芦芽山林线组成树种白杄径向生长特征及其与环境因子的关系

在山西芦芽山林线附近,应用树干径向变化记录仪(Dendrometer)测量了6株白杄树干的径向生长过程,同步监测环境因子.观测期分为两个阶段,分别是7月15日～8月7日(夏季期),9月5日～10月9日(秋季期).结果表明:(1) 白杄树干径向变化在晴好天气呈现出有规律地波动式上升,在阴雨天气下则表现为持续上升,降雨结束后迅速下降;(2) 树干径向生长生长曲线在两个阶段都呈二次曲线形式,在夏季期内树干径向生长为正,在秋季期初始阶段为负在9月中旬后逐渐变为0.(3)在两个观测期内的非降雨期内,树干径向变化与空气温度负相关,与空气相对湿度、土壤含水量、土壤水势正相关与土壤温度相关关系在两个时期内不同;在两个观测期内的降雨时段内,树干径向变化与环境因子的相关关系均不同.(4) 距离分析结果表明,在秋季期内,温暖湿润的环境适宜白杄的生长,在夏季期内,湿润环境有利于白杄的生长.

Stem radius growth features of Picea meyeri and its relationship with environmental factors at the treeline of Luya Mountain

The Stem radius variation (SRV) was measured by dendrometer from six sample trees of Picea meyeri at the tree-line of Luya Mountain, North China, combined with synchronized instrumental observation and measurement of habitat temperature, moisture, etc., from July 15th to the August 7th (summer phase) and from September 5th to October 9th (autumn phase) in 2007. The preliminary analytic results were as follows: (1) the diameter of stems varied on sunny days with a daily fluctuation but steadily widened, while on rainy days it continuously increased during the rain but shrinked rapidly after the rain. (2) The Stem radial increment(SRI) pattern in both phase, was fitted with a conic curve pattern, The SRI was shown a positive value in the summer phase, whereas in the autumn phase, it was turned out to be a negative figure first in early September but then kept as a zero constantly from the middle September on. (3) In no rain stage of both of these phase, the stem radius variation (SRV) was negatively correlated with air temperature and positively correlated with relative humidity (RH), soil moisture and soil water potential. Correlations between SRI and soil temperature were different. Daily stem fluctuation rhythm broken by precipitation correlations of soil temperature and other factors were different in rainy phase of both phases. (4) Through distance analysis, we found that a relative warmer and moister environment was suitable in autumn phase, and high RH and soil moisture was suitable for the growth of Picea meyeri in summer phase.