑土區(qū)典型坡耕地(玉米)和坡林地(退耕還落葉松林和樟子松林)表層土壤為研究對象,分別在坡上、坡中上、坡中、坡中下、坡下5個坡位設(shè)置取樣點(diǎn)采集非原狀土,風(fēng)干后將土壤篩分為2~5 mm、1~2 mm、0.5~1cm、0.25~0.5 mm、0.25 mm 5個粒級團(tuán)聚體,分別計算每個粒級土壤風(fēng)干團(tuán)聚體所占比例,測定各粒級土壤風(fēng)干團(tuán)聚體有機(jī)碳含量,并以此為基礎(chǔ)計算土壤團(tuán)聚體有機(jī)碳貯量。通過對比不同坡位、各粒級風(fēng)干團(tuán)聚體組成及其有機(jī)碳含量與貯量變化規(guī)律,探明黑土區(qū)不同土地利用方式下坡地土壤團(tuán)聚體有機(jī)碳庫對不同侵蝕類型的響應(yīng)特征。結(jié)果表明:坡耕地土壤團(tuán)聚體遷移、沉積過程不同于坡林地,耕地土壤2 mm團(tuán)聚體的組成比例顯著高于2種林地,并在坡下達(dá)到最高值(70.30%);有機(jī)碳含量均隨團(tuán)聚體粒級減小逐漸增加,樟子松林地內(nèi)各粒級有機(jī)碳含量(25.57~142.60 g/kg)顯著高于耕地(22.58~30.06 g/kg)和退耕還落葉松林地(21.58~66.53 g/kg);坡林地土壤團(tuán)聚體有機(jī)碳貯量由坡上至坡下逐漸增加,相同坡位處土壤團(tuán)聚體有機(jī)碳貯量均為樟子松林地退耕還落葉松林地耕地。研究結(jié)果證實了黑土區(qū)耕作侵蝕的存在及其對土壤團(tuán)聚體、團(tuán)聚體有機(jī)碳庫分布的影響,同時印證了退耕還林是減緩坡地黑土耕作侵蝕、提升有機(jī)碳庫的長效途徑。
[Abstract]:The topsoil of typical sloping farmland (corn) and sloping forest land (returning farmland to Larix gmelinii forest and Pinus camphora forest) in Northeast black soil area was taken as the research object. The sampling points were set up at five slope positions on the slope, the middle and lower slopes, and the sampling points were set up under the slope, respectively. After air drying, the soil was divided into 2 鈮，

本文編號：2517785