哀牢山亚热带常绿阔叶林内外地温分布特征

地温是森林气候重要的环境因素之一,与植物生长密切相关,对地温的深入研究有助于揭示森林生态系统功能和评估森林环境效益。本文利用哀牢山亚热带常绿阔叶林林内和林外旷地(气象站)地温数据,分析发现:哀牢山亚热带常绿阔叶林林内外的地温均呈单峰型日变化,与林外相比,林内地温具有明显日变化的深度较浅(仅在20cm深度以上);林内平均地温具有显著日变化的深度在春季和秋季(20cm)要大于夏季和冬季(15cm);与林外相比,林内各层地温均小于同层的林外地温,并且林内地温的日变幅和年变幅也小于同深度的林外地温。总体来看,林外地温的年变幅和日变幅大于林内。

Distribution characteristics of soil temperature within and outside a subtropical evergreen broadleaved forest in Ailao Mountains, Yunnan Province of Southwest China

Soil temperature is an important environmental factor of forest climate,which closely relates to plant growth.To deeply understand the variations of soil temperature in forest is beneficial to reveal the functions of forest ecosystem and to assess the environmental benefit of forest.Our analysis on the observation data of soil temperature within a subtropical evergreen broadleaved forest and in an open area nearby in the Ailao Mountains showed that the diurnal variations of soil temperature within and outside the forest presented a single-peak curve.Compared with that in nearby open area,the diurnal variation of soil temperature in the forest was presented in shallower depths(less than 20 cm).The depth of the diurnal variation of soil temperature in the forest was deeper in spring and autumn(20 cm) than in summer and winter(15 cm).The soil temperature in the forest was lower than that in the open area at each depth,and the diurnal and annual variations of soil temperature in the forest were smaller than those in the open area.Overall,both the diurnal and the annual variation ranges of soil temperature were larger outside the forest than within the forest.