ISWC OpenIR  > 水保所知识产出(1956---)
黄土丘陵区生物结皮对水分入渗的影响及模拟
张培培
Subtype硕士
Thesis Advisor赵允格
2014-05
Degree Grantor中国科学院研究生院
Place of Conferral北京
Keyword生物结皮 发育阶段 基质土壤 入渗 模拟
Abstract

“退耕还林(草)”生态恢复工程实施后,生物结皮在黄土丘陵区大面积发育。目前
不同发育阶段生物结皮对水分入渗的影响尚不清楚,本文通过对不同发育阶段生物结
皮土壤的水力学参数、入渗参数的分析测定,研究了不同发育阶段生物结皮对水分入
渗的影响及机理,并对生物结皮土壤的水分入渗过程进行了模拟,旨在为明确生物结
皮在水分入渗过程中的作用,为有效管理生物结皮,合理利用水土资源促进植被恢复,
促进生态健康发展提供科学依据。取得如下结论:
1 )生物结皮导致土壤 的 斥水性增加, 但土壤斥水性随生物结皮演替逐渐降低。
土壤含水量及生物结皮的物种组成是生物结皮土壤斥水性的主要影响因素。
黄土丘陵区黄绵土没有斥水性,生物结皮发育后土壤的斥水强度和持久性均显著
增加,具轻微斥水性。生物结皮土壤的斥水性随生物结皮的演替逐渐降低,当结皮中
藓类盖度达 20%以上时,土壤斥水时间显著低于藻结皮土壤。生物结皮土壤的斥水性
与含水量及优势种有关。藓类生物结皮土壤的斥水性随着含水量的降低逐渐增加;藻
类生物结皮土壤的斥水性随含水量的变化呈双峰曲线。浅色藻结皮土壤斥水性约在
40%田间持水量时最大,而深色藻结皮、藻+少藓结皮、藓+少藻结皮、藓结皮四种结
皮层土壤的斥水性则在 20%田间持水量时最大。
2 )生物结皮增加了土壤 的 持水性和水分有效性。生物结皮发育后土壤的持水性
增加,土壤水分有效性也随着增加,但在生物结皮发育过程中土壤的持水性、水分有
效性降低。
3 )生物结皮影响水分入渗过程,影响幅度受制于基质土壤,生物结皮与基质土
壤之间的交互作用同时影响着水分入渗。生物结皮能够降低水分入渗速率,降低幅度
随着生物结皮的演替逐渐缓和。生物结皮对水分入渗过程的影响随基质土壤的不同而
发生变化。
4 )通过修订 Green-Ampt  模型,可用于 模拟生物结皮覆盖在黄绵土上的水分入
渗过程, 除浅藻结皮外,深藻、藻+ 少藓、藓+ 少藻、藓结皮覆盖下的水分入渗过程
的拟合结果与实测值吻合。校正的 Green-Ampt 模型将生物结皮对水分入渗过程的影
响归结为对导水率的影响,并假设水分入渗过程由生物结皮层控制。生物结皮覆盖在塿土、风沙土上的水分入渗过程的能量动力理论更为复杂,需要进行更深入研究。
关键词:生物结皮;发育阶段;基质土壤;入渗;模拟

Other Abstract

Biological soil crust (biocrusts) extensively developed after the “Grain for Green”
eco-project was implementated in the Loess Plateau region, there is a large area of
biocrusts in the region. So far, we had not clearly known what and how the biocrusts,
which were in different successional stages, had an effect on water infiltration. In the study,
soil hydraulic and infiltration parameters of biocrusts in different successional stages were
measured and analyzed so as to determiner effect of biocrusts in different successional
stages on water infiltration. Then the process of water infiltration was simulated. The study
was aimed at clarifying and definiting the role of biocrust played on water infiltration
process. The study may benifit effective management of biocrusts, rational utilization of
water and soil resources to promote vegetation restoration, promote the healthy
development of the ecosystem. The results were as follows.
(1) The formation of biocrusts lead to an increase of soil water repellence (SWR)
markedly. The SWR showed a decrease trend along with the succession of biocrusts.
Soil moisture content and the composition of biocrusts were the major influence
factors of SWR.
No SWR was observed on the loessal soil without bioctrust in Hilly and Gully Region
of the Loess Plateau. However, a slight SWR was developed on soil when biocrusts
presented, both in the intensity and persistence. SWR of biocrusts showed a decrease trend
along with the succession of biocrusts. SWR of biocrusts with the moss coverage above
20% was significantly lower than that of cyanobacterial crusts. SWR of biocrusts was
related to soil moisture and dominant species. SWR increased against the decrease of soil
water content for moss dominated biocrusts, while there was a bimodal curve as the
decrease of soil water content for the cyanobacterial biocrusts. For the light cyanobacterial
crust, SWR approached the maximum value at 40% of field water holding capacity. While  for the other four stages of biocrusts, which were dark cyanobacterial crust,
cyanobacterial and little moss crust, moss and little cyanobacterial crust as well as the
moss dominated crust, SWR reached the maximum value at 20% of field water holding
capacity.
(2) Soil water retention and moisture availability were increased with the
presentation of biocrusts. Soil water retention increased after the formation of biocrust,
along with the soil moisture availability. But the soil water retention and soil moisture
availability decreased during the development of biocrusts.
(3) Biocrusts showed an effect on the process of water infiltration, the range of
effection was subject to the matrix soil. Meanwhile, the interaction between biocrusts
and matrix soil effected the the process of water infiltration. Water infiltration rate was
reduced with biocrusts, the descent range relaxed as the succession of biocrust. The
influence of biocrust on water infiltration process varied with the change of matrix soil.
(4) Water infiltration process of Loessal soil covered with biocrusts can be
simulated by the revised Green - Ampt model. The model fitting infiltration rate of
soil covered with biocrusts were consistent with the measured values except for soil
covered with light cyanobacterial crust. For the revised Green-Ampt model, biocrusts
had an efffect on water infiltration process, boiled down to the influence of soil hydraulic
conductivity, and the water infiltration process is controlled by layer of biocrusts. The
energy dynamics theory of water infiltration process of biocrust covered on Aeolian sandy
soil and Lou soil were more complex than that on Loessal soil, so further research was
needed.
Key words: biological soil crusts, successional stage, matrix soil, infiltration, simulation

Language中文
Document Type学位论文
Identifierhttp://ir.iswc.ac.cn/handle/361005/9002
Collection水保所知识产出(1956---)
Recommended Citation
GB/T 7714
张培培. 黄土丘陵区生物结皮对水分入渗的影响及模拟[D]. 北京. 中国科学院研究生院,2014.
Files in This Item:
File Name/Size DocType Version Access License
黄土丘陵区生物结皮对水分入渗的影响及模拟(1926KB)学位论文 开放获取CC BY-NC-SAApplication Full Text
Related Services
Recommend this item
Bookmark
Usage statistics
Export to Endnote
Google Scholar
Similar articles in Google Scholar
[张培培]'s Articles
Baidu academic
Similar articles in Baidu academic
[张培培]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[张培培]'s Articles
Terms of Use
No data!
Social Bookmark/Share
All comments (0)
No comment.
 

Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.