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The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus >
No.42 (1995/12) >

 
Title :早生樹種同齢林分の成長モデルに関する比較研究(生物生産学科)
Title alternative :Comparative studies of growth models of selected even-aged fast growing tree species (Department of Bioproduction)
Authors :安里, 練雄
パレル, ジオスダド ア
篠原, 武夫
Authors alternative :Asato, Isao
Paler, Diosdado A.
Shinohara, Takeo
Issue Date :1-Dec-1995
Abstract :本研究は, 早生造林樹種の成長予測に資する目的でいくつかの成長モデル式の適応性について検討を試みたものである。7樹種(フィリピン3,沖縄3,九州1)について, 林分平均胸高直径, 平均樹高, ha当り立木幹材積を資料にミッチャーリッヒ, ゴンペルツ, ロジステック, 修正指数の各式について分析した。各々の式は係数を最小自乗法で算定して得た。各式の当該パラメタに観測値を代入してその理論値を算出し, 式の適応性を比較検討した。林齢や成長に関係するパラメタ等供試資料の範囲内においては, 得られたモデル式は相対的に有効と評価できるが, 総体的にミッチャーリッヒ式が最適であると言える。他の3式は成長過程を示すことはできても, ミッチャーリッヒ式ほど良好とは言いがたい。同様に算定されたモデルに基づいて, 各々の樹種についても比較を行った。フィリピンの供試樹種は沖縄, 九州の樹種に比べて成長が早い。これらの結果は, 得られたモデル式が林分成長予測システムを調製するための基礎として利用することに有効であることを示している。
Generally, stand growth is affected by stand age, site quality, stand density, timber management regime and other factors. Based on this reasoning, the study deals with the development of a system of equations for the growth prediction of important tree species. Given the data on the average stand dbh, height, and vol/ha an analysis of growth curves was made for the 7 fast growing tree species using the Mitscherlich, Gompertz, Logistic, and the Modified Exponential functions. The parameters of these corresponding equations were determined by the least squares method and respective growth equations were derived and developed. Subsequently, by substituting the observed values to the corresponding parameters, the theoretical growth values were calculated and compared. Within the normative range of units and measures of stand age and growth parameters, the growth models resulting from this study can be rated as relatively efficient. A critical review of these models revealed that, in general, the Mitscherlich was the most appropriate equation to describe the growth of the tree species. Although the other three functions had satisfactorily fulfilled the representation of the growth course, they were not as good as the Mitscherlich. Similarly, a comparison on the growth of the tree species was conducted based on the developed models. The species of the Philippines are relatively considered fast growing in contrast to the species of Japan. The results demonstrated that the developed models are worthwhile to be utilized as a basis for an integrated stand growth prediction system.
Type Local :紀要論文
ISSN :0370-4246
Publisher :琉球大学農学部
URI :http://hdl.handle.net/20.500.12000/3747
Citation :琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus no.42 p.67 -79
Appears in Collections:No.42 (1995/12)

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