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Study on histories of old-growth forests and disturbances to them by fine scale pollen analysis of small hollows.

通过小空洞的精细花粉分析研究古老森林的历史和对它们的干扰。

基本信息

批准号：
06660196
负责人：
TAKAHARA Hikaru
金额：
$ 1.28万
依托单位：
Kyoto Prefectural University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

项目摘要

Pollen and charcoal fragment data from small hollows made clear histories of forests and disturbances to them in the two old-growth forests, Odaigahara, Nara Prefecture and Ashiu, Kyoto Prefecture, western Japan. This study indicates that pollen analysis is useful for the study of the forest dynamics.1. Linear regression analysis was used to analyze a relationship between pollen percentage from surface layr of soil under a canopy and tree percentage in the two old-growth forests. These results were used to interpret fossil pollen assemblages from small hollows as a record of stand-scale forest changes.2. Comparison of pollen data from three forest hollows in a beech-fir forest at Nanatsuike in Odaigahara indicated forest dynamics for the last 1300 years. In the early stage, Chamaecyparis obtusa percentage in the forest was higher than that at present. A gap formation at about 300 years ago was recognized near one hollow in this beech-fir forest. Deciduous oak trees invaded into this gap. Also, a tree of deciduous oaks near the hollow was 300 years old based on its tree ring. Charcoal fragments that increased at same time indicated that the cause of the formation of the gap was possibly a small fire by lightning.3.A spruce forest at Masakigahara in Odaigahara has maintained for about 1000 years. Before then, spruce was rare in the forest that was dominated by deciduous oak.4.Pollen analysis of a core from the Chojidani Moor in Ashiu made clear that Crytomeria japonica was a forest dominant from 1000 yr.BP.to 500 yr.BP.Pollen accumulation rate of Cryptomeria in this period was almost equal to that of Cryptomeria forests at present. Since about 500 years ago, trees of secondary forest elements such as deciduous oak and charcoal fragments increased. These are associated with man-induced disturbances.

花粉和木炭碎片的数据，从小空洞清楚的历史，森林和干扰，他们在两个古老的森林，奈良县，小代原和芦，京都县，日本西部。研究表明，花粉分析对森林动态的研究具有重要意义.采用线性回归分析方法，分析了两种古老林冠下土壤表层花粉含量与乔木率的关系。这些结果被用来解释化石花粉组合作为林分尺度森林变化的记录。比较花粉数据，从三个森林空洞的山毛榉冷杉林在七池在Odaigahara表明森林动态在过去的1300年。在早期阶段，钝头山慈菇在林分中所占的比例比现在高。在这片山毛榉冷杉林的一个山谷附近，人们发现了大约300年前形成的一个缺口。落叶橡树侵入了这个缺口。此外，根据树木年轮，山谷附近的一棵落叶橡树有300年的历史。同时增加的木炭碎片表明形成差距的原因可能是一个小的闪电火灾。3.在大原Masakigahara云杉林保持了约1000年。4.对芦尾长谷摩尔样柱的花粉分析表明，从1000年yr.BP.to500年BP，日本柳杉（Crytomeriajaponica）一直是森林的优势种，这一时期柳杉的花粉积累速率与现今柳杉林的花粉积累速率相当。从大约500年前开始，落叶栎和木炭碎片等次生林成分的树木增加。这些都与人为干扰有关。