干旱区生态环境知识资源中心(Arid): 灌丛化的蒸散耗水效应数值模拟研究以内蒙古灌丛化草原为例

Arid

	灌丛化的蒸散耗水效应数值模拟研究以内蒙古灌丛化草原为例
其他题名	Shrub encroachment effect on the evapotranspiration and its componentA numerical simulation study of a shrub encroachment grassland in Nei Mongol, China
	王芑丹 1; 杨温馨 1; 黄洁钰 1; 徐昆 1; 王佩 2
来源期刊	植物生态学报
ISSN	1005-264X
出版年	2017
卷号	41 期号:3 页码:348-358
中文摘要	灌丛化是干旱半干旱草原一种常见的全球性变化现象,由于野外土壤、灌丛和草本的蒸散耗水难于拆分的限制,关于灌丛化蒸散耗水效应的研究较少。该文将已有的二源模型应用于我国内蒙古灌丛化草原估算其蒸散发,并用波文比系统观测结果对模型进行了率定。研究结果表明改进的模型可以较好地重建灌丛化草地的蒸散发特征;敏感性分析结果表明模型输入变量及参数对蒸散发组分拆分结果产生的误差较小。在此基础上进行了灌丛化的情景模拟,研究其耗水效应。结果表明:灌丛化对蒸散发总量影响较小,而对蒸散发组分影响较大。灌丛化初期盖度5%、中期盖度15%及后期盖度为30%的情境下,对应的生长季内蒸散发(ET)平均值分别为182.97、180.38和176.72 W·m~(-2);土壤蒸发(E)占蒸散发比率(E/ET)平均值分别为52.9%、 53.9%和55.5%。灌丛化从初期到中期、中期至后期,蒸散发降幅平均值分别为0.34%和0.44%, E/ET升幅分别达2.04%及3.25%。该研究结果表明在内蒙古太仆寺旗站点灌丛化导致的土壤水分差异并不明显,但随着灌丛化加剧,灌丛逐渐替代草本,改变了原有的生态系统结构,植被叶面积指数变小,导致冠层导度降低。研究结果强调我国半干旱草原区灌丛化加剧对生态系统总蒸散耗水量影响不大,但其土壤蒸发无效损耗快速增加会导致系统水分利用效率降低。
英文摘要	Aims Shrub encroachment is a common global change phenomenon occurring in arid and semi-arid regions. Due to the difficulty of partitioning evapotranspiration into shrub plants, grass plants and soil in the field, there are few studies focusing on shrub encroachment effect on the evapotranspiration and its component in China. This study aims to illustrate shrub encroachment effect on evapotranspiration by the numerical modeling method. Methods A two-source model was applied and calibrated with the measured evapotranspiration (ET) by the Bowen ratio system to simulate evapotranspiration and its component in a shrub encroachment grassland in Nei Mongol, China. Based on the calibrated model and previous shrub encroachment investigation, we set three scenarios of shrub encroachment characterized by relative shrub coverage of 5%, 15% and 30%, respectively, and quantified their effects caused by shrub encroachment through localized and calibrated two-source model. Important findings The two-source model can well reconstruct the evapotranspiration characteristics of a shrub encroachment grassland. Sensitivity analysis of the model shows that errors for the input variables and parameters have small influence on the result of partitioning evapotranspiration. The result shows that shrub encroachment has relatively small influence on the total amount of ET, but it has clear influence on the proportion of the components of evapotranspiration (E/ET). With shrub coverage increasing from 5% to 15% and then 30%, the evapotranspiration decreased from 182.97 to 180.38 and 176.72 W·m~(-2), decreasing amplitude values of 0.34% and 0.44%, respectively. On average, E/ET rises from 52.9% to 53.9% and 55.5%, increasing amplitude values to 2.04% and 3.25%. Data analysis indicates that shrub encroachment results in smaller soil moisture changes, but clear changes of ecosystem structure (decreasing ecosystem leaf area index while increasing vegetation height) which lead to the decrease of transpiration fraction through decreasing canopy conductance. The research highlights that, with the shrub encroachment, more water will be consumed as soil evaporation which is often regarded as invalid part of evapotranspiration and thus resulting in the decrease of water use efficiency.
中文关键词	灌丛化 ; 生态水文效应 ; 蒸散发 ; 二源模型 ; 数值模拟
英文关键词	shrub encroachment eco-hydrological effect evapotranspiration two-source model numerical simulation
语种	中文
国家	中国
收录类别	CSCD
WOS类目	AGRICULTURE MULTIDISCIPLINARY
WOS研究方向	Agriculture
CSCD记录号	CSCD:5963265
来源机构	北京师范大学
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/236957
作者单位	1.北京师范大学地理科学学部资源学院, 北京 100875, 中国; 2.北京师范大学地理科学学部资源学院, 地表过程与资源生态国家重点实验室, 北京 100875, 中国
推荐引用方式 GB/T 7714	王芑丹,杨温馨,黄洁钰,等. 灌丛化的蒸散耗水效应数值模拟研究以内蒙古灌丛化草原为例[J]. 北京师范大学,2017,41(3):348-358.
APA	王芑丹,杨温馨,黄洁钰,徐昆,&王佩.(2017).灌丛化的蒸散耗水效应数值模拟研究以内蒙古灌丛化草原为例.植物生态学报,41(3),348-358.
MLA	王芑丹,et al."灌丛化的蒸散耗水效应数值模拟研究以内蒙古灌丛化草原为例".植物生态学报 41.3(2017):348-358.