Abstract: Canopy temperature (T_c) is one of the key ecophysiological indices to measure plant moisture and heat. In this study, we measured T_c and other meteorological parameters (air temperature, precipitation, relative humidity, vapor pressure deficit, net radiation, and wind speed) during 2014 to 2016 in a rubber plantation, Xishuangbanna, Southwest China. We aimed to reveal the variations of T_cand its relationship with meteorological factors. The results showed that the diurnal variation of T_c exhibited a single peak in dry season and bimodal trend in rainy season. The annual variation of T_c showed a unimodal trend. The T_c was higher in rainy season than that in dry season. Furthermore, the mean T_c was always higher than air temperature throughout the year. The correlation between T_c and meteorological factors was as follows: air temperature>vapor pressure deficit>net radiation>wind speed>relative humidity>precipitation, with air temperature having the strongest effects on T_c (r=0.92, P<0.01, n=1096). Partial correlation analysis showed that air temperature, net radiation and vapor pressure deficit had significant effects on T_c in both rainy and dry seasons. The main factors influencing T_c were air temperature and net radiation in dry season, whereas air temperature and vapor pressure deficit were main factors for rainy season. This study manifested the variation characteristics of T_c and its relationship with meteorological factors in Xishuangbanna, which provided a basis for understanding the affecting factors of T_c.

Key words: rubber plantation, canopy temperature, canopy temperature difference, meteorological factor, infrared temperature sensor.