Successional changes in live and dead wood carbon stores: implications for net ecosystem productivity
Successional changes in live and dead wood carbon stores: implications for net ecosystem productivity
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DOI：
10.1093/treephys/22.2-3.77
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发表时间：
2002-02-01
期刊：
影响因子：
4
通讯作者：
Harmon, ME
中科院分区：
文献类型：
--
作者：
Janisch, JE;Harmon, ME
如果要将森林用于CO2减缓项目，就必须了解和量化干扰对净生态系统生产力的影响（NEP;即，生态系统碳（C）储量随时间的变化。我们研究的影响，活树和粗木质残体（CWD）NEP在次生演替的基础上收集的数据沿着500年的时间序列的风河游侠区，华盛顿。我们开发了一个简单的活木和死木积累和分解的统计模型来预测NEP木质成分的变化，我们称之为NEPw。从负到正的净相对湿度的过渡，在一系列的情况下，没有到所有的木材被留在干扰后，发生在0和57年之间的干扰。这种过渡的时间减少活树生长率的增加，并增加CWD离开后，干扰增加。所有情景的最大和最小净有效压力分别为3.9和-14.1 Mg C ha（-1）year（-1）。最大活碳储量和总木材碳储量分别为319和393 Mg C ha（-1），达到约200年后的干扰。各林分CWD的分解速率（k）在0.013 ~ 0.043年（-1）之间。更新林分平均活木质量达到采伐后残留的CWD平均质量需要41年，500年生林分平均CWD质量需要40年，150年以上的老林分平均活木和死木总量需要150年。再生林储存了大约一半的木材C的剩余附近的古老的森林（主要年龄500年），表明古老的森林转换为年轻的管理森林的结果在一个显着的C净释放到大气中。
If forests are to be used in CO2 mitigation projects, it is essential to understand and quantify the impacts of disturbance on net ecosystem productivity (NEP; i.e., the change in ecosystem carbon (C) storage with time). We examined the influence of live tree and coarse woody debris (CWD) on NEP during secondary succession based on data collected along a 500-year chronosequence on the Wind River Ranger District, Washington. We developed a simple statistical model of live and dead wood accumulation and decomposition to predict changes in the woody component of NEP, which we call NEPw. The transition from negative to positive NEPw, for a series of scenarios in which none to all wood was left after disturbance, occurred between 0 and 57 years after disturbance. The timing of this transition decreased as live-tree growth rates increased, and increased as CWD left after disturbance increased. Maximum and minimum NEPw for all scenarios were 3.9 and -14.1 Mg C ha(-1) year(-1), respectively. Maximum live and total wood C stores of 319 and 393 Mg C ha(-1), respectively, were reached approximately 200 years after disturbance. Decomposition rates (k) of CWD ranged between 0.013 and 0.043 year(-1) for individual stands. Regenerating stands took 41 years to attain a mean live wood mass equivalent to the mean mass of CWD left behind after logging, 40 years to equal the mean CWD mass in 500-year-old forest, and more than 150 years to equal the mean total live and dead wood in an old-growth stand. At a rotation age of 80 years, regenerating stands stored approximately half the wood C of the remaining nearby old-growth forests (predominant age 500 years), indicating that conversion of old-growth forests to younger managed forests results in a significant net release of C to the atmosphere.