Mid-successional stand dynamics in a cool-temperate conifer-hardwood forest in northern Japan.
Mid-successional stand dynamics in a cool-temperate conifer-hardwood forest in northern Japan.
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日本北部冷温带针叶阔叶林的中期演替动态。
DOI：
10.1007/s11258-010-9781-2
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发表时间：
2010
期刊：
影响因子：
1.7
通讯作者：
K.
中科院分区：
文献类型：
--
作者：
Takahashi;K.
在日本北方冷温带针叶阔叶林中，对林分动态进行了13年的研究。共记录了30种阔叶树种和一种针叶树种，冷杉，大于1.5厘米的胸径。林分总密度在开始时为1677株ha− 1，在研究期间减少到1184株ha−1（减少30%），但林分总断面积几乎不变（约49 m2 ha −1）。总密度的大幅下降主要是由于树苗死亡和不经常补充。随着时间的推移，新梢数量逐渐减少，而枯树数量基本不变。小树的死亡原因主要是受高大树木的抑制。胸径频率分布的偏度因树种而异。较少偏斜的频率分布（即，不耐荫的物种，如杨和桦，表现出更偏的频率分布（即，大量的树苗）被耐荫的物种，如槭和日本紫椴。在调查期间，随着密度的降低，大部分树种的胸径频率分布向偏态较小的方向变化。耐荫性等级与密度、偏度呈显著正相关，与平均胸径呈显著负相关。偏度也与招聘率呈正相关。此外，耐荫性等级与种子大小呈正相关。这些结果表明，不耐荫的物种再生后立即干扰广泛传播的小种子，但他们的招聘后中断。与此相反，耐荫的物种能够补充，即使在停止招募的不耐荫的物种，但遭受严重的死亡率，由于随着林分发展的进展，越来越多的阴影。本研究表明，林分仍在发展中，与变化的物种组成和大小结构，和物种的耐荫性和种子大小的差异是很重要的林分结构的变化。
Stand dynamics was studied over 13 years in a cool-temperate conifer-hardwood forest, northern Japan. A total 30 hardwood species and one conifer,Abies sachalinensis, larger than 1.5 cm DBH were recorded. The total stand density was 1677 trees ha−1at the beginning, decreasing to 1184 trees ha−1(30% reduction) over the study period, but the total stand basal area was almost unchanged (about 49 m2ha−1). This large reduction in total density was mainly due to the death of saplings and infrequent recruitment. Number of recruits gradually decreased with time, while that of dead trees was constant. Cause of death of small trees was mainly due to suppression by tall trees. Skewness of the DBH frequency distribution varied among the species. A less skewed frequency distribution (i.e., few number of saplings) was shown by shade-intolerant species such asPopulus maximowicziiandBetula maximowicziana, and a more skewed frequency distribution (i.e., large number of saplings) by shade-tolerant species such asAcer monoandTilia japonica. DBH frequency distribution changed to less skewed patterns with reduction of density in most species during the census period. Rank of shade tolerance positively correlated with tree density and skewness, and negatively correlated with mean DBH. Skewness also positively correlated with recruitment rates. Furthermore, rank of shade tolerance positively correlated with seed size. These results suggest that shade-intolerant species regenerated immediately after disturbances by wide dispersal of small seeds, but their recruitment was interrupted after that. By contrast, shade-tolerant species were able to recruit even after the ceasation of recruitment of shade-intolerant species, but suffered severe mortality due to the increasing shading with the progress of stand development. This study suggests that the stand is still developing, with changes in species composition and size structure, and that species differences in shade tolerance and seed size are important for the stand structural changes.