Influence of forest clear-cutting on the thermal and hydrological regime of the active layer near Yakutsk, eastern Siberia
Influence of forest clear-cutting on the thermal and hydrological regime of the active layer near Yakutsk, eastern Siberia
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DOI：
10.1029/2005jg000039
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发表时间：
2005-10-26
影响因子：
3.7
通讯作者：
Fukuda, Masami
中科院分区：
文献类型：
--
作者：
Iwahana, Go;Machimura, Takashi;Fukuda, Masami
[1] 在成熟的落叶松林和试验性采伐中对活动层的热和水文条件进行了研究，以明确活动层的热量和水收支特征，并评估皆伐对多年冻土和活动层条件的影响。皆伐强化地面解冻，一年后林地与采伐地活性层厚度差异达14厘米。森林土壤含水量急剧下降，而采伐处土壤含水量在砍伐后的第一个解冻季节保持不变。尽管割伐时地热通量继续增加（割伐后1年和2年5月至8月站点间总量差异分别为44和69 MJ/m(2)），但活动层条件的显着变化仅限于第一个解冻季节。 2年和3年各位点之间活性层厚度的相应差异分别为16厘米和14厘米。扰动后第二次春季大量冰的热惯性效应抑制了切换点最大融雪深度的进一步增加。这表明在这个连续的多年冻土带中，森林扰动后活动层厚度存在自我保持机制。
[1] Thermal and hydrological conditions in the active layer were investigated at a mature larch forest and an experimental cutover, to clarify the characteristics of heat and water budget in the active layer and to assess the influence of clear-cutting on permafrost and active layer conditions. Clear-cutting enhanced ground thawing and the difference in the active layer thickness between the forest and the cutover after 1 year was 14 cm. The soil water content drastically decreased at the forest, while that at the cutover was retained during the first thaw season after clear-cutting. Although the ground heat flux continued to increase at the cutover (the difference in the total amounts between sites from May to August were 44 and 69 MJ/m(2) in 1 year and 2 years after the clear-cutting, respectively) marked changes in the active layer conditions were limited only to the first thaw season. The correspondent differences in the active layer thickness between the sites were 16 and 14 cm in 2 years and 3 years, respectively. Further increases in the maximum thaw depth at the cutover site were inhibited by the thermal inertial effect of the larger amount of ice in the second spring after disturbance. This suggests a self-retention mechanism of the active layer thickness after forest disturbance in this continuous permafrost zone.