连续施肥对华北落叶松针叶和林地土壤生态化学计量的影响

发布时间：2018-06-12 12:04

本文选题：华北落叶松 + 生态化学计量学　；参考：《西北农林科技大学》2017年硕士论文

【摘要】：近年来,人工林面积迅速增加,但随着人工林纯林集约化的多代连栽,地力衰退问题越来越突出。导致人工林地力衰退的因素是综合的,根本原因是人类活动对人工林土壤生态系统不合理的干扰和破坏。本研究应用连续施肥手段,结合生态化学计量学理论,深入探究中林龄华北落叶松人工林(Larix principis-rupprechtii Mayr)针叶和土壤的C、N、P含量及计量比的相互关系,试图找出落叶松人工林生长发育的限制性营养元素以及探究外源N、P元素的添加对土壤肥力的改善作用,以期了解人工林生态系统的养分分布格局及其内在循环机制。结果表明:(1)、各个施肥处理对华北落叶松人工林针叶C含量影响不显著,但在不同程度上影响了针叶的N、P含量,进而影响了落叶松针叶的C、N、P计量比,特别是针叶N:P比值。除了单施磷肥外,处理N1、N2、N1P、N2P均在一定程度增加了针叶的N:P比,其中处理N1、N2、N2P下的针叶N:P显著大于对照组(CK),以处理N2P的施肥效果最优。(2)、氮磷配施(N1P、N2P)显著影响了土壤的C、N、P含量及计量比,优于其他几个处理。各施肥处理在一定程度降低了土壤C:N比值,增加了土壤C:P和N:P比值。除了施肥处理P外,土壤C:P高于我们土壤C:P的平均值,也高于全球不同生态系统土壤C:P的平均值,说明该区域土壤P缺乏。另外,施肥处理N1P和N2P下,土壤C:P与土壤P相关性不显著,说明氮磷配施对土壤P缺乏状态有一定的改善作用。各处理下,土壤C:N和N:P显著增加,且土壤C:N和N:P与N之间存在着显著相关关系,说明该区域植物生长易受N限制,施肥处理在一定程度上改善了土壤可利用N缺乏的状况。(3)、落叶松针叶和土壤的C、N、P含量及化学计量比之间不仅存在着一定的相关关系,也存在一定的差异,总体上计量比间的关联性要比养分元素高。针叶的C、N、P含量和C:N、C:P比值高于土壤的,针叶的N:P比值小于土壤的,这种差异代表了植物养分需求和土壤养分供应间的竞争和互作关系。由于C在植物体内较稳定,一般认为全球生态系统主要是通过改变的植株的N、P含量而影响C:N:P比值。
[Abstract]:In recent years, the area of plantations has increased rapidly, but with the intensive planting of pure plantations, the problem of soil fertility decline is becoming more and more serious. The factors leading to the soil fertility decline of plantation are comprehensive, and the fundamental reason is the unreasonable disturbance and destruction of soil ecosystem caused by human activities. In this study, continuous fertilization and ecochemometrics theory were used to explore the relationship between the contents of C ~ (+) N ~ (+) P in coniferous leaves of Larix principis-rupprechtii Mayr and soil, and the ratio of N ~ (2 +) to N ~ (2 +) in the middle aged larch plantation of North China (Larix principis-rupprechtii Mayr). This paper attempts to find out the limiting nutrient elements in the growth and development of Larix gmelinii plantation and to explore the effect of exogenous NbP on soil fertility in order to understand the nutrient distribution pattern and its internal circulation mechanism of plantation ecosystem. The results showed that different fertilization treatments had no significant effect on the coniferous C content of larch plantations in North China, but to some extent affected the N ~ (+) P content of needles, and then influenced the C ~ (+) N ~ (+) P ratio of larch needles, especially the N: P ratio of needles. In addition to N _ 1N _ 2N _ 2N _ 2N _ 1P _ 2P, N _ 1N _ 2N _ 2N _ 2P increased the N: P ratio of needles to a certain extent, and the N _ (1) N _ (2) N _ (2) N _ (2) N _ (2) P was significantly higher than that in the control group, so that N _ (2) N _ (2) and N _ (1) P (N _ (1) P _ (2) N _ (2) P) significantly affected the content and the metering ratio of N ~ (2 +) N ~ (2 +) P in soil. Better than the others. The ratio of C to N in soil was decreased and the ratio of C to P and N to P in soil were increased in different fertilization treatments. In addition to fertilization treatment, soil C _ (1) P was higher than the average value of soil C _ (1) P in our soil, and also higher than that of soil C _ (1) P in different ecosystems of the world, which indicated that soil P was deficient in this region. In addition, under N 1P and N 2P fertilization treatments, the correlation between soil C1P and soil P was not significant, which indicated that the combined application of N and P could improve the status of soil P deficiency to some extent. Under different treatments, soil C: n and N: P increased significantly, and there was a significant correlation between soil C: n and N: P, indicating that the growth of plants in this region was easily restricted by N. Fertilization improved the available N deficiency in soil to a certain extent. There was not only a certain correlation but also some differences between the CnP content and the stoichiometric ratio between larch needles and soil. Overall, the correlation between measurement ratios is higher than nutrient elements. The ratio of N to P in needle was higher than that in soil, and the ratio of N to P in needle was lower than that in soil. This difference represented the competition and interaction between plant nutrient demand and soil nutrient supply. Since C is more stable in plants, it is generally believed that the global ecosystem affects the ratio of C to N: P mainly by changing the content of N + P in plants.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S714

【相似文献】