芦苇根孔在湿地生态系统中的动态和功能

基本信息
批准号:39970152
项目类别:面上项目
资助金额:14.00
负责人:王大力
学科分类:
依托单位:中国科学院生态环境研究中心
批准年份:1999
结题年份:2002
起止时间:2000-01-01 - 2002-12-31
项目状态: 已结题
项目参与者:刘国华,王星,单保庆,戴小君,兰智文
关键词:
芦苇根孔功能
结项摘要

The structure and spatial distribution of root channels, the hydrochemistry in the lake (ditch) water and subsurface water within the reed-bed/ditch system, and the matter transport affected by root channels were studied in the land/inland water ecotones with reed domination in Baiyangdian Lake, China..(1) It is found, as the first report, that the root channels formed by hydrophytes thrive in the ecotone soil. According to the statistical results from 17 field profiles, the root channels of reeds are mainly distributed above 120cm along the profile and particularly concentrated at 20-70cm. The area of root channels over 40-60cm section occupies more than 2.2% of the profile section area. The ratios of dead root channels to living ones account for 48.4% and 51.6%, respectively. Over 50% root channels have a diameter of less than 5mm. However, 90% of the root channel area is composed of root channels with diameter of more than 10mm. The wetland root channels spread predominantly along horizontal direction underground. The dye tracer experiment and hydraulic conductivity determination consistently show that the wetland root channels can quickly transport water to far distance within ecotones and consequently provide the transport, adsorption and transformation interface for pollutants such as nitrogen and phosphorus..(2) Field work well verified the new purification mechanism by root channels in the land/inland water ecotone. The purification mechanism of ecotone indicates that the root channels can freely exchange the water between land and water body as far as 4-8 m when the lake water level fluctuates, which considerably increases the purification efficiency by reed bed system. Here the soluble pollutants may be adsorbed or degraded by ecotone soil minerals. The reed-bed/ditch system can achieve best self-purification efficiency at sea level of 8 m. When the lake level rises from 7.3 m to 8.1 m, the concentrations of ammoniacal nitrogen (NH4+-N), total nitrogen (TN), soluble reactive phosphorus (SRP) and total phosphorus (TP) reduce by 90%, 64%, 99%, and 92%, respectively, at 4 m range within reed bed. However, during dry year, the lake level is lower than the root channel zone and only 6.5 m or less, and the purification zone is limited at 0.5 m range at the boundary of reed bed. At sea level of 8 m, the boundary length of effective purification zone in the lake reaches 7670 km and the corresponding effective root channel volume arrives at 9.0×106m3. While at 6.5 m, the length and volume decrease to only 1530 km and 2.8×104m3..(3) The main hydrochemical characteristics of ecotone subsurface water are characterized by high concentrations of CO2, hardness and alkalinity and low dissolved oxygen contents. In the subsurface water of reed beds, the partial CO2 pressure was 23-704 times of that in the atmosphere and the partial O2 pressure was 5-34 % of atmospheric O2 pressure. Root channels of reeds might serve as a unidirectional "CO2 pump" for transporting CO2 into subsurface water. The main ions exhibit spatial gradients from the edge to the center of reed beds. The change of hydrochemical type of the subsurface water occurs at the landward 0.5 m away from the edge of reed bed. The dominant cations in the ditch water and subsurface water are Na+ and Ca2+ respectively. The nutrients in the subsurface water of reed beds maintain low concentrations and vary little with the nutrient level in the lake (ditch) water.(4) The reed bed system, scattered ditches and open lake waters constitute the reed-bed/ditch system in Baiyangdian Lake, in which the reed bed system is composed of reed community, reed-bed soil, and underground root channel system of reeds as trinity. The width of reed beds and shallow ditches is generally 30-40 m and 5-10 m. Within such range of width, wetland root channels are equivalent to "connecting vessels" between reed beds and ditches, thus quickly moving water into the deep side of ecotone. Since multitudinous shallow ditches are connected to watercourses and lakes, this landscape structure significa

本研究拟以白洋淀典型湿地生态系统为研究对象,研究芦苇根在土壤不同深度上的空间分布、径级组成、季节动态以及新老交替规律。同时探讨芦苇根孔在土壤优先水流、溶质传输中的作用。植物根孔的系统研究不仅可以丰富我国在土壤大孔隙和植物根孔方面的研究内容,而且还将为我国利用湿地和生态滤池处理污染水、污泥等新技术提供理论基础。

项目摘要

项目成果
{{index+1}}

{{i.achievement_title}}

{{i.achievement_title}}

DOI:{{i.doi}}
发表时间:{{i.publish_year}}

暂无此项成果

数据更新时间:2023-05-31

其他相关文献

1

病毒性脑炎患儿脑电图、神经功能、免疫功能及相关因子水平检测与意义

病毒性脑炎患儿脑电图、神经功能、免疫功能及相关因子水平检测与意义

DOI:10.13210/j.cnki.jhmu.20190508.001
发表时间:2019
2

覆膜开孔条件下新疆地区潜水蒸发及水热关系研究

覆膜开孔条件下新疆地区潜水蒸发及水热关系研究

DOI:
发表时间:2013
3

大倾角煤层无人工作面深孔爆破落煤参数设计

大倾角煤层无人工作面深孔爆破落煤参数设计

DOI:10.3963/j.issn.1001-487X.2020.02.006
发表时间:2020
4

水泥基复合材料Seebeck热电性能研究现状与展望

水泥基复合材料Seebeck热电性能研究现状与展望

DOI:10.19817/j.cnki.issn1006-3536.2021.09.047
发表时间:2021
5

固态上转换材料制备及其性能

固态上转换材料制备及其性能

DOI:10.13550/j.jxhg.20170158
发表时间:2018

王大力的其他基金

相似国自然基金

1

芦苇型水陆交错带湿地根孔及根际环境对氮素去除的影响及其机理研究

批准号:21307025
批准年份:2013
负责人:郭艳杰
学科分类:B0605
资助金额:25.00
项目类别:青年科学基金项目
2

湿地芦苇根圈固氮甲烷氧化菌的分布特征及其功能耦合机制研究

批准号:41563009
批准年份:2015
负责人:包智华
学科分类:D0312
资助金额:43.00
项目类别:地区科学基金项目
3

滨海湿地芦苇根际PAHs降解功能古菌群落组成与多样性研究

批准号:41301333
批准年份:2013
负责人:马斌
学科分类:D0701
资助金额:26.00
项目类别:青年科学基金项目
4

崇西重建的芦苇湿地生态过程及其根际微生物研究

批准号:40871243
批准年份:2008
负责人:何池全
学科分类:D0716
资助金额:39.00
项目类别:面上项目