中文摘要：

以侧柏（Platycladus orientalis）纯林为对照,研究了侧柏-山毛桃（Prunus davidiana）群落混交林初夏和秋季山毛桃荫蔽侧柏的小气候效应.结果表明,混交林对林内空气温度的午间降温效应不明显,而秋季降温效应随着郁闭度增加而增大,使侧柏小气候环境提高了湿润度,相当于生长季增加了26.5 mm的降水;初夏和秋季林内10 cm处地温日间呈持续增加趋势,最快速升温的时间点无论是初夏还是秋季,有山毛桃荫蔽的均提前0.5～1 h.最大升温速率均小于无荫蔽的处理;初夏林内空气相对湿度保持与气温位相相反的大陆性气候特征,而秋季这种日变化特征消失,林内空气相对湿度趋于稳定;午间适度荫蔽有利于提高侧柏幼苗净光合.研究得出结论：山毛桃-侧柏混交林能降低林内空气的蒸发力,减缓林内土壤升温幅度和速率,增加林内空气湿度,并平缓林内空气湿度的波动.

英文摘要：

In early summer and autumn we studied the microclimate effect of mixed forest of P. orien- talis and P. davidiana P. orientalis monoplantation as a contrast. The results showed： In early sum- mer, the effect of air temperature decreasing around noon period was not clear, whereas in autumn the effect of air temperature decreasing around noon period increased along with density increase. The shading effect of P. davidiana increased moist degree and virtually increased precipitation by 26.5ram during the growing season. Soil temperatures at 10 cm depth continually increased in the daytime. The times of rapid soil temperature increasing within P. orientalis and P. davidiana mixed forest were 0.5 ~ 1.0 h earlier than that of the P. orientalis monoplantation regardless of in early summer or autumn. And the maximum soil temperature increasing rate was lower than the P. orientalis monoplantation. In early summer, the phase of air humidity was reverse to that of air temperature, which was a typical characteristic of continental climate. In autumn, the typical characteristic of continental climate disap- peared. The air humidity changed little. The averages of air humidity of different treatments were close to each other in early summer, whereas in autumn it increased along with forest density increasing. At noon period, when air temperature was high, shading helped photosynthesis. The paper concluded ： P. orientalis and P. davidiana mixed forest reduced air evaporation capacity, decreased soil temperature rising rate and range, increased air humidity and gentled its fluctuation it was advantageous to reduce exceeding water consumption.