Spatial variability of micro-climatic conditions within a mid-latitude deciduous forest

Climate Research

J. T. Schoof¹  C. S. B. Grimmond¹  S. M. Robeson¹ 

关键词: Micro-climate;    Below-canopy;    Mid-latitude deciduous forest;   

DOI  :  10.3354/cr015137

来源: Inter-Research Science Publishing

【 摘 要 】

ABSTRACT: Micro-climatic differences within forests exert important controls, notably on understory composition, wildlife habitat, and many biogeochemical processes. This study documents the spatial variability and temporal evolution of micro-climaticconditions (air temperature, relative humidity, solar radiation and wind speed) within a mid-latitude deciduous forest, over 3 growing seasons (1995 to 1997). For all sites, in all years, conditions change markedly at the start of the growing season (Days120 to 145), simultaneous with onset of leaf-out and the development of full canopy cover. Below the fully developed canopy, radiation and wind speed are significantly reduced, both in magnitude and duration, while relative humidity increases. Within theforested ravines, spatial differences in daily maximum air temperature range from 0.5 to 4.1°C (average of 2°C) and in minimum air temperatures from 0 to 4.5°C (average of 1°C). Within the forest, solar radiation varies by 100 W m^-2 (whenmaximum values are <200 W m^-2), minimum relative humidity varies by 10 to 15%, and wind speed by 0.5 m s^-1. Local weather conditions have a strong influence on the spatial and temporal variability of all the micro-climaticvariables considered. In general, differences within the forest are greater on clear, sunny days. Once the canopy closes, the effects of topography and associated aspect/geometry dominate over micro-scale differences due to canopy structure. Lessradiation, lower air temperatures, higher relative humidity, and higher wind speeds all are documented at the bottom of the ravines. The differences in micro-climatic conditions measured within the forest are of the same order as those measured inprevious studies contrasting open and forest sites. Such spatial variability should be considered in studies of ecological and biogeochemical processes in secondary growth deciduous forests.

【 授权许可】

Unknown