Seasonal exchange of CO 2 and D 18 O-CO 2 varies with postfire succession in boreal forest ecosystems
Seasonal exchange of CO 2 and D 18 O-CO 2 varies with postfire succession in boreal forest ecosystems
复制标题
CO 2 和 D 18 O-CO 2 的季节性交换随着北方森林生态系统火后演替的变化而变化
DOI：
--
复制
发表时间：
2006
期刊：
影响因子：
--
通讯作者：
H. P. Liu
中科院分区：
文献类型：
--
作者：
L. Welp;J. Randerson;H. P. Liu
[1]北纬高纬度地区大气CO 2和d18 O-CO 2的季节循环有可能作为响应气候变化的生态变化指标。对这些观测结果的有效解释需要了解不同物种和生态系统如何促进生物圈-大气交换。本文研究了寒带森林生态系统林龄对CO 2和d18 O-CO 2通量季节分布的影响。我们使用涡旋相关方差测量了阿拉斯加内陆3年烧伤疤痕、15年颤杨林和80年黑云杉林的净co2通量。通过将各林分生态系统水池氧同位素组成测量值与实测co2通量相结合，预测了半小时d18 o - co2通量，并利用单箱大气模型相对比较了林分年龄对co2和d18 o - co2季节循环形态和幅度的影响。与80年林分相比，15年林分盛夏生长期较短，生态系统净吸收率较高，导致季节co2幅值较大，大气co2吸收延迟。春季和初夏15年林分的初级生产总等强迫水平降低，导致大气d18o - co 2在4月至6月期间比80年林分的通量增加得更为缓慢。分析表明，北纬高纬度地区森林干扰的增加会延迟co2的减少阶段，但会提前co2的减少阶段。
[ 1 ] Seasonal cycles of atmospheric CO 2 and d 18 O-CO 2 at high northern latitudes have the potential to serve as indicators of ecological change in response to climate changes. Effective interpretation of these observations requires an understanding of how different species and ecosystems contribute to biosphere-atmosphere exchange. Here we examined the effect of postfire stand age in boreal forest ecosystems on the seasonal distribution of CO 2 and d 18 O-CO 2 fluxes. We measured net CO 2 fluxes in a 3-year burn scar, a 15-year trembling aspen stand, and an 80-year black spruce stand in interior Alaska using eddy covariance. By combining measurements of the oxygen isotopic composition of ecosystem water pools at each stand with measured CO 2 fluxes, we predicted half-hourly d 18 O-CO 2 fluxes and used a one-box atmosphere model to make relative comparisons of the effect of stand age on the shape and amplitude of the seasonal cycle of CO 2 and d 18 O-CO 2 . A shorter growing season and higher rates of net ecosystem uptake during midsummer at the 15-year stand resulted in a larger seasonal CO 2 amplitude and a delay in the drawdown of atmospheric CO 2 as compared with the 80-year stand. Reduced levels of gross primary production isoforcing from the 15-year stand during spring and early summer caused atmospheric d 18 O-CO 2 to increase more gradually between April and June as compared with fluxes from the 80-year stand. Our analysis suggests that increased boreal forest disturbance would delay the phase of CO 2 drawdown at high northern latitudes, but would advance the phase of d 18 O-CO 2 drawdown.
影响因子：
2
作者：
A. Sugimoto;Nao Yanagisawa;D. Naito;N. Fujita;T. Maximov
通讯作者：
A. Sugimoto;Nao Yanagisawa;D. Naito;N. Fujita;T. Maximov