干旱区生态环境知识资源中心(Arid): 胡杨不同叶形光合特性、水分利用效率及其对加富CO2的响应

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	胡杨不同叶形光合特性、水分利用效率及其对加富CO2的响应
其他题名	Photosynthetic character and water use efficiency of different leaf shapes of populus euphratica and their response to co-2 enrichment
	苏培玺; 张立新; 杜明武; 毕玉蓉; 赵爱芬; 刘新民
来源期刊	植物生态学报
ISSN	1005-264X
出版年	2003
卷号	27 期号:1 页码:34-40
中文摘要	胡杨（Populus euphratica Oliv.）叶形多变化，大致归纳为杨树叶（卵圆形叶）和柳树叶（披针形叶）两大类。在内蒙古额济纳旗胡杨林自然保护区，选择成年树同时具有卵圆形叶和披针形叶的标准株，将枝条拉至同一高度，通过活性测定，比较了其光合特征、水分利用效率及对CO2加富的响应。结果表明：在目前大气CO2浓度下，当光强为1000mumol·m^-2·s^-1时，卵圆形叶（成年树主要叶片）（A）和披针形叶（成年树下部萌条叶片）（B）的净光合速率（Pn）分别为16.40mumolCO2·m^-2·s^-1和9.38mumolCO2·m^-2·s^-1；水分利用效率（WUE）分别为1.52mmolCO2·mol^-1H2O和1.18mmolCO2·mol^-1H2O；A的光饱和点和补偿点分别为1600mumol·m^-2·s^-1和79mumol·m^-2·s^-1，B的相对应值则为1500mumol·m^-2·s^-1和168mumol·m^-2·s^-1。当CO2浓度加富到450mumol·mol^-1时，A的光饱和点升高了150mumol·m^-2·s^-1，光补点降低了36mumol·m^-2·s^-1；而B的光饱和点降低了272mumol·m^-2·s^-1，光补偿点则升高了32mumol·m^-2·s^-1。这表明，柳树叶的光合效率较低，以维持生长为主；随着树体生长，柳树叶难以维系其生长，出现杨树叶，杨树叶更能耐大气干旱，光合效率高，通过积累光合产物，使胡杨在极端逆境下得以生存并能达到较高的生长量，这就是胡杨从幼苗到成年树叶形变化的原因。随着CO2加富，两种叶片表现出截然相反的响应，柳树叶的光合时间缩短，光能利用率减小；而杨树的光合时间延长，光能利用率提高。如果地下水位下降，近地层空气变干燥，或随着大气CO2浓度升高，气候变暖，柳树叶可能逐渐减少以至消失。
英文摘要	Populus euphratica Oliv. is an important tree species of desert riparian forest. Leaf shape of P. e-uphratica is variable but can be roughly classified into two types, namely poplar leaf and willow leaf. Representative leaves of these types were ovate and lanceolate respectively. In this study some standard adult plants with both ovate leaves and lanceolate leaves were selected from the Nature Reserve of Populus euphratica in E-jin Qi, Inner Mongolia (41°58’ N, 101°05’ E, 930 m a.s.l. ) . In this measurement, the branches were put at the same height, then live leaves were measured and their photosynthesis, transpiration and water use efficiency were compared using the 11-6400 Portable Photosynthesis System of Ll-cor; the response to CO-2 enrichment was also compared. The purpose of the study was to explore the cause responsible for the changes of leaf shape of P. euphratica , so as to provide a scientific basis for the protection of P. euphratica forest. In addition , the response of the different leaf shapes to increased CO-2 concentration was analyzed and the possible effects of climatic changes on the growth of P. euphratica were predicted.The results showed that under present atmospheric CO-2 concentration (350 umol . mol~-1) and 1 000 umol o m~-2 o s~-1 of light intensity, the net photosynthetic rates ( Pn) of ovate leaves (leaf blades of adult tree) (A) and lanceolate leaves (lower coppica shoot leaves of adult tree) (B) are 16.40 umol CO-2. m~-2s~-1 and 9.38 umol CO-2 m ~-2 o s ~-1 respectively; transpiration rates ( E ) are 10.8 mmol H-2O o m ~-2 o s ~-1 and 7.98 mmol H-2O .m~-2.s~-1 respectively; water use efficiency ( WUE) is 1.52 mmol CO-2^’mol~-1H-2O and 1.18 mmol CO-2^’ mol^^O respectively. Under these conditions, the light saturation and compensation points of A are 1 600umol m ~-2 o s~-1 and 79 umol m ~-2.s-1 respectively, while the corresponding values of B are 1 500 /umol m~-2 o s~-1 and 168 umol o m ~-2 o s ~-1. When CO-2 concentration reaches 450 umol mol and 1 000 [umol o m ~ -2 o s ~-1 of light intensity, the photosynthetic characteristics of A and B exhibited quite different responses. The Pn of A increased by 25.6%, to 20.60 umol CO-2-m.2^~1, whereas the Pn of B decreased by 10.0%, to 8.44 umol CO-2.m~-2. ’s’ . The E of both A and B decreased; values were 9.11 mmol H-2O-2 and 6.26 mmol H-2O.m~-2s~-1 respectively. The WUE of A and B was 2.26 mmol CO-2 mol and 1.35 mmol CO-2 mmol"H-2O respectively, i.e. WUE of A increased by 48. 7% and WUE of B increased by 14.4% . The light saturation of A rises by 150 /umol.m~-2- s~-1 but light compensation point falls by 36 umol-m~2> s"1, while the light saturation point of B falls by 272 umol o m ~-2 o s ~-1 and light compensation point rises by 32 /umol .m-~2 -s~-1. The two types of leaf blade exhibit completely contrary responses to CO-2 concentration elevation; the poplar leaves are more adapted to atmospheric CO-2 concentration elevation.This study shows that the willow leaves have a lower photosynthetic efficiency and so are likely mainly used to maintain normal growth. With the growth of the tree the willow leaves can no longer support normal growth and hence poplar leaves occur. Poplar leaves have higher resistance to atmospheric drought and higher photosynthetic efficiency. They can accumulate photosynthetic products to maintain the growth of P. euphrati-ca in extremely adverse environments and reach a higher increment. This seems to be the real cause responsible for leaf shape changes of P. euphratica from seedlings to adult trees. With the increase in CO-2 concentration the photosynthetic time of willow leaves shortens and light use efficiency decreases, but poplar leaves show the opposite tendency in these two respects. When the ground water level decreases and near-surface air becomes dry, or with climate warming due to increasing atmospheric CO-2 concentration, the number of willow leaves are predicted to decrease, even disappear.
中文关键词	胡杨 ; 叶形 ; 光合特性 ; 水分利用效率 ; 蒸腾作用 ; CO2加富 ; 荒漠 ; 响应
英文关键词	Photosynthesis Transpiration Water use efficiency CO-2 enrichment Diversiform-leaved poplar(Populus euphratica) Desert
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:1289819
来源机构	中国科学院西北生态环境资源研究院
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/204560
作者单位	中科院寒区旱区环境与工程所, 沙坡头站, 兰州, 甘肃 730000, 中国
推荐引用方式 GB/T 7714	苏培玺,张立新,杜明武,等. 胡杨不同叶形光合特性、水分利用效率及其对加富CO2的响应[J]. 中国科学院西北生态环境资源研究院,2003,27(1):34-40.
APA	苏培玺,张立新,杜明武,毕玉蓉,赵爱芬,&刘新民.(2003).胡杨不同叶形光合特性、水分利用效率及其对加富CO2的响应.植物生态学报,27(1),34-40.
MLA	苏培玺,et al."胡杨不同叶形光合特性、水分利用效率及其对加富CO2的响应".植物生态学报 27.1(2003):34-40.