以天宝岩国家级自然保护区长苞铁杉纯林和长苞铁杉+阔叶树混交林的林窗为研究对象,分析林窗内光照强度、空气和土壤温、湿度等微环境特征。结果显示:不同长苞铁杉林林窗的光照强度和空气温度均表现为长苞铁杉纯林〉长苞铁杉+阔叶树混交林,中心区〉扩展区〉非林窗区,而其平均空气湿度呈相反趋势;土壤温、湿度变化在不同林窗中存在异质性;长苞铁杉纯林的微环境因子变化幅度比长苞铁杉+阔叶树混交林大,且林窗越大变化幅度越大;林窗光照强度平均日变化呈正态分布曲线,正午最高;林窗空气和土壤温度平均日变化呈单峰凸型曲线,空气和土壤湿度则呈相反趋势。研究表明:随着长苞铁杉林林窗的林分类型、面积大小、林窗内外位置和Et变化时段的不同,林窗微环境因子会发生相应变化;林窗面积越大,林窗内光照强度和空气温度越大,空气和土壤温、湿度变化越剧烈;长苞铁杉+阔叶树混交林改善林窗内小气候的作用较长苞铁杉纯林强。
In the Tianbaoyan National Nature Reserve, forest gaps of Tsuga longibracteata W. C. Cheng pure forests and T. longibracteata + broad-leaved mixed forests were selected to analyze gap micro-environment of endangered plant T. longibracteata forests. The results showed as follows. The illuminance and air temperature in different sizes of forest gaps of T. longibracteata forests were arranged in the following way : T. longibracteata pure forests 〉 T. longibracteata + broad-leaved mixed forests, center of gap 〉 expanded gap 〉 non-gap, but the average air humidity displayed the opposite trend. There was heterogeneity in changes of soil temperature and humidity in different forest gaps. The micro-environmental factors in T. longibracteata pure forests changed more significantly than those in T. longibracteata + broad-leaved mixed forests, and the greater the forest gap, the more significantly the change. The diurnal variation of average illuminance in the gaps was normal distribution curve with the highest at noon. The diurnal variation of average air and soil temperature in the gaps was single peak convex curve, but the air and soil humidity presented the opposite trend. It was concluded that the gap micro-environmental factors changed with the forest stand types, size, location and time of T. longibracteata forests gaps. The bigger the gap size, the more illuminance and higher air temperature, the greater the air and soil temperature and humidity changed. In improving micro-climate of forest gap, T. longibracteata + broad-leaved mixed forests were better than T. longibracteata pure forests.