Effects of wind and thermal conditions on timberline formation in central Japan: a lattice model
Effects of wind and thermal conditions on timberline formation in central Japan: a lattice model
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DOI：
10.1007/s11284-014-1129-2
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发表时间：
2014-01
影响因子：
2
通讯作者：
Koichi Takahashi
中科院分区：
文献类型：
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作者：
Koichi Takahashi
在日本中部，高大树种冷杉的分布上限为林线，矮松的分布上限为林线以上至山顶附近。我以前的研究表明，林线形成的主要原因是由于冬季强风造成的死亡率增加，而不是由于夏季温度低造成的低生长。本研究利用格子模型评估风速如何影响林线的形成，以及林线的高度是否因高温而向上移动。在整个海拔的风速增加降低了这两个物种的分布上限的海拔。相反，高温条件下生长期的延长使磷的分配上限增加。pumila，以及A. mariesii几乎不受生育期变化的影响。P. pumiladue的延长生长期的模型将是不现实的，因为P。普密拉已经分布到山顶附近。本研究的结论是A. mariesii是P.的上级竞争对手。在低海拔、低风速条件下，白皮松生长最好，而松树生长最差。pumilacan占主导地位，在较高的海拔，因为A. mariesii因冬季强风而遭受严重的机械破坏，即使在全球变暖造成的高温条件下，树带线的高度也不会向上移动。
The upper distribution limit of tall tree speciesAbies mariesiiis the timberline in central Japan, and dwarf pinePinus pumiladominates above the timberline to near the summit. My previous studies suggested that the main cause of the timberline formation is the increase in mortality due to strong wind in winter rather than low growth due to low summer temperature. This study evaluated how wind velocity affects timberline formation and if the altitude of timberline moves upward due to high thermal conditions, by using a lattice model. Increase in wind velocity throughout the altitude lowered the altitudes of upper distribution limits of the two species. On the contrary, prolonged growth period due to high thermal conditions increased the upper distribution limit ofP. pumila, and the upper distribution limit ofA. mariesiiwas hardly affected by the change of growth period. However, the upward shift of the upper distribution limit ofP. pumiladue to the prolonged growth period in the model would not be realistic becauseP. pumilahad already distributed up to near the summit. This study concludes thatA. mariesiiis a superior competitor toP. pumilaat low altitudes with low wind velocity, but dwarf pineP. pumilacan dominate at higher altitudes becauseA. mariesiisuffers severe mechanical damage due to strong wind in winter, and that the altitude of the timberline does not move upward even under high thermal conditions due to global warming.