| Creator |
|
|
|
|
|
|
|
|
|
|
|
| Language |
|
| Publisher |
|
|
|
| Date |
|
| Source Title |
|
| Vol |
|
| First Page |
|
| Last Page |
|
| Publication Type |
|
| Access Rights |
|
| JaLC DOI |
|
| Abstract |
九州山地奥地林に属する九州大学宮崎地方演習林では,広葉樹天然林からスギ･ヒノキの人工林へ林種転換を図る一方式として細胞式皆伐作業法が1978年度から適用されている.最近,それらの人工林の本数減少が顕著になり,そのために不成績造林地化の傾向が見られる.そこで,それらの人工林の成育状態を調査し,今後の取り扱い上の問題点について若干の検討を試みた.調査対象は,本作業法試験林のうち1979年度から1987...年度植栽までの6伐区であり,まず,成育状態を解析し,次いで,スギ･ヒノキの造林適地の判定を行い,さらに造林木の残存率と樹種,植栽年度及び立地因子との関係を数澄化Ⅰ類によって解析した.適地判定の結果によると,本適用林は地位2及び3等が多く分布するものの潜在的林地生産力を有し,成林可能であることが明らかとなった.成育状態の解析結果によると,伐区により本数減少は著しく異なっており,79年度及び81年度伐区では成林の可能性があるものの,83,84,87年度伐区では部分的に成林の可能性があり,85年度伐区では成林の見込みはないことが明らかとなった.関係解析の結果から,不成績造林地化の主因はシカの食害であって,一部気象害の可能性も考えられた.今後,林業生産を行うには,シカの食害に対する防護策が不可欠であるが,既に不成績造林地化した林分は,シカへの十分な対策を講じつつ何らかの更新手段によって,森林状態へ誘導することが不可欠である.
The clearcutting system in the blocks surrounded by shelter belts with sugi (Clyptomeria jajJonica D,Don) and hinoki (Chamaecyparis obtusa Endl.) plantations has been applied in the Kyushu university forest in Miyazaki, located in mountainous regions in Kyushu island, since 1978. The number of planted trees has decreased so largely that many plantations have resulted in unsuccessful stands. The purpose of this paper is to discuss the problems of treatment for the stands. The subjects of investigation are the 6 blocks from 1979 to 1987 in the experimental forests of this working system. The procedures of study are as follows: 1) analysis of the condition of plantations 2) assessment of site productivity 3) analysis of the relationships between the survival rates of the planted trees and the factors concerned such as species, the planted years, and the topographic factors by using the quantification method Ⅰ. From the results obtained, though the site productivity for the plantation is not poor, the extents of the decrease of the survival trees number were different between the blocks and some of the plantations result in the unsuccessful stands. The largest cause for the preceding decrease was deer (Cervus nippon nippon Temminck) damage, and partially meterological disasters. The protection methods for the deer damage hence are indispensable for forestry in future. It is the matter to be soleved for the time being that the unsuccessful stands should recover by some regeneration manner with provision for the damage.show more
|
Export Mendeley
p047