Increasing water-use efficiency and age-specific growth responses of old-growth ponderosa pine trees in the Northern Rockies
Increasing water-use efficiency and age-specific growth responses of old-growth ponderosa pine trees in the Northern Rockies
复制标题
DOI：
10.1111/j.1365-2486.2010.02209.x
复制
发表时间：
2011-01-01
影响因子：
11.6
通讯作者：
Soule, Peter T.
中科院分区：
文献类型：
--
作者：
Knapp, Paul A.;Soule, Peter T.
对黄松径向生长反应进行了研究。在1905-1954年和1955-2004年期间进行了一项研究，以确定大气中二氧化碳浓度升高导致的固有水分利用效率(IWUE)增加的影响是否具有年龄性。我们从落基山脉北部的五个地点收集了209个岩芯，并利用1850年至2004年的碳同位素数据计算了IWUE。标准化的径向生长反应是年龄相关的，在四个地点和所有地点的总和的后期，老树表现出显著高于年轻树的值。在前期，无论是单个立地还是组合立地，径向生长都没有显著差异。1955-2004年间iWUE的增长比1905-1954年间高出11%，iWUE的五年期波动与1850-2004年间老树的径向生长显著相关。幼树径向生长与IWUE相关不显著。我们的结果表明：(1)老生长的黄松林对大气CO2浓度升高的反应是年龄特有的；(2)老树的径向生长增加与IWUE的增加相一致；(3)黄山松在其生命的第三、第四和第五个世纪的生长速度有所增加；(4)1955-2004年的特定年龄的生长反应至少是自16世纪中叶以来的独特的。
We examined radial growth responses of ponderosa pine (Pinus ponderosa var. ponderosa) between 1905-1954 and 1955-2004 to determine if the effects of increased intrinsic water-use efficiencies (iWUE) caused by elevated atmospheric CO2 concentrations were age-specific. We collected 209 cores from five sites in the Northern Rockies and calculated iWUE using carbon isotope data from 1850 to 2004. Standardized radial growth responses were age dependent, with older trees exhibiting significantly higher values than younger trees during the later period at four sites and all sites combined. No significant differences in radial growth existed either for the individual sites or combined site during the earlier period. Increases in iWUE during 1955-2004 were 11% greater than during 1905-1954, and pentadal fluctuations in iWUE were significantly correlated with the radial growth of older trees from 1850 to 2004. Radial growth of younger trees and iWUE were not significantly correlated. Our results suggest that: (1) responses to elevated atmospheric CO2 in old-growth ponderosa forests are age-specific; (2) radial growth increases in older trees coincided with increased iWUE; (3) ponderosa had increased growth rates in their third, fourth, and fifth centuries of life; and (4) age-specific growth responses during 1955-2004 are unique since at least the mid-16th century.