干旱区生态环境知识资源中心(Arid): 毛乌素沙地油蒿群落冠层导度及影响因素

Arid

	毛乌素沙地油蒿群落冠层导度及影响因素
其他题名	Temporal variation and controlling factors of canopy conductance in Artemisia ordosica community
	王珊 1; 查天山 2; 贾昕 2; 吴雅娟 1; 白玉洁 1; 冯薇 2
来源期刊	北京林业大学学报
ISSN	1000-1522
出版年	2017
卷号	39 期号:3 页码:65-73
中文摘要	冠层导度(g_c)是影响植物蒸腾和光合作用的重要参数,对环境变化敏感。本研究利用涡度相关法于2015年5-10月对毛乌素沙地油蒿群落的潜热和显热通量进行连续观测,并同步观测空气温度(T_a)、相对湿度(RH)、光合有效辐射(PAR)、土壤含水量(VWC)、降雨(PP)等气象因子,结合Penman-Monteith的冠层导度逆转方程,了解g_c时间动态与变异机制。结果表明:研究区油蒿群落g_c日变化具有明显的季节差异,夏季(5-8月)g_c达到峰值的时间比秋季(9-10月)早约2h,约在10:00左右达到峰值,比水汽压亏缺(VPD)和PAR的峰值分别提前3~4h和1~2h,秋季g_c在中午12:00达到峰值后直接下降。PAR、VPD均对g_c有显著的调控作用,PAR和VPD对g_c的调控阈值分别是1200mumol/(m~2·s)和1.5kPa,小于阈值呈正相关,大于阈值呈负相关。30cm土壤含水量(VWC_30)是调控g_c的重要因子,当VWC_30大于0.16m~3/m~3时,g_c与VWC_30呈正线性关系。在高的土壤含水量条件(VWC_30≥0.16m~3/m~3)下,g_c对PAR和VPD的敏感性高于低土壤含水量(VWC_30<0.16m~3/m~3)条件。结果表明,土壤水分是调节荒漠生态系统冠层导度的关键因子,研究结果为荒漠生态系统水文过程模型的建立提供重要参考。
英文摘要	Canopy conductance (g_c) is an important factor influencing plant transpiration and photosynthesis, and it is sensitive to environmental factors. Evapotranspiration and environmental factors of a shrub ecosystem, which was dominated by Artemisia ordosica in northwestern China, were continuously measured using eddy covariance technique in growing season (May-October) in 2015. Meteorological variables including air temperature (T_a), relative humidity (RH), photosynthetic active radiation (PAR), soil volumetric water content (VWC), and precipitation (PP) were also measured. g_c was calculated using the inverted Penman-Monteith equation. Diurnal pattern in g_c revealed a clear seasonal trend, with g_c peaking 2 hours earlier in summer (from May to August) than autumn(from September to October )(10:00, 3-4hours and 1-2 hours before VPD and PAR). During growing season, g_c increased positively with vapor pressure deficit (VPD) and PAR, respectively, saturating at 1.5kPa and 1200mumol/(m~2·s), then decreasing with these variables when greater than their respective threshold.The g_c values had positive relationship with soil volumetric water content at 30cm depth (VWC_30) under high VWC_30 (≥0.16m~3/m~3) during the whole growing season. g_c was more responsive to PAR and VPD when VWC_30 was high. It was concluded that VWC played a critical role in regulating canopy conductance in desert ecosystems. Our results could potentially provide important baseline information towards hydrological model creation of arid and semi-arid ecosystems.
中文关键词	冠层导度 ; 土壤含水量 ; 半干旱区 ; 蒸腾 ; 光合作用
英文关键词	canopy conductance soil water content semiarid region transpiration photosynthesis
语种	中文
国家	中国
收录类别	CSCD
WOS类目	FORESTRY
WOS研究方向	Forestry
CSCD记录号	CSCD:5951968
来源机构	北京林业大学
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/235606
作者单位	1.北京林业大学水土保持学院, 100083; 2.北京林业大学水土保持学院, 林业生态工程教育部工程研究中心;;宁夏盐池毛乌素沙地生态系统国家定位观测研究站, 100083
推荐引用方式 GB/T 7714	王珊,查天山,贾昕,等. 毛乌素沙地油蒿群落冠层导度及影响因素[J]. 北京林业大学,2017,39(3):65-73.
APA	王珊,查天山,贾昕,吴雅娟,白玉洁,&冯薇.(2017).毛乌素沙地油蒿群落冠层导度及影响因素.北京林业大学学报,39(3),65-73.
MLA	王珊,et al."毛乌素沙地油蒿群落冠层导度及影响因素".北京林业大学学报 39.3(2017):65-73.