Temporal variation of &delta;<sup>13</sup>C of larch leaves from a montane boreal forest in Mongolia

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	Temporal variation of delta¹³C of larch leaves from a montane boreal forest in Mongolia
	Li Sheng-Gong
	2007
关键词	Ecosystems Nitrogen Photosynthesis
英文摘要	This paper reports the temporal variation (2002-2004) in foliar δ¹³C values, which are indicative of long-term integrated photosynthetic and water use characteristics, of Siberian larch (Larix sibirica Ledeb.) trees in a montane forest at Mongonmorit, NE Mongolia. At the stand, the δ¹³C value for understory shaded leaves was more negative by 2‰ on average than that for sunlit leaves sampled concurrently from open and sun-exposed environments in a forest gap. The δ¹³C value of both sunlit and shaded leaves showed pronounced intra- but relatively small inter-seasonal variations. The δ¹³C value was more positive for juvenile than mature leaves. We conjecture that juvenile leaves may derive carbon reserves in woody tissues (e.g., stems). Regardless of leaf habitats, the δ¹³C value was also affected by insect herbivores occurred in mid summer of 2003, being more negative in newly emerging leaves from the twigs after defoliation than in non-defoliated mature leaves. This pattern seems to contrast with that for the juvenile leaves in the early growing season. We surmise that the newly emerging leaves used stored organic carbon that was depleted due to fractionation during remobilization and translocation for leaf regrowth. There was also intra- and inter-seasonal variation in the foliar N concentrations and C:N ratios. A good positive (negative) correlation between the foliar δ¹³C values and N concentrations (C:N ratios) was also observed for both sunlit and shaded leaves, suggesting that the relationship between water and nitrogen use is a crucial factor affecting the plant carbon-water relationship in this mid latitude forest with a cold semiarid climate. Our isotopic data demonstrate that the larches in NE Mongolia exhibits relatively higher water use efficiency with a distinct within-season variability. © 2007 Springer-Verlag.
出处	Trees - Structure and Function
卷	21 期:4 页:479-490
收录类别	EI
语种	英语
内容类型	EI期刊论文
源URL	[http://ir.igsnrr.ac.cn/handle/311030/24806]
专题	地理科学与资源研究所_历年回溯文献
推荐引用方式 GB/T 7714	Li Sheng-Gong. Temporal variation of delta¹³C of larch leaves from a montane boreal forest in Mongolia. 2007.