Soil carbon fluxes and stocks in a Great Lakes forest chronosequence
Soil carbon fluxes and stocks in a Great Lakes forest chronosequence
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DOI：
10.1111/j.1365-2486.2008.01741.x
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发表时间：
2009-01
影响因子：
11.6
通讯作者：
Jianwu Tang;P. Bolstad;Jonathan G Martin
中科院分区：
文献类型：
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作者：
Jianwu Tang;P. Bolstad;Jonathan G Martin
我们测量了威斯康星州和密歇根州落叶林的时间序列中的土壤呼吸和土壤碳储量，以及微气象变量。时间序列包括：(1)4个新近干扰林分，包括采伐和反复焚烧林(焚烧)、放空和部分抢救林(吹倒)、采伐稀疏覆盖层(残留林)和完全采伐更新林(更新)；(2)4个平均年龄为10年的杨树幼林；(3)4个平均年龄为26岁的中间杨树林；(4)4个平均年龄为73年的北方成熟阔叶林；(5)一个平均年龄约为350年的老树林。我们拟合了基于现场的模型，并使用土壤温度的连续测量来估计2005年生长季(133-295天)的累积土壤呼吸。在整个生长季，烧毁林、排污林、残留林、更新林、幼林、中林、成熟林和老林地的土壤呼吸总量分别为513、680、747、747、794、802、690和571gCm−2。土壤呼吸的表观温度敏感度在更新林分中最高，从幼龄林到老龄林逐渐降低。在10℃时，累积土壤呼吸和基础土壤呼吸均在林分建立过程中增加，在中龄时达到峰值，然后随着年龄的增加而降低。采伐后0-60 cm土壤全碳开始下降，林分建立后土壤全碳增加。老树种在深层土壤中积累碳，而在表层土壤中不积累。我们的研究表明，土壤碳的长期动态在垂直深度和时间尺度上都是复杂的。
We measured soil respiration and soil carbon stocks, as well as micrometeorological variables in a chronosequence of deciduous forests in Wisconsin and Michigan. The chronosequence consisted of (1) four recently disturbed stands, including a clearcut and repeatedly burned stand (burn), a blowdown and partial salvage stand (blowdown), a clearcut with sparse residual overstory (residual), and a regenerated stand from a complete clearcut (regenerated); (2) four young aspen (Populus tremuloides) stands in average age of 10 years; (3) four intermediate aspen stands in average age of 26 years; (4) four mature northern hardwood stands in average age of 73 years; and (5) an old‐growth stand approximately 350‐years old. We fitted site‐based models and used continuous measurements of soil temperature to estimate cumulative soil respiration for the growing season of 2005 (days 133–295). Cumulative soil respiration in the growing season was estimated to be 513, 680, 747, 747, 794, 802, 690, and 571 g C m−2 in the burn, blowdown, residual, regenerated, young, intermediate, mature, and old‐growth stands, respectively. The measured apparent temperature sensitivity of soil respiration was the highest in the regenerated stand, and declined from the young stands to the old‐growth. Both, cumulative soil respiration and basal soil respiration at 10 °C, increased during stand establishment, peaked at intermediate age, and then decreased with age. Total soil carbon at 0–60 cm initially decreased after harvest, and increased after stands established. The old‐growth stand accumulated carbon in deep layers of soils, but not in the surface soils. Our study suggests a complexity of long‐term soil carbon dynamics, both in vertical depth and temporal scale.