摘要
探讨城市河岸带夏季土壤表层5 cm温度(以下简称土温)的多时间尺度变化,并据此分析影响不同时间尺度域内土温发生波动的因素.小波分析结果表明,土温可在多个时间尺度域上变化,具有5个时间特征尺度.土温在日、旬和两旬尺度上的波动主要受总太阳辐射量变化的影响;在月和季节尺度上的波动主要受下垫面植被配置的影响.其中,在月和季节尺度上,地上植物生长状况对土温的影响较大,且不同植被类型(针叶大乔木、阔叶小乔木、阔叶大乔木和草灌植物)的草灌层覆盖度和高度及乔木层叶生物量对土温变化的影响程度不尽相同.植被类型和冠层结构对土温变化也有一定影响:冠层株型为圆锥形的针叶乔木下的土温显著低于株型为球形的阔叶乔木下的土温.另外,相比阔叶乔木,针叶乔木的降温效应更为明显:当针叶乔木下的草灌层覆盖度达到30%时,表现出明显的降温效应;而对于阔叶乔木,覆盖度需达到60%.
This study investigated the variation in the soil temperature in the top 5 cm of the soil on multiple temporal scales and its driving factors for an urban riparian zone in summer. Wavelet analysis showed that the top soil temperature varied within multiple domains of temporal scale. The variation in the top soil temperature on small temporal scales （daily, ten-day, and twenty-day） was mainly due to the variation in total solar radiation, while on large temporal scales （monthly and seasonal） it was mainly influenced by vegetation composition and configuration. Firstly, plant growth had significant effects on top soil temperature. Vegetation coverage and height and tree leaf biomass played different roles in variation in the top soil temperature when vegetation types were different. Secondly, the top soil temperature was also influenced by vegetation type and canopy structure as vegetation coverages were similar. In addition, compared with the broad-leaved trees, the coniferous trees had more noticeable cooling effect.
出处
《中国科学院大学学报（中英文）》
CSCD
北大核心
2016年第6期758-768,共11页
Journal of University of Chinese Academy of Sciences
基金
北京市自然科学基金(8132045)
中国科学院知识创新工程重要方向项目(Y225016EA2)资助
关键词
时间尺度域
小波分析
地上植物生长状况
植被类型
冠层结构
domain of temporal scale
wavelet analysis
aboveground plant growth
vegetation type
canopy structure
