ISWC OpenIR  > 水保所知识产出(1956---)
生物结皮对土壤可蚀性的影响及机理
高 丽 倩
Subtype硕士
Thesis Advisor赵允格
2012-05
Degree Grantor中国科学院研究生院
Place of Conferral北京
Keyword生生物结皮 物种组成 生物量 土壤理化性质 土壤可蚀性
Abstract

黄土高原丘陵沟壑区退耕还林还草工程实施后,以藻类、苔藓及地衣等先锋物种
为主的生物结皮广泛发育,在促进土壤发育,改善土壤理化属性,降低土壤侵蚀等方
面具有显著作用。本文以典型黄土丘陵沟壑区不同组成与生物量的生物结皮土壤为研
究对象,通过野外调查和室内分析确定生物结皮对土壤理化性质的影响,并通过模型
估算及模拟降雨试验实测等方法,研究了生物结皮对土壤可蚀性(土壤可蚀性因子K
值)的影响,在此基础上,进一步通过数理统计分析揭示了生物结皮对土壤可蚀性的
影响机理,为考虑生物结皮的水土流失预报模型参数的选取提供科学依据。所得主要
结论如下:
(1)生物结皮显著影响土壤物理和化学属性,影响程度与其生物组成和生物量
有关。生物结皮的发育能够细化土壤,显著降低土壤容重、硬度和土壤pH,增加土
壤田间持水量、土壤孔隙度、粘结力、有机质含量和全氮含量。
颗粒组成表现为苔藓结皮和混生结皮(苔藓植物盖度约65%)粗粉粒和细砂粒含
量高于藻结皮。当生物结皮由初级阶段的藻结皮演替至60%-80%苔藓植物时,土壤
粗砂粒含量降低了86%,细砂粒含量增加了45%;不同类型生物结皮土壤容重表现
为藻结皮>苔藓结皮>混生结皮,演替后期土壤容重较初期藻结皮降低了15%;田间
持水量和土壤孔隙度表现为混生结皮>苔藓结皮>藻结皮,演替后期较初期藻结皮分
别增加了36%和14%;土壤硬度:苔藓结皮<混生结皮<藻结皮,演替后期较初期藻
结皮降低了68%;粘结力表现为苔藓结皮>混生结皮>藻结皮,生物结皮土壤粘结力
约是无结皮土壤的6~7 倍;有机质和全氮含量表现为苔藓结皮>混生结皮>藻结皮,
演替后期较初期藻结皮分别增加了161%和127%;pH:藻结皮>混生结皮>苔藓结皮,
随生物量的增加土壤pH 呈降低趋势。
(2)生物结皮的形成发育显著降低了土壤可蚀性,降低程度主要与生物结皮生
物量、生物组成、生物活性及下伏土壤质地有关。稳定期生物结皮土壤可蚀性较下层土壤降低了约17%;不同物种组成生物结皮土
壤可蚀性表现为:藻结皮>苔藓+藻混生结皮>苔藓结皮,混生结皮和苔藓结皮分别较
藻结皮降低了19%和21%,生物结皮土壤可蚀性随生物量的增加呈降低趋势,演替
后期的苔藓结皮土壤可蚀性K 值较初期藻结皮降低了21%;不同生物活性生物结皮
对土壤可蚀性的影响表现在季节差异上,雨季中生物结皮土壤可蚀性显著高于雨季前
和雨季后,雨季前和雨季后K 值较雨季中降低8%,雨季前和雨季后无显著差异;三
种质地土壤上生物结皮可蚀性表现为,砂壤>粉壤>砂土,生物结皮对粉壤可蚀性影
响较大。
(3)模拟降雨条件下生物结皮土壤可蚀性K 值较对照降低了约10 倍,进一步
证实生物结皮的形成显著降低了土壤可蚀性。
(4)生物结皮主要是通过增加有机质含量、全氮含量、粗粉粒含量(0.01~0.05
mm)、土壤总孔度及田间持水量,降低土壤容重和pH 而降低土壤可蚀性。其中对
生物结皮土壤可蚀性影响的主导因子为有机质含量,其次为粗粉粒含量、粉粒含量
及全氮含量。
相关分析表明,土壤容重和pH 与土壤可蚀性呈极显著正相关(P<0.01),粉粒、
粗粉粒、田间持水量、总孔度、有机质、全氮、C/N、pH 与土壤可蚀性呈极显著负
相关(P<0.01);砂粒含量与生物结皮土壤可蚀性呈显著正相关(P<0.05)。进一步主
成分分析得到,能够代表生物结皮土壤可蚀性的影响因素可概括为土壤结构特征、
土壤颗粒组成(土壤质地)以及生物结皮土壤中有机碳和全氮含量。并通过多元
逐步回归分析得到,生物结皮影响土壤可蚀性的主导因素依次为有机质、粗粉粒含
量、粉粒含量及全氮含量。
关键词:生物结皮;物种组成;生物量;土壤理化性质;土壤可蚀性

