森林立地学会誌 森林立地38(2).1996.98〜108
アカマツ枯死木樹幹流が土壌に与える影響
藤 本 浩 平・酒 井 佳 美・西 村 武 二・有 光 一 登
高知県香美郡香我美町のアカマツ枯損林で，樹幹流が土壌に与える影響について調査した。アカマツ健全木樹幹流，アカマツ枯死木樹幹流，林外雨を1993年3月から1994年2月までの1年間採取し，樹幹周辺の表層土壌を深さ別に3層で採取し．それぞれ化学性を調べた。
1）樹幹流，林外雨のpHは，林外雨＞健全木＞衰弱木＞枯死木となった。
2）樹幹流，林外雨の溶存成分濃度は，NO3-N，NH4-Nは林外雨≒健全木≒衰弱木≒枯死木，
PO4-Pは林外雨≒健全木＜衰弱木＜枯死木，Naは林外雨＜健全木≒衰弱木≒枯死木，Cl，Ca，
Mg，Kは林外雨＜健全木 ＜衰弱木＜枯死木となった。
3）樹幹流のPO4-PとKは，健全木と枯死木の濃度の差が著しく，また，健全木が衰弱，枯死
すると濃度が高くなった。
4）樹幹基部土壌は，樹間部と比較してpH（H20）が低く，交換性塩基含有量が多かった。
5）枯死木の樹幹基部土壌は3層ともKが多いという傾向が見られた。
Kouhei
FUJIMOTO, Yoshimi SAKAI, Takeji NISHIMURA and Kazuto ARIMITSU : Influence of Stemflow of Dead Japanese red
pine (Pinus densflora Sieb. et Zucc.) on Soil Properties. Jpn. J. For.
Environment 38, 98-108, 1996
Influence of
stemflow on soil properties was investigated in a Japanese red pine (Pinus densiflora Sieb. et zucc.) stand located in Kagamicho, Kochi
Prefecture.
For chemical
analysis, rainwater and stemflow of sound, weakened, and dead trees were
collected from March l993 to February 1994 and soils in 4×4m area around stems were sampled at 3
different depths at every crossing of 0.5m horizontal interval grid.
The
experiment found out the following results:
1 ) The pH values of water samples were
higher in the order of rainwater>stemflow of sound
tree > of weakened tree > of dead tree.
2 ) Weighted mean concentration of
elements in water during whole study period were as
follows: NO3-N and NH4-N:
rainwater≒stemflow of sound
tree≒of weakened tree≒of
dead tree; PO4-P:
rainwater≒stemflow of sound
tree<of weakened tree<of dead tree; Na:
rainwater<stemflow of sound
tree≒of weakened tree≒of dead tree; Cl, Ca, Mg and K:
rainwater<stemflow of sound
tree<of weakened tree<of dead tree.
3 ) Concentrations of PO4-P
and K in stemflow of dead trees were greatly higher than those
of sound trees. The
concentrations were getting higher after the trees died.
4 ) The soil close to the base of stem was
lower in pH(H20) and higher in exchangeable
cations than the soils between
stems.
5) The concentration of exchangeable K
of the soil close to the base of dead stem was
remarkably high through 3 layers
of depth.