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Weed communities and its dynamics in forest plantations of Sugi(Cryptomeria japonica) at various densities

不同密度柳杉人工林杂草群落及其动态

基本信息

批准号：
03660148
负责人：
SAKURA Tsuguo
金额：
$ 1.15万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03660148/
关键词：
Sugi plantations Weed community Community dynamics Planting density Growth of planted trees Stand structure Annual change The southern part of Boso peninsula 立地環境雑草木群落の動態立木密度植物遷移植生パターン状態診断雑草木害造林植生パタ-ン育林

项目摘要

The study was conducted in the forest of Tokyo university in the southern part of the Boso peninsula, to study the weed vegetation and its dynamics in forest plantations of Sugi(Cryptomeria japonica D.DON) at various densities.Species compositions, structure, etc.of weed vegetation changing with years were investigated mainly in a young plantation of Sugi at various densities.At the same time, growth status of planted trees, and forest structure were examined.In a young Sugi-stand with 3 treatment plots(tree density plots of 2,500, 3,906, 6,944 trees per hectare respectively), tall-grass type's Susuki(Miscanthus sinensis ANDERSS) belong to Gramineae has become the most dominant species on 2nd-yr to 5th-yr old stands after planting in each plot.In both plots of the lowest and the middle densities, the coverage percentages of Susuki plants were judged from an annual changes, decreased markedly on and after 5th-yr-old in both plot stands become into 3m, 45% in the mean height and the mean coverage of Sugi planting trees.On the other hand, Susuki plants in the highest density plot decreased markedly in the stands on and after 3rd-yr-old stand become into 2m, 30% in the mean height and the mean coverage of Sugi planting trees.Consequently, in this survey area, when densities of Sugi planting trees were 6,944 trees or over trees per hectare, here showed that Susuki plants have a trend of decreasing markedly in earlier, younger year old stand(on and after 3rd-yr-old stand) after Sugi planting.From results in these vegetation survey, here could to catching an outline of the actual conditions for dynamics of weed vegetation in relations with tree densities in Sugi forest plantations in the southern part of Boso.

以房总半岛南部的东京大学森林为研究对象，对杉人工林杂草植被及其动态进行了研究（Cryptomeria japonica D.DON）的不同密度下的杂草群落，主要调查了不同密度下杉人工种植园杂草群落的种类组成、结构等随年份的变化，同时还调查了人工林的生长状况，在一个有3个处理样地的幼龄林中，（树木密度分别为每公顷2，500、3，906、6，944棵树），高草型铃木禾本科植物芒草（Miscanthus sinensis ANDERSS）在第2 ~ 5年成为最优势种，在最低密度和中等密度的两个样地中，从年变化来看，铃木的覆盖率在5年生时和5年生后都明显下降，在3 m以下，最高密度样地中，杉树在3年生林分达到2 m时，其平均高度和平均郁闭度显著下降，平均高度和平均郁闭度下降了30%。944株/公顷以上，表明杉林种植后，早、幼龄林（3年生林前后）的铃木植物有明显减少的趋势，从这些植被调查结果可以大致了解房总南部杉林杂草植被动态与树木密度关系的实际情况。