干旱区生态环境知识资源中心(Arid): 羊草叶片气体交换参数对温度和土壤水分的响应

Arid

	羊草叶片气体交换参数对温度和土壤水分的响应
其他题名	Responses of gas exchnge characteristics in leaves of leymus chinensis to changes in temperature and soil moisture
	许振柱; 周广胜; 李晖
来源期刊	植物生态学报
ISSN	1005-264X
出版年	2004
卷号	28 期号:3 页码:300-304
中文摘要	采用生长箱控制的方法研究了羊草(Leymus chinensis)幼苗叶片光合参数对5个温度和5个水分梯度的响应和适应。结果表明：轻度、中度土壤干旱并没有限制羊草叶片的生长，对气体交换参数亦无显著影响，反映了羊草幼苗对土壤水分胁迫的较高耐性。叶片生物量以26℃时最大，其它依次为23℃、2()℃、29℃和32℃。温度升高使气孔导度和蒸腾速率增加，却使光合速率和水分利用效率降低。水分和温度对叶片生物量、光合速率、气孑L导度和蒸腾速率存在显著的交互作用，表明高温加强了干旱对叶片生长和气体交换的影响，降低了羊草对土壤干旱的适应能力。高温和干旱的交互作用将显著减少我国半干旱地区草原的羊草生产力。
英文摘要	Drought and high temperature often occur simultaneously in arid and semiarid regions, but few investigators have studied the interactions between these two stresses. Our objective was to compare the effects of soil moisture, temperature and their interactions on the photosynthesis and growth of Leymus chinensis. Plants were subjected to different soil moisture regimes (relative soil water content ranged from 25% to 80% ) at tem peratures of 20, 23, 26, 29 and 32 °C in a controlled environment. Under sufficient soil moisture conditions, both net photosynthetic rates and water use efficiency decreased with increasing temperature whereas both stom-atal conductance and transpiration rates increased. There were no significant effects of soil moisture alone on net photosynthetic rates but significant soil moisture-temperature interactive effects were observed; net photo-synthetic rates increased under conditions of moderate soil drought at 20 - 26 °C but were significantly reduced under drought conditions at extremely high temperature (32 °C) . Water use efficiency showed a similar re sponse to changes in temperature and soil moisture as net photosynthetic rates. Soil moisture did not signifi cantly affect leaf stomatal conductance or transpiration rates indicating that higher adaptive ability to soil drought may be exhibited under these experimental conditions. However, under all soil moisture conditions, both net photosynthetic rates and water use efficiency always decreased with increasing temperature whereas both stomatal conductance and transpiration rates always increased with increasing temperature. Leaf biomass also responded to changes in soil moisture and temperature. The leaf biomass was greatest under conditions of light to moderate soil drought at temperatures from 20-26 °C but decreased with decreasing soil moisture at higher temperatures of 29 t and 32 °C . Leaf biomass of plants grown at 26 t was greatest under sufficient soil moisture and light drought conditions, but the leaf biomass at 23 t was greatest under moderate to high drought conditions. These results suggest that the optimal growing temperature might be lowered under droughty conditions. Leaf biomass was reduced in plants grown at higher temperatures ( 29 T! and 32 t) under all soil moisture regimes. Interactions between water stress and temperature were highly significant for several physio logical processes examined. Leaf gas exchange characteristics and growth were more impacted by drought con ditions at high temperatures than at low temperatures. Similarly, the productivity of L. chinensis was reduced more by the combined stresses of drought and high temperature than by either stress alone and much of the ef fect was on photosynthetic processes. Our research suggests that the decreased precipitation and increased tem peratures forecasted for this semi-arid region due to global climate change could adversely affect the distribution and abundance of L. chinensis . To conserve this species, future research should focus on ways to enhance the drought tolerance of L. chinensis at high temperatures.
中文关键词	温度
英文关键词	Temperature
类型	Article
语种	中文
国家	中国
收录类别	CSCD
WOS类目	Plant Sciences
WOS研究方向	Plant Sciences
CSCD记录号	CSCD:1635730
来源机构	中国科学院植物研究所
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/205657
作者单位	许振柱, 中国科学院植物研究所, 植被数量生态学重点实验室, 北京 100093, 中国.; 周广胜, 中国科学院植物研究所, 植被数量生态学重点实验室, 北京 100093, 中国.; 李晖, 中国科学院植物研究所, 植被数量生态学重点实验室, 北京 100093, 中国.
推荐引用方式 GB/T 7714	许振柱,周广胜,李晖. 羊草叶片气体交换参数对温度和土壤水分的响应[J]. 中国科学院植物研究所,2004,28(3):300-304.
APA	许振柱,周广胜,&李晖.(2004).羊草叶片气体交换参数对温度和土壤水分的响应.植物生态学报,28(3),300-304.
MLA	许振柱,et al."羊草叶片气体交换参数对温度和土壤水分的响应".植物生态学报 28.3(2004):300-304.