東京大学農学生命科学研究科
東京大学農学生命科学研究科附属北海道演習林
Graduate School of Agriculture and Agricultural Sciences, The University of Tokyo
Shibiutan Forester Office, Esashi District Forest Office
The Tokyo University Forest in Hokkaido, The University of Tokyo
抄録
A-horizon windrowing, removing the entire A-horizon soil (both A1- and A2-horizons), is a method of site preparation to initiate natural regeneration of Yezo spruce (Picea jezoensis (SIEB. et ZUCC.) CARRIERE) in the boreal forests of Hokkaido. Soil properties in an area treated with A-horizon windrowing and in a non-disturbed area were compared 15 years after the soil treatment. In the treated areas, the (A1)- and (A2)-horizons were much thinner than the A1- and A2-horizons in the non-disturbed areas. Minimum air capacity, coarse pore space, and the water percolation rate of the upper horizon soil in the non-disturbed area were greater than those of the upper horizon soil in the treated area. Concentrations of total C, mineralizable soil N, and total N in the (A1)- and (A2)-horizons in the treated areas were much lower than those in the A1- and A2-horizons in the non-disturbed areas, respectively. There were no clear differences in the concentration of plant available P, exchangeable K, exchangeable Ca, exchangeable Mg, and CEC between the soil in the non-disturbed areas and the treated areas. Although an A-horizon development process had been taking place, it would take much longer than 15 years before top soil which is similar to the original (including the thickness of the horizon) is developed again in the areas treated with A-horizon windrowing.
北海道の亜寒帯林では，エゾマツ（Picea jezoensis (SIEB.et ZUCC.) CARRIERE）の天然更新を図るため，A層（A1層とA2層）を除去する地掻きが行われることがある。A層除去区と土壌未攪乱区において，地掻き15年後の土壌の理学性及び化学性を比較した。A層除去区の（A1）および（A2）層の厚さは，土壌未攪乱区のA1およびA2層のものよりも小さかった。表層土についてみると，気相及び最小容気量，粗孔隙量，透水能については，A層除去区のもののほうが土壌未攪乱区のものよりも低かった。A層除去区における全炭素濃度および全窒素濃度，無機化可能な窒素濃度は，土壌未攪乱区のものよりも低かった。反対に，可給態リン酸及び交換性カリウム，交換性カルシウム，交換性マグネシウム，陽イオン交換容量（CEC）については，土壌未攪乱区とA層除去区の間で明確な差はみられなかった。A層除去区においては，A層除去後土壌の生成が進みつつあったが，（土壌層の厚さも含めて）もととおなじようなA層土壌が発達するようになるまでには，15年よりもはるかに長い期間が必要であると考えられた。
雑誌名
東京大学農学部演習林報告
巻
95
ページ
247 - 255
発行年
1996
ISSN
03716007
書誌レコードID
AN00162451
日本十進分類法
610
出版者
東京大学大学院農学生命科学研究科附属演習林
出版者別名
The Tokyo University Forests
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Soil Properties 15 Years after A-Horizon Windrowing in Boreal Forests of Hokkaido : A case study in the Tokyo University Forest in Hokkaido
esrh095007.pdf
(674.98KB)
