Land-use conversion effects on CO2 emissions: from agricultural to hybrid poplar plantation
Land-use conversion effects on CO2 emissions: from agricultural to hybrid poplar plantation
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DOI：
10.1007/s11284-007-0420-x
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发表时间：
2008-05
影响因子：
2
通讯作者：
D. Saurette;D. Saurette;Scott X. Chang;B. Thomas
中科院分区：
文献类型：
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作者：
D. Saurette;D. Saurette;Scott X. Chang;B. Thomas
森林砍伐等土地利用变化被认为是温室气体排放增加的主要原因之一，而通过植树造林项目进行的可核查的碳封存有资格获得《京都议定书》规定的碳信用。研究了农用地(种植大麦)改种杂交杨(杨树×青杨×青杨)对CO_2排放的短期影响。沃克)种植园在艾伯塔省北部的帕克兰地区，那里正在大面积种植杂交杨树。二氧化碳排放量的测量采用静态气室法。大麦和沃克小区在土壤温度、体积含水率和土壤呼吸速率方面没有发现差异。2005年大麦和沃克样地的土壤平均呼吸速率分别为1.83m±0.19(μmolCO2m−2s−1)和1.89m±0.13mgmolCO2m。然而，大麦小区的生物量产量较高，这表明农业土地利用系统具有更强的固定大气CO2的能力。土地利用系统的碳平衡估计为大麦地块的小净收益(在考虑秸秆和谷物收获前)0.03±0.187 mg C/ha−1年−1和3.35m g C/ha−1年−1的净损失3.35t±0.080 mg C/ha/hm2。从长远来看，我们预计，随着树木变得更大，净初级生产力增加，杂交杨树人工林将成为净碳汇。
Land-use changes such as deforestation have been considered one of the main contributors to increased greenhouse gas emissions, while verifiable C sequestration through afforestation projects is eligible to receive C credits under the Kyoto Protocol. We studied the short-term effects on CO2emissions of converting agricultural land-use (planted to barley) to a hybrid poplar (Populusdeltoids×Populus×petrowskyanavar. Walker) plantation in the Parkland region in northern Alberta, where large areas are being planted to hybrid poplars. CO2emissions were measured using a static gas chamber method. No differences were found in soil temperature, volumetric moisture content, or soil respiration rates between the barley and Walker plots. The mean soil respiration rate in 2005 was 1.83 ± 0.19 (mean ± 1 SE) and 1.89 ± 0.13 μmol CO2m−2s−1in the barley and Walker plots, respectively. However, biomass production was higher in the barley plots, indicating that the agricultural land-use system had a greater ability to fix atmospheric CO2. The C balance in the land-use systems were estimated to be a small net gain (before considering straw and grain removal through harvesting) of 0.03 ± 0.187 Mg C ha−1year−1in the barley plots and a net loss of 3.35 ± 0.080 Mg C ha−1year−1from the Walker poplar plots. Over the long-term, we expect the hybrid poplar plantation to become a net C sink as the trees grow bigger and net primary productivity increases.