Modeling Soil Temperature Effects on In Situ Decomposition Rates for Fine Roots of Loblolly Pine
Modeling Soil Temperature Effects on In Situ Decomposition Rates for Fine Roots of Loblolly Pine
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DOI：
10.1093/forestscience/39.1.118
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发表时间：
1993-02
期刊：
影响因子：
1.4
通讯作者：
G. Ruark
中科院分区：
文献类型：
--
作者：
G. Ruark
研究了土壤温度与细根分解的关系。将含有火炬松幼苗根系的未受干扰的土芯在实验室中在田间持水量条件下在15°和25°C的恒定土壤温度下培养。一些幼苗根系被允许在室外原位分解，在那里记录土壤湿度和温度。将实验室和室外原位结果与清洗、风干并重新埋在网袋中的幼苗根的分解率进行比较。在15°和25°条件下，含细根和小主根的幼苗根系的分解速率分别为31%和44%，而仅细侧根的分解速率分别为57%和66%。在15° ~ 25°范围内，全根系和侧根的年平均Q-10 s分别为1.4和1.2。实验室培养结果被用来构建一个回归模型细根分解作为累积月平均温度的函数。该模型进行了验证，对数据的根系，被允许分解在外面原位。1年后，这种材料的分解是43%完成的整个根系和60%完成的根。从回归模型中准确预测了在不同时间间隔观察到的剩余重量。1年后，根埋袋显示类似的室外原位样品的重量损失。然而，它们的分解速率是线性的，而室外和培养箱原位样品遵循曲线衰减路径。SCI. 39（1）：118-129。
A study was conducted to quantify the relationship between soil temperature and fine root decomposition. Undisturbed soil cores containing root systems of loblolly pine seedlings were incubated in the lab under field capacity moisture conditions at constant soil temperatures of 15° and 25°C. Some seedling root systems were allowed to decompose in situ outside, where soil moisture and temperature were recorded. Laboratory and outside in situ results were compared to decomposition rates for seedling roots that were washed, air-dried, and reburied outside in mesh bags. Laboratory decomposition rates of the seedling root system, which contained fine laterals and a small taproot, averaged 31% and 44% weight loss annually, while annual rates of only the fine lateral root component averaged 57% and 66% loss of total weight at 15° and 25°, respectively. Average annual Q-10s of 1.4 and 1.2 were calculated between 15° and 25° for whole root systems and lateral roots alone. Lab incubation results were used to construct a regression model for fine root decomposition as a function of cumulative average monthly temperature. The model was validated against data on the root systems that were allowed to decompose in situ outside. Decomposition of this material after 1 yr was 43% complete for the whole root system and 60% complete for laterals. The observed remaining weight at various time intervals was accurately predicted from the regression model. After 1 yr, roots in the buried bags displayed a weight loss similar to the outdoor in situ samples. However, their decomposition rate was linear, whereas both outdoor and incubator in situ samples followed a curvilinear decay path. FOR. SCI. 39(1):118-129.