权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Carbon flux in soil and plant-root compartments in the matter recycling system of secondary forests

次生林物质循环系统中土壤和植物根区室的碳通量

基本信息

批准号：
06660172
负责人：
HASHIMOTO Ryoji
金额：
$ 1.28万
依托单位：
Iwate University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

The carbon dioxide release from mineral soil layr was measured by using alkali solution in young Cryptomeria japonica stands. The CO_2 release changed seasonally in accordance with the fluctuation in soil temperature, being around 2.2 the Q_<10> values. The amount of CO_2 release largely differed with measurement places, where root biomass and root composition with its diameter in mineral soil layr at each place had a great influence. The linear multiple regression model, R=a_0+a_1w_1+a_2w_2+a_3w_3, was quite useful to divide the total CO_2 release (R) into those from mineral soil and root systems. Here w_1 to w_3 in the equation stand for root weights for different diameter classes. The respiratory amount by root system was estimated to occupy more than 60% of the total CO_2 release.The respiration by root system was investigated in relation to growth and respiration of the above-ground organs in seedings of three coniferous species, Pinus densiflora, Lalix leptolepis, and Cryptomeria japonica. The linear relationship was recognized in each species between above-ground and under-ground respirations through various growth stages. Gradient of the regression line, implying ratio of above-ground respiration against under-ground one, was significantly higher in C.japonica and lower inP.densiflora. These differences were considered to result from specific properties with respect to internal development of root tissues. Although additional works are needed to clarify that simple relationships are observed in more developed stages in individual growth, the results obtained here are very suggestive in examining much better estimation methods of the under-ground respiration in forest stand level.

用碱溶液法测定了柳杉幼林矿质土层二氧化碳释放量。CO_2释放量随土壤温度的变化而呈季节性变化，其Q值在2.2左右<10>。CO_2释放量因测点不同而有较大差异，其中各测点矿质土层根系生物量、根系组成及其直径对CO_2释放量影响较大。多元线性回归模型R=a_0+a_1w_1+a_2w_2+a_3w_3可用于划分矿质土壤和根系CO_2释放总量（R）。其中，方程中的w_1至w_3代表不同直径级的根重量。通过对赤松（Pinus densiflora）、日本落叶松（Lalix leptolepis）和柳杉（Cryptomeria japonica）3种针叶树种的根呼吸与地上部器官生长和呼吸的关系进行研究，结果表明，根呼吸量占CO_2释放总量的60%以上。在不同的生长阶段，地上和地下呼吸之间的线性关系被认为是在每个物种。回归线的梯度，即地上呼吸与地下呼吸的比值，在日本石楠中显著较高，而在密花杨中较低。这些差异被认为是由根组织内部发育的特定特性引起的。虽然需要更多的工作来澄清，简单的关系，观察到在更发达的阶段，在个人的成长，这里得到的结果是非常有启发性的检查更好的估计方法的林分水平的地下呼吸。