比叶重及其与光合能力的关系

白桦、水曲柳、蒙古栎和红松四个树种各自的叶面积与叶干重具有显著的相关关系 ,比叶重存在着明显的季节变化 ,这种变化与其生长节律密切相关 ,同时反映出不同树种之间养分利用及贮藏方式存在着差异。三个阔叶树种及红松当年生叶的比叶重 ,生长季末高于生长初期 ;红松 1年生叶和 2年生叶 ,在生长初期的比叶重高于生长末期。四个树种在生长初期比叶重变化速度的不同 ,反映出树种间叶片发育过程存在差异。生长季树种比叶重平均值的排序为 :红松 >白桦 >水曲柳 >蒙古栎。水曲柳、蒙古栎以及红松 2年生叶的比叶重与光合能力表现出统计上的显著相关关系 ,相关曲线均为二次抛物线型 ,即比叶重过大或过小 ,光合能力都会降低。白桦和红松1年生叶的比叶重与光合能力的相关性很弱。

The Specific Leaf Weight and Its Relationship with Photosynthetic Capacity

There was significant relationship between the leaf area and leaf dry weight of four species of Betula platyphylla, Fraxinus mandshurica, Quercus mongolica and Pinus koraiensis, and the specific leaf weight (SLW) showed significant change with seasons. These variations were closely related with the growth rhythm and reflected the differences in nutrients utilization and storage patterns for different tree species. The SLW of annual leaves in the last stage of growing season was higher than that in the early stage of growing season for these four tree species, and the SLW of the leaves for 1and 2-year-old of Pinus koraiensis in the early stage of growing season was higher than that in the last stage of growing season. The differences in the changeable rate of SLW for these four tree species in the early stage of growing season reflected the differences in leaves development for different species. In growing season, the order of the average SLW was Pinus koraiensis>Betula platyphylla>Fraxinus mandshurica>Quercus mongolica. There was an illuminating statistical relationship between SLW of leaves and photosynthetic capacity for 2-year-old of Fraxinus mandshurica, Quercus mongolica and Pinus koraiensis, and the corresponding curves were parabola, namely, the photosynthetic capacity of leaves with too much or too little SLW would decrease. There was a weak relationship between the SLW and photosynthetic capacity for 1-year-old of Betula platyphylla and Pinus koraiensis.