報告書番号

483008

タイトル（和文）

石炭灰捨地に発達したマツ幼令林での生長調査

タイトル（英文）

YOUNG PINE FOREST DEVELOPED ON COAL ASH BASIN

概要 （図表や脚注は「報告書全文」に掲載しております）

石炭灰捨地に発達したマツ林について，地上部の生長特性および根系の発達状況を調べた。１）林分の令構造には特異的な特徴は存在しなかったが，立木密度は低くなっており，自生初期段階の定着がやや劣るものと推定された。２）地上部の相対生長関係の比較により，灰捨地のマツの樹形はずんぐりした形状をとり，枝の生長が促進されることが示された。３）樹高生長パターンには，明らかに対照区と異なるパターンが観察された。このパターン差から，石炭灰区においては初期（年令１～５年頃）生長が促進され，かつ，生長の鈍化時期が早められることが認められた。４）直径生長においても，生長の鈍化時期が早められる傾向が観察された。５）根系の発達状態には明らかに対照区と異なる特徴が認められた。石炭灰区の根系は覆土と石炭灰の境界層で主根がほぼ直角に曲り，石炭灰の中へは余り入っておらず，水平方向への側根の発達が顕著であった。

概要 （英文）

AN AGE STRUCTURE STAND DENSITY,RELATIVE GROWTH RELATIONSHIP,HEIGHT AND DIAMETER GROWTH PATTERN,AND ROOT SYSTEM WEREEXAMINED INSIDE YOUNG PINE STAND DEVELOPED ON A COAL ASH BASIN IN NORTHEASTERN JAPAN. 1.THERE WERE NO DIFFERENCES IN AGE STRUCTURE OF PINE FOREST BETWEEN ON ASH SOIL AND ON CONTROL STAND EXCEPT FOR LOWER ESTIMATED SURVIVAL RATE OF PIONEER SEEDLINGS ON ASH SOIL STAND. 2.STAND DENSITYOF PINE FOREST ON ASH SOIL STAND WAS LOWER THAN THAT ON CONTROL STAND PRESUMABLY BECAUSE OF LOWER SURVIVAL RATE OF SEEDLINGS. 3.A COMPARISON OF RELATIVE GROWTH RELATION OF PINE TREE FOR HEIGHT-DIAMETER IN LENGTH AND STEM-TOTAL,BRANCH-TOTAL,NEEDLE-TOTAL IN FLESH WEIGHT BASIS BETWEEN ON ASH SOIL AND CONTROL STAND REVEALED THAT PHENOTYPIC CHANGE WAS OCCURRING TOWARD MORE STOKY SHAPE OF MAIN STEM AND BRANCH GROWTH WAS ACCELELATED ON ASH STAND. 4.IT WAS OBSERVED THAT HEIGHT GROWTH PATTERN OF PINETREE ON ASH SOIL STAND WAS DIFFERENT FROM THAT ON CONTROL STAND.THE DIFFERENCE OF GROWTH PATTERN BETWEEN TWO STANDS INDICATED THAT HEIGHT GROWTH WAS ACCELELATED AT YOUNGER AGE STAGE OF 1 5 YEARS AND WAS RETARDED AT OLDER AGE STAGE OVER 7 YEARS ON ASH SOIL STAND. 5)AS FOR DIAMETER GROWTH PATTERN ALMOST THE SAME TREND WAS OBSERVED AS IN THE CASE OF HEIGHT GROWTH. 6.DISTRIBUTION OF ROOT SYSTEM OF PINE TREE ON ASH SOIL STAND WAS DISTINCTIVELY DIFFERENT FROM THAT ON CONTROL STAND.IN THE CASE OF ASH SOIL STAND A TAP ROOT BENT WITH A RIGHT ANGLE AT THE COVERED SOIL-ASH BOUNDARY AND ROOT SYSTEM DID NOT DISTRIBUTE INSIDE ASH LAYER.ALSO BIGGER LATERAL ROOTS DEVELOPED HORIZONTALLY TO FORM THE WIDER DISTRIBUTIONRANGE ON ASH SOIL STAND.

報告者

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