Dou Jing-xin, Liu Jing-shuang, Wang Yang, Zhao Guang-ying
Northeast Institute of Geography and Agricultural Ecology, Chinese Academy of Sciences, Changchun.
Ying Yong Sheng Tai Xue Bao. 2008 Aug;19(8):1714-20.
A simulation study was made on the responses of biomass of Deyeuxia angustifolia and soil active carbon pool in Sanjiang Plain of Northeast China to simulated nitrogen deposition. Two water conditions (W1: non-flooded, W2: flooded) and four N treatments (equivalent to 0, 1, 3, 5 g N x m(-2) x a(-1) nitrogen deposition rate) were installed. The results showed that under effects of nitrogen deposition, the total biomass, above-ground biomass, and root biomass of D. angustifolia were higher than the control, and the increment of root biomass was the highest. Both the carbon content and its allocation proportion in D. angustifolia root increased significantly, while the carbon content in above-ground part decreased dramatically (P < 0.05). Nitrogen deposition also had significant effects on soil active carbon pools, and the contents of various fractions in the carbon pool were the highest in treatment 5 g N x m(-2) x a(-1). The responses of various fractions in soil active carbon pool to nitrogen deposition followed the sequence of carbohydrate carbon > labile carbon > dissolved organic carbon > microbial biomass carbon, and the interaction between nitrogen deposition and flooded water condition facilitated the release of soil active carbon. Regression analysis indicated that there were significant correlations between soil active carbon pools and plant indices of D. angustifolia. Nitrogen deposition could enhance the biomass of D. angustifoliat and soil active carbon content.
对中国东北三江平原小叶章生物量及土壤活性碳库对模拟氮沉降的响应进行了模拟研究。设置了两种水分条件（W1：非淹水，W2：淹水）和四种氮处理（相当于0、1、3、5 g N·m⁻²·a⁻¹的氮沉降速率）。结果表明，在氮沉降作用下，小叶章的总生物量、地上生物量和根生物量均高于对照，且根生物量的增幅最高。小叶章根中的碳含量及其分配比例均显著增加，而地上部分的碳含量则显著下降（P<0.05）。氮沉降对土壤活性碳库也有显著影响，碳库各组分含量在5 g N·m⁻²·a⁻¹处理中最高。土壤活性碳库各组分对氮沉降的响应顺序为：碳水化合物碳>活性碳>溶解有机碳>微生物生物量碳，氮沉降与淹水条件的交互作用促进了土壤活性碳的释放。回归分析表明，土壤活性碳库与小叶章的植物指标之间存在显著相关性。氮沉降可提高小叶章生物量和土壤活性碳含量。
