干旱区生态环境知识资源中心(Arid): 模拟降雨量变化与CO_2浓度升高对羊草光合特性和生物量的影响

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	模拟降雨量变化与CO_2浓度升高对羊草光合特性和生物量的影响
其他题名	Influences of precipitation regimes and elevated CO_2 on photosynthesis and biomass accumulation in Leymus chinensis
	刘玉英 1; 李卓琳 2; 韩佳育 2; 穆春生 2
来源期刊	草业学报
ISSN	1004-5759
出版年	2015
卷号	24 期号:11 页码:128-136
中文摘要	羊草作为欧亚大陆草原东缘干旱半干旱区域的优势种，现生产力已逐年降低。为明确未来降雨量变化和CO_2浓度升高对羊草草地变化的影响，我们模拟3个降雨量梯度(正常降雨量40%)和两个CO_2浓度(38020，76020 mumol/mol)进行了光合特性与生物量的研究。结果表明,降雨量变化和CO_2浓度的交互作用显著影响羊草的净光合速率等光合特性，地下生物量和根冠比，而不影响地上生物量。在目前CO_2浓度时随着降雨量的增加，以及在CO_2浓度升高时的降雨量由低降雨量增至正常降雨量，羊草的净光合速率、气孔导度、蒸腾速率和地上、地下及总生物量均显著增加，但在CO_2浓度升高，降雨量由正常降雨量增至高降雨量时上述指标无显著变化。根冠比在目前CO_2浓度时差异不显著，在CO_2浓度升高下低降雨量时显著增加。在降雨量相同条件下，CO_2浓度的升高使胞间CO_2浓度、水分利用效率显著增加，气孔导度和蒸腾速率显著降低。低降雨量时CO_2浓度升高对羊草净光合速率和生物量的促进作用显著高于正常降雨量和高降雨量，而高降雨量时CO_2浓度升高对羊草生物量没有促进作用。以上结果暗示着在目前CO_2浓度下，随着降雨量的增加，羊草生物量随之增加，在未来CO_2浓度升高的背景下，高降雨量年份对生物量的积累并无显著的促进作用，CO_2浓度升高可以补偿低水分条件对多年生根茎型禾草--羊草生长发育所造成的不利影响。
英文摘要	Leymus chinensis is a dominant, rhizomatous perennial C_3 species found in the grasslands of Songnen Plain, Northern China, where its productivity has decreased year by year due to environmental changes. As a dominant species growing in arid and semiarid regions, precipitation is a key factor limiting plant productivity. To determine how this species’ productivity responds to different precipitation regimes and increased CO_2 levels, we conducted an experiment that measured photosynthetic parameters, along with the accumulation and partitioning of biomass. Plants were subjected to combinations of three precipitation gradients (normal precipitation, normal40%) and two CO_2 levels (38020 and 76020 mumol/mol) in environment-controlled chambers. The interaction between increased CO_2 and precipitation had significant effects on photosynthetic parameters, belowground biomass and root∶shoot ratio, but no effect on aboveground biomass. Net photosynthetic rate, stomatal conductance, transpiration rate, aboveground and total biomass rose with increases in precipitation and CO_2 concentration, but no significant change was observed when precipitation increased from normal to high under CO_2 enrichment. There was no significant difference in the ratio of root to shoot among precipitation regimes at the low CO_2 condition, but it changed significantly with CO_2 enrichment and low precipitation. Water use efficiency and intercellular CO_2 concentration increased significantly when precipitation was low, but decreased when precipitation was high under CO_2 enrichment. The effect of elevated CO_2 on photosynthesis and biomass accumulation was more obvious at low precipitation than at normal or high precipitation. The results suggest that at ambient CO_2 levels, net photosynthetic rate and biomass of L. chinensis increase with precipitation, but that these measures are not further affected by additional precipitation when CO_2 is elevated. Furthermore, CO_2 may partly compensate for the negative effect of low precipitation on the growth and development of L. chinensis.
中文关键词	CO_2浓度 ; 降雨量 ; 羊草 ; 生物量 ; 光合特性
英文关键词	elevated CO_2 precipitation regime Leymus chinensis biomass accumulation photosynthesis
语种	中文
国家	中国
收录类别	CSCD
WOS类目	AGRONOMY
WOS研究方向	Agriculture
CSCD记录号	CSCD:5569482
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/232435
作者单位	1.吉林省气候中心, 长春, 吉林 130062, 中国; 2.东北师范大学草地科学研究所, 植被生态科学教育部重点实验室, 长春, 吉林 130024, 中国
推荐引用方式 GB/T 7714	刘玉英,李卓琳,韩佳育,等. 模拟降雨量变化与CO_2浓度升高对羊草光合特性和生物量的影响[J],2015,24(11):128-136.
APA	刘玉英,李卓琳,韩佳育,&穆春生.(2015).模拟降雨量变化与CO_2浓度升高对羊草光合特性和生物量的影响.草业学报,24(11),128-136.
MLA	刘玉英,et al."模拟降雨量变化与CO_2浓度升高对羊草光合特性和生物量的影响".草业学报 24.11(2015):128-136.