塔里木沙漠公路防护林地表凋落物分解对施肥的响应

发布时间：2018-08-09 11:55

【摘要】：为探讨沙漠公路防护林地表凋落物的分解速率和养分释放动态对施肥的响应,采用凋落物分解袋法,对塔里木沙漠公路防护林地乔木状沙拐枣(Calligonum arborescens)同化枝、梭梭(Haloxylon ammodendron)同化枝和多枝柽柳(Tamarix ramosissima)枝凋落物在施肥处理下的分解及养分释放特征进行研究。结果表明:经过420d的分解,3种凋落物质量残留率在对照(不施肥)、施用氮肥、施用磷钾复合肥处理间存在显著性差异(P0.05)。乔木状沙拐枣同化枝、梭梭同化枝和多枝柽柳枝在对照处理下的质量残留率分别为56.95%、31.32%和50.24%。施肥处理下3种凋落物均呈现出梭梭同化枝分解速率最快,多枝柽柳枝次之,乔木状沙拐枣同化枝分解最慢。施用磷钾复合肥极显著提高了3种凋落物的分解速率(P0.01);施用氮肥则促进多枝柽柳枝的分解,抑制乔木状沙拐枣和梭梭同化枝的分解。凋落物分解过程中,对照组3种植物凋落物的C、N、P和K元素均呈现净释放状态;施肥后凋落物的N、P和K元素呈现出富集-释放的模式。凋落物初始P含量和C/N、C/P比值是分解初期的主导因素,初始K、木质素、纤维素含量和C/N、木质素/N比值是分解后期的主要控制因素。研究表明,施肥显著影响沙漠公路防护林地表凋落物的分解,增加防护林地表凋落物的养分归还量,延后养分释放的时间,改善塔里木沙漠公路防护林地的土壤肥力。凋落物初始C/N比值是预测塔里木沙漠凋落物分解的重要因素,且不同分解时期影响凋落物分解的初始化学组成有所差异。
[Abstract]:In order to study the decomposition rate of surface litter and the response of nutrient release dynamics to fertilization in desert highway shelter forest, the (Calligonum arborescens) assimilation branch of Arbor Elaeagnus angustifolia in Tarim Desert Highway Shelter Forest was studied by litter decomposition bag method. The characteristics of decomposition and nutrient release of (Haloxylon ammodendron) assimilated branches and (Tamarix ramosissima) branches of Tamarix chinensis were studied under fertilization. The results showed that after 420 days of decomposition, there were significant differences among the treatments of control (no fertilization), application of nitrogen fertilizer and compound fertilizer of phosphorus and potassium (P0.05). The residual rates of assimilation branches of Arbor, Haloxylon ammodendron and Tamarix chinensis were 56.95% and 50.24%, respectively. Under fertilization treatment, the decomposition rate of the assimilated branches of Haloxylon ammodendron was the fastest, followed by the branches of Tamarix chinensis, and the assimilation branch of Arbor was the slowest. The application of phosphorus and potassium fertilizer increased the decomposition rate of three litter species (P0.01), and the application of nitrogen fertilizer promoted the decomposition of Tamarix chinensis branches and inhibited the decomposition of the assimilating branches of Arbor Jujube and Haloxylon ammodendron. In the process of litter decomposition, the C ~ (+) N ~ (+) P and K elements of the three plant litters in the control group showed a net release state, while the N _ (+) P and K elements in the litter showed a pattern of enrichment and release after fertilization. The initial P content and C / N / P ratio of litter were the dominant factors in the early stage of decomposition, while the initial K, lignin, cellulose content and C / N, lignin / N ratio were the main controlling factors in the later stage of decomposition. The results showed that fertilization significantly affected the decomposition of litter, increased the amount of nutrient return, delayed the release of nutrients, and improved the soil fertility of shelterbelt on Tarim desert highway. The initial C / N ratio of litter is an important factor in predicting litter decomposition in Tarim desert, and the initial chemical composition of litter decomposition is different in different decomposition periods.
【作者单位】：中国科学院新疆生态与地理研究所;新疆大学资源与环境科学学院;中国科学院大学;国家荒漠-绿洲生态建设工程技术研究中心;
【基金】：国家自然科学基金项目(41271341,41030530,41301038) 塔里木油田公司项目(971012080007) 水利公益性行业科研专项(201401049)
【分类号】：S714

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