干旱区生态环境知识资源中心(Arid): 黑河中游荒漠绿洲过渡带多枝柽柳对地下水位变化的生理生态响应与适应

Arid

	黑河中游荒漠绿洲过渡带多枝柽柳对地下水位变化的生理生态响应与适应
其他题名	Ecophysiological responses and adaptation of Tamarix ramosissima to changes in groundwater depth in the Heihe river basin
	张佩; 袁国富; 庄伟; 薛沙沙
来源期刊	生态学报
ISSN	1000-0933
出版年	2011
卷号	31 期号:22 页码:6677-6687
中文摘要	以黑河中游荒漠绿洲过渡带主要建群种多枝柽柳成年体为研究对象,对野外不同地下水埋深处柽柳叶片生理生态特性进行观测和分析,评价分析多枝柽柳对地下水埋深差异和地下水位季节变化的响应过程和适应机制。结果显示:在相似大气环境条件下,不同地下水埋深之间,多枝柽柳叶片的生理生态指标没有明显差异,但对于地下水位的季节波动,则表现出较为明显的变化和响应;柽柳通过气孔的调节,在更深地下水埋深下,水分条件更差时,保持了稳定的气孔导度和较高的叶片胞间二氧化碳浓度,从而维持相对稳定的碳同化能力及较高水分利用效率,表现出较好的适应能力;在不同地下水埋深下,叶片生理生态指标随地下水位下降的响应特征呈现出明显差异,这种差异暗示了黑河中游荒漠绿洲过渡带多枝柽柳的适宜地下水位在3 m左右。
英文摘要	Areas in middle reaches of the Heihe river basin constitute a desert oasis ecotone. The normal growth of vegetation in this area is significantly affected by irrigation practices and seasonal groundwater level fluctuations. This is particularly true for groundwater dependent species. The continued decline of the groundwater level, due high levels of groundwater consumption for agricultural irrigation in the area, threatens the stability and sustainability of this transitional ecosystem. A field experiment was conducted on Tamarix ramosissima, one of the main species of this desert-oasis ecotone, to elucidate the response processes and adaptation mechanisms of this species to changes in groundwater depth. The groundwater depth differences examined included two conditions: spatial differences in absolute groundwater depth and seasonal fluctuations of the groundwater level. Field measurements were carried out at seven sites, where groundwater depth ranged from 0.75m to 7.05m. A number of leaf ecophysiological indicators were recorded, including, midday leaf net photosynthetic rate (P_s), transpiration rate (T_r), stomatal conductance (C), intercellular CO_2 concentration (C_i), and midday stem water potential (Psi_m). All measurements were made under similar meteorological conditions. The study was conducted from late June to early September. During this period groundwater levels at the different sites fell by differing amounts. The results show that P_s and T_r values among the seven sites were not notably different (the fitted trendline slopes were -0.24 for P_s, and -0.13 for T_r, respectively), indicating that there was little difference in the growth rates of T. ramosissima among sites with different absolute groundwater depth. However, P_s and T_r showed a clear decline with the main seasonal declines in groundwater level (the fitted trendline slopes were -10.10 for P_s, and -6.34 for T_r, respectively). These differing responses to changes in groundwater depth suggest that T. ramosissima may be adapted to the different absolute groundwater depths, but shows a clear response to rapid seasonal fluctuations of groundwater level. C values for T. ramosissima declined with decreasing Psi_m when Psi_m< 3.0MPa. However, C values increased slowly with decreasing Psi_m when Psi_m> 3.0MPa. Nonetheless, both C and C_i/C_a values among the seven sites were similar. These results suggest that T. ramosissima maintains a relatively stable carbon assimilation capacity at different absolute groundwater depths. This is achieved through stomatal regulation which results in stable stomatal conductance and thus stable leaf intercellular carbon dioxide concentration. On the other hand, seasonal declines in groundwater level could have a marked influence on the normal growth of T. ramosissima. The leaf physiological indicators for T. ramosissima showed different responses to seasonal groundwater level fluctuations. At sites where groundwater depths were less than 3m, the leaf gas exchange rates of T. ramosissima increased as the groundwater level declined. On the other hand, at sites where groundwater depths were more than 3m gas exchange rates decreased with a decline in groundwater level. These differences suggest that there is an optimal groundwater depth for T. ramosissima growth in this section of the Heihe river basin. The results indicate that this optimal groundwater depth is about 3m.
中文关键词	多枝柽柳 ; 荒漠绿洲过渡带 ; 地下水埋深 ; 光合速率 ; 蒸腾速率 ; 气孔导度
英文关键词	Tamarix ramosissima desert-oasis ecotone groundwater depth, photosynthesis transpiration stomatal conductance
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:4378824
来源机构	中国科学院地理科学与资源研究所
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/226976
作者单位	中国科学院地理科学与资源研究所, 中国科学院生态网络观测与模拟重点实验室, 北京 100101, 中国
推荐引用方式 GB/T 7714	张佩,袁国富,庄伟,等. 黑河中游荒漠绿洲过渡带多枝柽柳对地下水位变化的生理生态响应与适应[J]. 中国科学院地理科学与资源研究所,2011,31(22):6677-6687.
APA	张佩,袁国富,庄伟,&薛沙沙.(2011).黑河中游荒漠绿洲过渡带多枝柽柳对地下水位变化的生理生态响应与适应.生态学报,31(22),6677-6687.
MLA	张佩,et al."黑河中游荒漠绿洲过渡带多枝柽柳对地下水位变化的生理生态响应与适应".生态学报 31.22(2011):6677-6687.