Other Abstract

Biological soil crust (biocrusts) that constituted by pioneer organismes such as algae,
mosses and lichens extensively developed in the Hilly Loess Plateau region after the
“Grain for Green” eco-project was implementated in the region. Biocrusts played a
significant role in that promoting soil development, improving soil physical and chemical
properties and the reducing of the soil erosion. In the paper, soil physical and chemical
properties were measured after a profound field survey so as to determine the effect of
biocrusts on soil efodibility (soil erodibility factor K value) with different composition and
biomass of biocrusts soil in the typical Hilly Loess Plateau region. We calculated the K
value of soil with different composition and biomass biocrusts by using the EPIC model
firstly. Then, the K value was measured by simulated rainfall under the control conditions.
Results of the study suggested that biocrusts exerted a significant influence on soil
erodibility, which would likely provide scientific basis to the mechanism of soil
antierodibility improvement by biocrusts and to the establishment of Soil Erosion Model
that take the biocrusts as an influence factor in Hilly Loess Plateau region.The main results
are as follows.
(1) Biocrusts influenced on soil physical and chemical properties, significantly. The
development of biocrusts could refine the soil, significantly reduce soil bulk density,
hardness and pH, and increase the soil field water holding capacity, soil porosity, cohesion,
organic matter content and total nitrogen content.
Particle composition showed that the content of coarse silt and fine sand of moss crust
and mix crust (mosses coverage was about 65%) were higher than that of caynobateria
biocrusts, significantly. When the biocrusts in the initial stage of the caynobateria biocrust  to 60%-80% mosses coverage, soil coarse sand content reduced 86%, and fine sand content
increased 45%; Different types of biocrusts soil bulk density presented as that:
caynobateria > mosses > mixed biocrust; in late successional stage soil bulk density of
caynobateria biocrust reduced 15% than that in the initial stage; Field water holding
capacity and the soil porosity were performance for the mixed > mosses > caynobateria
biocrust, but in later succession stage increased 36% and 14% respectively; Soil hardness:
mosses < mixed < caynobateria biocrust, in later succession stage caynobateria biocrust
decreased 68%; cohesion: mosses > mixed > caynobateria biocrust. The cohesion of
biocrusts about six to seven times than that in bare soil; Organic matter and total nitrogen
content : mosses > mixed > caynobateria biocrust, in succession later increased 161% and
127% respectively; pH: caynobateria > mixed > mosses biocrust, along with the increase
of biomass soil pH was decreasing.
(2) Development of biocrusts significantly reduced the soil erodibility, which was
related with biomass, composition, biological activity and the soil texture.
Soil erodibility of biocrusts at the stable stage was 17% lower than subsurface soil.
Soil erodibility of biocrusts with different species composition was shown as caynobateria
crust > mixed crust > moss crust,mixed biocrust and moss biocrust decreased respectively
19% and 21% than caynobateria crust. Soil erodibility of biocrusts decreased with the
increment of biocrusts biomass. The K value of mosses biocrusts soil in the later
succession stage was 21% lower than in early succession stage. Erodibiliy of biocrusts
soils were significant difference because of the biological activities of the organisms of
biocrusts in different seasons, erodibility of biocrusts soil at rainy reason was significantly
higher than those before rainy season and after rainy season. The K value before rainy
season and after rainy season were 8% lower than that at rainy season, and there was no
significant difference between it before rainy season and after rainy season. Erodibilty of
biocrusts soil on different textures were varied significantly, and the K values were
performed in the order like sandy loam soil > silt soil > sandy soil .,and biocrusts had
great influence on erodibility of silt soil.
(3) Soil erodibility of different composition biocrusts measured by simulated rainfall
confirmed the results of the calculation by the EPIC model, which was ten times less than
subsoil (soil of 5-10 cm), which was another evidence that the development of biocrusts
can significantly reduce soil erodibility.
(4) Biocrusts significantly reduced soil erodibility mainly because of increasing the
content of soil organic matter, total nitrogen, coarse silt, soil porosity and field water
holding capacity, and decreasing soil bulk density and pH. The dominant factor of  influencing soil erodibility of biocrusts was organic matter content, secondly for the
content of coarse silt, silt and total nitrogen.
The correlation analysis showed that there was a significant positive correlation
between soil erodibility and soil bulk density and pH (P<0.01), but a significant negative
correlation with silt, coarse silt, soil porosity, field water holding capacity, the content of
soil organic matter, total nitrogen content, C/N and pH (P<0.01). The content of sand had
positive correlation with soil erodibility of biocrusts (P<0.05). The results of principal
component analysis indicated that soil structure, soil particle composition and the content
of soil organic matter and total nitrogen could represent the main factor of influencing soil
erodibility of biocrusts. It showed that the main factor of influencing soil erodibility of
biocrusts was in sequence of soil organic matter, coarse silt, silt and total nitrogen by
multiple stepwise regression analysis.
Key Words:biological soil crust; species composition; biomass; soil physical and chemical
characteristics; soil erodibility

Language中文
Document Type学位论文
Identifierhttp://ir.iswc.ac.cn/handle/361005/8926
Collection水保所知识产出(1956---)
Recommended Citation
GB/T 7714
高 丽 倩. 生物结皮对土壤可蚀性的影响及机理[D]. 北京. 中国科学院研究生院,2012.
Files in This Item:
File Name/Size DocType Version Access License
生物结皮对土壤可蚀性的影响及机理.pdf(729KB)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
[高 丽 倩]'s Articles
Baidu academic
Similar articles in Baidu academic
[高 丽 倩]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[高 丽 倩]'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.