報告書番号

U88047

タイトル（和文）

樹木年輪による環境影響評価手法の開発（１）マツの年輪幅の実態と基礎特性

タイトル（英文）

DEVELOPMENT OF ENVIRONMENTAL ASSESSMENT BY TREE RING (1) CHARACTERISTICS OF TREE RING WIDTH IN PINE TREE

概要 （図表や脚注は「報告書全文」に掲載しております）

本報告は，年輪による環境評価法の開発上必要な年輪の基礎特性を把握する観点より，６地域から４２６本のマツ（アカマツ，クロマツ）の採取と年輪測定を行い，１）年輪幅の範囲と頻度，２）最大年輪と最小年輪の性質，３）年輪時系列の変動特性を明らかにしたものである。年輪幅の範囲と頻度は，アカマツが範囲０．１－１６．２ｍｍ，モード１．０５－１．５０ｍｍの対数正規分布を示し，クロマツが０．０５－９．０５ｍｍ，モード１．０５－１．５０ｍｍの対数正規分布を示した。年輪幅の頻度分布は加齢に伴い正規分布→対数正規分布→Ｌ型分布の変化をたどることが推定された。最大年輪と最小年輪の出現は，前者が年齢４－１２年で多く現れる年齢に依存する特性を示し，後者が暦年に依存する特性を示した。年齢時系列の変動には，年齢１年目の狭い年輪から年輪１０年程度まで次第に幅が増加して最大に達し以後減少する加齢に伴う変動特性と，郡落構造に関係

概要 （英文）

TO DEVELOPE THE ENVIRONMENTAL ASSESSMENT METHOD USING TREE RING ANALYSIS,THE CHARACTERISTICS OF TREE RING WIDTH WERE STUDIED IN PINE TREES. SAMPLING TOTAL OF 426 TREES FROM 6 STANDS RANGED FROM TOHHOKU DISTRICT TO CHUGOKU DISTRICT OF HONSHU IN JAPAN,1)FREQUENCY DISTRIBUTION OF TREE RING WIDTH,2)NATURE OF MAXIMUM TREE RING AND MINIMUM TREE RING,3)CHRACTERISTICS OF TIME SERIES OF TREE RING WIDTH,WERE MADE CLEAR. FREQUENCY DISTRIBUTION OF TREE RING WIDTH IN PINUS DENSIFLORA AND P.THUNBERGII AT THE AVERAGED AGE OF 50 YEAR SHOWED A LOGARITHMIC NORMAL DISTRIBUTION WITH A MODE OF 1.05-1.50MM. PINUS DENSIFLORA SHOWED WIDER RANGE OF 0.1-16.2 MM THAN THAT (1.05-1.50MM) OF P.THUNBERGII. IT WAS INDICATED THAT FREQUENCY DISTRIBUTION CHANGES FROM A NORMAL DISTRIBUTION TO L-SHAPED DISTRIBUTION PASSING THROUGH A LOGARITHMIC NORMAL DISTRIBUTION ALONG WITH INCREASING AGE. THE MAXIMUM TREE RING,WHICH WERE DEFINED AS A WIDEST RING IN A TREE,HAD WIDTH OF 6.5MM +-3.5MM OF P.DENSIFLORA AND 6.5MM +-3.5MM IN P.THUNBEGII,AND SHOWED THE CHARACTERRISTIC TO APPEAR DEPENDING ON AGE. THE MINIMUM TREE RING WHICH WAS DEFINEDAS A NARROWEST TREE RING IN A TREE,SHOWED THE CHARACTERISTIC TO APPEARDEPENDING ON CALENDAR YEAR. AS FOR THE TIME SERIES OF TREE RING WIDTH,THE CHARACTERISTIC CHANGE PATTERN DEPENDING ON AGEING AND THE PATTERN DEPENDING ON FOREST STRUCTURE WERE OBSERVE.

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