干旱区生态环境知识资源中心(Arid): CO2浓度倍增和土壤干旱对两种幼龄沙生灌木碳分配的影响

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	CO2浓度倍增和土壤干旱对两种幼龄沙生灌木碳分配的影响
其他题名	INTERACIVE EFFECTS OF DOUBLED ATMOSPHERIC CO2 CONCENTRATIONS AND SOIL DROUGHT ON WHOLE PLANT CARBON ALLOCATION IN TWO DOMINANT DESERT SHRUBS
	许振柱; 周广胜; 肖春旺; 王玉辉
来源期刊	植物生态学报
ISSN	1005-264X
出版年	2005
卷号	29 期号:2 页码:281-288
中文摘要	利用大型环境生长箱研究了两种幼龄沙地优势灌木柠条(Caragana intermedia)和羊柴(Hedysarum mongolicum)对CO2浓度倍增和土壤干旱交互作用的响应.CO2浓度倍增并没有改善两种沙生灌木叶片的水分状况,而土壤干旱使叶片的相对含水量(RWC)显著降低.在土壤水分充足条件下,CO2浓度倍增促进两种沙生灌木植株生长,在干旱条件下则主要促进根的生长,提高根冠比.土壤干旱显著减少了植株生物量,但相对促进了根的生长,特别是显著提高了羊柴的根冠比.CO2倍增使稳定性碳同位素组分(delta13C)降低,但土壤干旱使之增加.两种沙生灌木叶片与根部的delta13C值呈极显著线性关系,羊柴的斜率大于柠条的,表明前者叶片与根部在光合产物分配上具有较高的生态可塑性,这和干旱条件下羊柴的根冠比增加相关联.羊柴的"源库"调节特性反映了对土壤水分胁迫具有较高的耐性.
英文摘要	Atmospheric CO2 concentrations are expected to double around the middle part of the 21st century. Plant growth might be favored by CO2 enrichment, but water limitation is a common stress for plant growth and productivity. At present, only a few studies have looked at the combined effects of CO2 enrichment and drought on plant ecophysiology. This experiment was conducted to investigate the responses of two dominant desert shrubs, Caragana intermedia and Hedysarum mongolicum, in western China to the interaction of doubled CO2 levels and soil drought in large environmental growth chambers (19 m2). In this paper, we employed different methods, including allometry and carbon isotope discrimination, to examine the effects of water availability on carbon allocation and stable carbon isotope composition (SnC) of the two desert shrubs under two CO2 concentrations. The objectives included the following: 1) to investigate the effects of soil drought and CO2 enrichment on plant biomass and delta~(13)C; 2) to investigate the effects of soil drought and CO2 enrichment on the allocation of dry matter and carbohydrates; and 3) to elucidate the adaptive strategies of C. intermedia and H. mongolicum to soil drought under doubled atmospheric CO2 concentrations. Compared to ambient CO2 concentrations, doubled CO2 concentrations did not improve the leaf water status, but soil drought significantly reduced the leaf relative water content (RWC). Doubled CO2 concentrations enhanced plant growth under well-watered conditions but increased root growth under drought conditions resulting in an increase in root to shoot ratios. Soil drought significantly reduced plant biomass and increased root to shoot ratios, especially for H. mon-golicum. The delta~(13)C values were reduced at doubled CO2 concentrations but increased under drought conditions. By plotting the leaf delta~(13)C values against the root delta~(13)C values, it was possible to assess carbon allocation and in-corporation into roots in relation to present biomass. There was a significant and linear relationship between leaf delta~(13)C and root delta~(13)C values, and the slope of H. mongolicum was greater than that of C. intermedia indicated a higher plasticity in the ability to change carbon allocation patterns. This resulted in higher root to shoot ratios in H. mongolicum under drought conditions. The results indicated thai both C. intermedia and H. mon-golicum had a higher tolerance to severe water deficits under doubled C02 conditions. Decreases in precipitation might accompany with future increases in atmospheric CO2 concentrations in the region dominated by these two species, suggesting diat distribution ranges of C. intermedia and H. mongolicum might be constrained. Our results suggest that H. mongolicum has a higher tolerance to environmental stress than C. intermedia. Future work should emphasize how to enhance the drought tolerance of plants in semiarid region under conditions of CO2 enrichment.
中文关键词	CO2浓度倍增 ; 土壤干旱 ; 柠条 ; 羊柴 ; 生物量 ; 碳含量 ; 分配
英文关键词	Doubled atmospheric CO2 Soil drought Caragana intermedia Hedysarum mongolicum Biomass Carbon content Carbon allocation Global climate change
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:1913267
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/2XILL650/206879
作者单位	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,肖春旺,等. CO2浓度倍增和土壤干旱对两种幼龄沙生灌木碳分配的影响[J]. 中国科学院植物研究所,2005,29(2):281-288.
APA	许振柱,周广胜,肖春旺,&王玉辉.(2005).CO2浓度倍增和土壤干旱对两种幼龄沙生灌木碳分配的影响.植物生态学报,29(2),281-288.
MLA	许振柱,et al."CO2浓度倍增和土壤干旱对两种幼龄沙生灌木碳分配的影响".植物生态学报 29.2(2005):281-288.