Winter water relations of timberline larch (Larix leptolepis Gord.) on Mt. Fuji
Winter water relations of timberline larch (Larix leptolepis Gord.) on Mt. Fuji
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富士山林线落叶松 (Larix leptolepis Gord.) 的冬季水关系
DOI：
10.1007/pl00009656
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
E. Maruta
中科院分区：
文献类型：
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作者：
E. Maruta
落叶松（Larix leptolepis）的krummholz垫是南坡林线过渡带上限（2500 m）附近的主要生长类型。日本富士。在东南坡，由于最近的火山爆发，树线降低到1600米。对海拔2500 m和1600 m的落叶松林线带冬季干燥化的程度和原因进行了比较研究。树皮磨损，由于风吹细火山砾石造成的树皮抗水分流失的下降，并导致严重的干燥损害，当年拍摄的krummholz落叶松在1986 - 87年的冬天在2500米，而磨损拍摄在1600米保持高含水量在两个冬天。 在1985 - 86年冬季，2500米处的克鲁姆霍尔茨落叶松枝条没有发生树皮磨损，保持了较高的含水量。 拍摄表面的实验磨损导致在每个海拔相似的结果。因此，在2500米的落叶松林线，风吹细火山砾石的磨损是造成冬季干燥损害和krummholz形成的主要因素。根据田间试验，两个海拔高度的水运动到非磨损的枝条的估计量是相同的。在2500 m处，水分向磨损枝条的移动小于向未磨损枝条的移动，而在1600 m处，情况相反。在2500米处，对磨损枝条的供水有限，不足以补偿水分损失。2500 m处供水有限的原因可能是木质部栓塞。
A krummholz mat of larch,Larix leptolepis, is the predominant growth form near the upper limit (near 2500 m) of the timberline ecotone on the south slope of Mt. Fuji, Japan. On the south-eastern slope, the tree line is lowered to 1600 m because of the last volcanic eruption. The extent and causes of winter desiccation were compared in timberline larch between 2500 m and 1600 m elevation over two winters. Bark abrasion due to wind-blown fine volcanic gravels caused a decrease in bark resistance to water loss and resulted in severe desiccation damage to current-year shoots of krummholz larches in the winter of 1986 – 87 at 2500 m, whereas abraded shoots at 1600 m maintained high water content during both winters. In the winter of 1985 – 86, shoots of krummholz larches at 2500 m did not experience bark abrasion and high water contents were maintained. Experimental abrasion of shoot surfaces resulted in similar results at each elevation. Thus, in timberline larch at 2500 m, abrasion by wind-blown fine volcanic gravels is the primary factor causing winter desiccation damage and krummholz formation. Based on field experiments, the estimated amount of water movement to non-abraded shoots was the same for the two elevations. At 2500 m, water movement to abraded shoots was less than to non-abraded shoots, but the reverse situation was noted at 1600 m. Water supply to abraded shoots at 2500 m was limited and insufficient to compensate for water loss. A cause of limited water supply at 2500 m may be xylem embolism.