兰州大学机构库 >生命科学学院
柽柳肥岛效应对土壤氮矿化及硝化速率的影响
Alternative TitleEffects of fertile island on the rates of soil nitrogen mineralization and nitrification under Tamarix plant
张书亭
Thesis Advisor徐世健
2017-05-05
Degree Grantor兰州大学
Place of Conferral兰州
Degree Name硕士
Keyword盐渍化 肥岛效应 酶活性 氮矿化速率 氮硝化速率
Abstract

盐渍化是当前世界范围内所面临严重的环境问题,其不仅影响当地居民的生存和发展,还威胁着整个区域内的生态安全。因此,系统研究荒漠盐渍化环境中植物对土壤的作用机制,对于盐渍化土地的改良、防治具有重要的意义。目前,盐渍化土壤的改良途径主要有物理、化学和生物改良法,应用较为广泛的是生物改良法。本研究以甘肃河西走廊西部疏勒河下游不同程度盐渍化区域的多枝柽柳(Tamarix ramosissima)相关土壤为研究对象,分析了冠幅内、外距柽柳主茎不同距离、不同深度的土壤样本的理化性质、酶活性以及土壤氮矿化(Nm)、硝化速率(Nn),旨在阐明:(1)盐渍化环境中肥岛效应及土壤养分、离子的变化特征;(2)肥岛效应下土壤中相关酶,如脲酶(Ure)、蛋白酶(Pro)、硝酸还原酶(Nit)活性变化特征及其与土壤养分之间关系;(3)肥岛效应下盐渍化土壤Nm、Nn的变化特征。主要研究结果如下:

(1)荒漠盐渍化环境中,肥岛效应对土壤的改良作用主要体现在增加土壤有机质(SOM)、全氮(TN)和K离子,并显著降低土壤中Na+、Mg2+及Ca2+等盐离子含量。重度盐渍化区域的肥岛效应强于轻度盐渍化区域。(2)土壤Ure、Pro与SOM、TN含量之间呈显著正相关。土壤电导率(EC)与Ure,Pro无显著相关性,但与Nit含量之间呈显著正相关;盐渍化程度及SOM,TN显著影响了土壤酶活性。(3)土壤EC与Nn呈极显著负相关,当土壤EC>20 dS m-1时,土壤Nn几乎完全被抑制;SOM与Nm呈极显著正相关,土壤EC对Nm影响不显著。(4)盐渍化显著降低了群落物种多样性。

Other Abstract

Soil salinization is a serious environmental problem worldwide, which not only causes huge economic losses, but also threats the survival and development of local residents and the ecological safety in the whole area. Therefore, it is crucial for us to understand the mechanism of desalinization effects by plants especially for halophytes in desert saline environment. Biological improvement has been widely considered better to improve soil salinization than physical and chemical methods. In this study, we collected soil samples from outer and inner layer of tamarisk canopy at both severe and mild salinization area of Shule river basin, northwestern region of Hexi corridor. The physical and chemical properties, enzyme activity, rates of nitrogen mineralization and nitrification of soil samples were measured. The main objectives were to illuminate: (1) The fertile island of tamarisk in the desert saline environment and its influence on the spatial distribution of nutrition and ion in soil. (2) The effect of fertile island on the activity of soil urease, protease, nitrate reductase and the relationships between soil enzyme activity and soil nutrients content. (3) The influence of fertile island on the rates of soil nitrogen mineralization and nitrification. The main results were as follows:

(1) Fertile island of tamarisk significantly increased soil organic matter (SOM), total nitrogen (TN) and Soluble potassium (K+), and significantly decrease the contents of salt cations e.g. sodium (Na+), magnesium (Mg2+) and calcium (Ca2+). The fertile island effects of tamarisk in severe salinization habitat is more significant than that in mild salinization habitat.(2) The activity of soil urease (Ure) and protease (Pro) are positively correlated with the SOM, and TN; Soil EC was not correlated with the activity of Ure and Pro but significantly correlated with Nit; These results suggected that the soil enzymes activities are significantly affected by the degree of salinization and content of SOM and TN.(3) Soil EC was significantly negatively correlated with the rate of soil nitrification (Nn). Nn is almost completely inhibited when EC>20 dS m-1. SOM was significantly positively correlated with the rate of soil mineralization (Nm); Soil EC has no significant effect on Nm.(4) Plant species richness was significantly reduced by salinization.

URL查看原文
Language中文
Document Type学位论文
Identifierhttps://ir.lzu.edu.cn/handle/262010/221635
Collection生命科学学院
Recommended Citation
GB/T 7714
张书亭. 柽柳肥岛效应对土壤氮矿化及硝化速率的影响[D]. 兰州. 兰州大学,2017.
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