长白山云冷杉针阔混交林林隙夏季光照特征研究

Characteristics of Light Intensity in Summer in the Gaps in the Mixed Spruce-Fir Forest in Changbai Mountain

以长白山云冷杉针阔混交林3个不同大小的林隙(Gap1,456.2 m2,Gap2,290.2 m2和Gap3,83.9 m2)为研究对象,以实际小气候要素(光照、空气温度、土壤温度和湿度)观测数据为基础,对林隙光照强度特征初步分析。结果表明:光照强度在林隙中央位置、南北和东西方向的时空变化具有差异性,其中,S-N方向上的变化幅度大于E-W方向。中央位置的光照强度、湿度、空气温度、土壤温度的昼间变化均呈现了不对称的单峰型变化趋势;林隙内光照强度最大值出现的位置和时间不同,Gap1光照强度的最高值出现在中央位置附近,出现时间在11:00-13:00;Gap2出现在中央位置偏东北附近,出现时间在13:00-15:00;Gap3则出现在中央位置偏北附近,出现时间在11:00-13:00;林隙光照强度在一天当中的差异程度也不同,上午和下午差异不显著,中午以及中午前后时间段上差异显著(P<0.05)。

Three gaps of different sizes in the spruce-fired forests in Changbai Mountains were studied,based on continual observation on micro-climate factors,the characterstics of light intensity in different gaps were analyzed.The results indicated that there was time and spatial difference in the light intensity in the gap center,south-north and east-west directions.Meanwhile,the changes in the light intensity was larger in the S-N than those in the E-W.The light intensity,humility,temperature,soil temperature all exhibited single peak changing tendency in the center of the gaps;the maximum light intensity occurred at different time and in different locations in the gaps.The highest light intensity was near the center for gap1,and the appearing time was 11：00-13：00;but the highest light intensity was on the northeast sites near the center and on the north sites near the center respectively for gap2 and gap3,and their appearing time was 13：00-15：00 and 11：00-13：00 respectively.The light intensity changed in the daytime.It changed insignificantly in the morning and afternoon,but significantly around noon（P0.05）.