Soil CO2 efflux in loblolly pine (Pinus taeda L.) plantations on the Virginia Piedmont and South Carolina Coastal Plain over a rotation-length chronosequence
Soil CO2 efflux in loblolly pine (Pinus taeda L.) plantations on the Virginia Piedmont and South Carolina Coastal Plain over a rotation-length chronosequence
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DOI：
10.1007/s10533-004-0566-3
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发表时间：
2005-03
期刊：
影响因子：
4
通讯作者：
C. Gough;J. Seiler;P. Eric;Wise Man;Christopher A. Maier
中科院分区：
文献类型：
--
作者：
C. Gough;J. Seiler;P. Eric;Wise Man;Christopher A. Maier
我们测量了位于弗吉尼亚山前（VA）和南卡罗莱纳海岸平原（SC）的火炬松林分（Pinus taedaL.）的土壤表面二氧化碳通量（Fs），以评估气候、生产力和文化实践对管理的火炬松生态系统的影响。采用重复时间序列方法研究了林龄对fs的影响，其中调查了种植后1至25年的林龄。使用封闭动态系统对VA和SC站点的土壤co2外排进行了一年多的测量。使用多元线性回归来评估f相关性，并检查候选解释变量与f之间的关系。土壤温度（前10 cm）是两个地点的主要相关因子。我们观察到fsin VA林分的年龄效应为正，而fsin SC林分与年龄没有关系。由于树冠闭合导致土壤温度降低，以及异养型碳基质库的减少，年土壤碳外排随林龄的增长而下降。1年林分和20年林分的年估算外排量分别为16.7 ~ 13.2 Mg C ha - 1。相比之下，VA林分的年土壤C外排随着林分年龄的增长而增加，这与林分年龄与f呈正相关，这可能与根呼吸对总通量的贡献增加有关。在VA林分中，1年林分和20年林分的外排估算值分别为7.6 - 12.3 Mg C ha - 1。这些结果表明，在估算碳收支时，需要进一步考虑森林管理和区域内变化对土壤碳外溢的影响。
We measured soil surface CO2efflux (Fs) in loblolly pine stands (Pinus taedaL.) located on the Virginia Piedmont (VA) and South Carolina Coastal Plain (SC) in efforts to assess the impact climate, productivity, and cultural practices have onFsin the managed loblolly pine ecosystem. The effect of stand age onFswas examined using a replicated chronosequence approach in which stands ranging from 1 to 25 years since planting were investigated. Soil CO2efflux was measured on both VA and SC sites for over a year using a closed dynamic system. Multiple linear regression was used to evaluateFscorrelates and examine the relationship between candidate explanatory variables andFs. Soil temperature (top 10 cm) was the major correlate withFson both locations. We observed a positive age effect onFsin VA stands and no relationship between age andFsin SC stands. Annual soil C efflux declined with stand age in SC due to both reductions in soil temperatures as crown closure occurs and a diminishing heterotrophic C substrate pool. Annual estimated efflux ranges from 16.7 to 13.2 Mg C ha−1for 1 and 20-year-old stands, respectively. In contrast, annual soil C efflux increased with age in VA stands as a result of the positive relationship between stand age andFs, which appears to be related to an increase in the contribution of root respiration to totalFsover time. In VA stands, efflux estimates range from 7.6 to 12.3 Mg C ha−1for 1 and 20-year-old stands, respectively. These results demonstrate the need to further consider the impact forest management and within-region variability have on soil C efflux over time when estimating C budgets.