《Journal of Geophysical Research》杂志刊登“阿尔卑斯山高海拔气候下生态系统呼吸年际评估体系”

作者：Riveros-Iregui, Diego A.；Hu, Jia；Burns, Sean P.；Bowling, David R.；Monson, Russell K.

刊物：《Journal of Geophysical Research》，2011年，第116卷，G2期

关键词：针叶林；年际变化；keeling plot；时间滞后；水文单元

摘要： 本文就阿尔卑斯山亚高山森林地区，四季的生态系统呼吸作用中，释放的同位素碳13进行了测量。对不同生态系统下呼吸作用进行比对，与叶级气体交换理论预期相同，并且认证了之前对宽阔地理区域下生态呼吸作用与气候关系的研究。在平均湿润年的较干燥时期，昼夜呼吸作用呈现正相关，观察传统的趋势（即通过增加蒸汽压赤字（VPD）和空气温度（TAIR），以此降低负面的生态系统呼吸和土壤湿度）。在特定气候条件下（如晚融雪，生长季遭遇极端空气温度），昼夜呼吸作用呈现负相关,观察非传统的趋势（即，通过降低土壤湿度和负面的生态系统呼吸，来增加蒸汽压赤字与空气温度）。并对多种树木中提取的糖分使用碳同位素测量。结果表明，呼吸作用与气候间存在的关系可能取决于环境条件的综合作用。因此对生态系统呼吸变量进行了必要的描述及参数化，并采用同位素法分析了天气条件和变量水文体系下特定参数组合。

An interannual assessment of the relationship between the stable carbon isotopic composition of ecosystem respiration

and climate in a high-elevation subalpine forest

Authors: Riveros-Iregui, Diego A.；Hu, Jia；Burns, Sean P.；Bowling, David R.；Monson, Russell K.

Journal: Journal of Geophysical Research. Biogeosciences EISCI, 2011, 116(G2)

Key words: conifer；interannual；Keeling plot；time lag；hydrologic regimes

Abstract: We measured the carbon isotopic composition (d13C) of ecosystem respiration (d13CR) in a subalpine forest across four growing seasons to examine whether patterns in d13CR were consistent with those expected based on leaf‐level gas‐exchange theory, and in agreement with past studies of the relation between d13CR and climate conducted across broad geographic regions. Conventional trends (i.e., less negative d13CR with increased vapor pressure deficit (VPD) and air temperature (TAIR), and decreased soil moisture ( )) were observed when we focused on the driest portions of average‐wetness years and when d13CR was positively correlated with nighttime ecosystem respiration (RE). Nonconventional trends (i.e., more negative d13CR with decreased  , and increased VPD and TAIR) were observed under specific climatic conditions (e.g., late snowmelt; extreme TAIR late in the growing season), and when d13CR was negatively correlated with RE. These nonconventional trends were independently corroborated using d13C of extracted sugars from needles of dominant tree species at the site. Our results clearly demonstrate that the commonly reported relations between d13CR and climate may break down depending on the interactions among environmental conditions. Efforts to model and predict the variability of d13CR under changing climatic variables must characterize and parameterize the effects of unique combinations of weather conditions and variable hydrologic regimes, in combination with the susceptibility of photosynthetic isotope discrimination to extreme air temperatures.

原文链接：http://d.wanfangdata.com.cn/NSTLQK_NSTL_QKJJ0224598148.aspx

翻译：苏昕；审稿：陈康宁