森林立地学会誌 森林立地41（2），1999，67〜76
Jpn.J.For.Environment41（2），67-76 1999
馬尾松林の皆伐・火入れ施業が土壌の理化学性に及ぼす影響
劉 発茂・生原喜久雄
中国で実施されている皆伐・火入れ地拵えが地力に及ぼす影響を明らかにするために，中国福建省の馬尾松人工林の斜面の上，中，下部に皆伐前および管伐・火入れ後2年間の土壌の理化学的性質の経時変化を調査した。皆伐・火入れ地の月平均地表面温度は皆伐を行わなかった馬尾松林地よりも7月で3.0℃，8月で5.9℃高かった。雨量の少ない11月〜1月には，皆伐・火入れ地の表層土壌のpFは3.7〜4.2となり，馬尾松林地より明らかに高かった。また0〜20cm層での毛管水量は馬尾松林地の10〜30％と非常に少なかった。表層土壌のpHは火入れ2週間後に約1上昇したが，1年目で低下し，2年後は皆伐前のpHよりやや下回った。火入れ後に増加した土壌中の無機態Nおよび塩基は1年目で急激に減少し，2年後にはほとんど消失した。皆伐・火入れ後の2年間で消失した総N量（皆伐で残された有機物に含まれるN量と土壌中のNの損失量の和）は斜面上部で417kg・ha-1，斜面中部で619kg・ha-1，斜面下部で694kg・ha-1と推定された。短伐期で火入れ地拵えを繰り返した場合，土壌の物理的性質の悪化および養分損失，特にNの欠乏が生じると推定された。
Famao Liu and Kikuo Haibara: Effects of
clear-cutting and burning on soil physical and chemical properteis in a Pinus massoniana plantation. Jpn.
J. For. Environment 41, 67-76, 1999.
An investigation was performed on the
changes in physical and chemical properties of soil in a pinus massoniana (masson pine) plantation after clear-cutting and
burning (CCB) on upper, middle and lower slopes in Fujian Province, China. The
monthly mean temperature of the CCB site at 0 cm soil depth was respectively
3.0℃ and 5.9℃ higher in July and August than in the
masson pine stand (control). The pF of surface soil ( 0-10cm) after CCB ranged
from 3.7 to 4.2 during low rainfall from November to January, which is clearly
higher than that of the control. The volume of capillary water at the CCB site
was very low, and was 10-30% of the control. The increments of pH at the
surface soil caused by CCB after two weeks about one, and they sharply
decreased after one year. After two years it was a little lower than that
before CCB. The increments of mineralized nitrogen and cation in the soil
caused by CCB decreased sharply during the first year, and were basically equal
to those of the control after two years. The loss of total nitrogen caused by
CCB (including the loss of nitrogen in soil and the residual organic matter)
was estimated to be 417kg ha-1 at the upper slope, 619kg ha-1
at the middle slope and 694kg ha-1 at the lower slope. If CCB
preparations are repeated in short rotation, the physical and chemical
properties of the soil will deteriorate, especially with a deficiency of
nitrogen.