SHOOT DYNAMICS OF PINUS-PUMILA IN RELATION TO ALTITUDINAL AND WIND EXPOSURE GRADIENTS ON THE KISO MOUNTAIN-RANGE, CENTRAL JAPAN
SHOOT DYNAMICS OF PINUS-PUMILA IN RELATION TO ALTITUDINAL AND WIND EXPOSURE GRADIENTS ON THE KISO MOUNTAIN-RANGE, CENTRAL JAPAN
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DOI：
10.1093/treephys/13.1.41
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发表时间：
1993-07-01
期刊：
影响因子：
4
通讯作者：
KAJIMOTO, T
中科院分区：
文献类型：
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作者：
KAJIMOTO, T
日本高山石松（Pinus pumila Regel.）在日本中部木曾山脉的六个不同海拔和坡度的地点进行了调查。芽遵循类似的增长模式，在所有网站，目前的芽迅速拉长在6月和7月，目前的针增长在7月和8月。随着海拔高度的增加，当前的芽和针叶的最终长度下降。当前拍摄长度也短，在迎风网站比背风网站。在所有站点，叶片衰老集中发生在8月中旬和9月中旬。针寿命，即，最古老的活针连接到一个芽的年龄，随着海拔的增加而增加。束密度，即，单位枝长上的现存针叶束数在高海拔迎风坡比低海拔背风坡多.白皮松枝的季节动态特征是在初秋同时用新针叶替换旧针叶，从而避免了生长季冠层光合生产的损失。针叶寿命和束密度的增加与气温下降和风暴露的增加有关。针叶寿命和束簇密度是矮松适应性可塑性的特征，可防止其在高寒地区逆境条件下生长潜力的降低。
Seasonal shoot dynamics of Japanese mountain stone pine (Pinus pumila Regel.) growing at six sites with different altitudes and slope aspects on the Kiso mountain range in central Japan were investigated. The shoots followed a similar growth pattern at all sites; current shoots elongated rapidly during June and July, and the current needles grew during July and August. Final lengths of the current shoots and needles decreased with increasing altitude. Current-shoot lengths were also shorter at the windward sites than at the leeward sites. At all sites, leaf senescence occurred intensively between mid-August and mid-September. Needle longevity, i.e., the age of the oldest living needle attached to a shoot, increased with increasing altitude. Fascicle density, i.e., the number of current needle fascicles on a unit shoot length, was greater at higher altitudes and windward sites than at lower altitudes and leeward sites.Seasonal dynamics of the P. pumila shoots were characterized by simultaneous replacement of old needles with new needles in the early autumn, thus avoiding any loss of canopy photosynthetic production during the growing season. Increases in needle longevity and fascicle density were associated with declining air temperature and increasing wind exposure. Needle longevity and fascicle density were characteristics of adaptive plasticity in P. pumila that prevent a reduction in growth potential in the stressful conditions of alpine regions.