Light regime and tree regeneration in scarified sites in forest stands

林分中的光照状况和树木再生

• 批准号: 08660170
• 负责人: SHIBUYA Masato
• 金额: $ 1.41万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08660170/
• 关键词: scarified site; light regime; tree; growth rate; seed dispersal; 林分種組成; 光条件

Light regime and stand strucuture of 4 natural stands regenerating on scarified sites in mixed forest stands with various canopy closures were invsetigated in the Uryu and Nakagawa Experimental Forests of Hokkaido University.Light regime was affected by shading from canopy and was spatially heterogeneous, ranging from less than 10% to approximately 100% in RLI,in each site. Light conditon under the canopy was estimated roughly as 15-30% in RLI,and it around the canopy edge as about 40%. RLI on the center of a canopy gap reached to more than 80%.Species composition and structure of a regenerating stand were also affected by canopy distribution. In a canopy gap, pioneer trees such as birches dominated, though late-successional trees such as oak and conifers were mixed with birches or were dominant on occasion under and around the canopy.Therefore, a regenerating stand was composed of small patches of various species composition and structure. Trees with seed dispersed by birds occurred frequently. Height growth decreased with reduced light condition. This tendency was extremely obvious in birch. It is possible that a mixed stand regerates on a scarified site with the canopy of overstory trees.

在北海道大学乌龙和中川实验林中，对不同树冠封闭度的混交林中的 4 个天然林分的光照状况和林分结构进行了研究。光照状况受到树冠遮蔽的影响，并且具有空间异质性，范围从较小到小于每个站点的 RLI 低于 10% 到大约 100%。 RLI中树冠下的光照条件估计约为15-30%，树冠边缘周围的光照条件约为40%。冠层间隙中心的RLI达到80%以上。更新林的物种组成和结构也受到冠层分布的影响。在树冠间隙中，先锋树（例如桦树）占主导地位，尽管后来演替的树木（例如橡树和针叶树）与桦树混合，或者有时在树冠下方和周围占主导地位。因此，再生林分由不同物种的小斑块组成组成和结构。鸟类传播种子的树木经常出现。身高增长随着光照条件的减少而下降。这种趋势在桦木中表现得极为明显。混合林分可能会在一片被树木覆盖的土地上重新生长。