A comparative research on microclimate characteristics between ancient tea plantation and conventional tea plantation in Yunnan Province

Microclimatic measurements were conducted in the conventional tea plantation and ancient tea plantation at the germination moment of tea plants in Yunnan Province in Jan. 2003. Through the comparative research, the findings are as follows: Light intensity above the canopy of ancient tea plantation was far less than that above the canopy of conventional tea plantation and in the clearing. In the ancient tea plantation, thermal effect around the crown was negative and the quantity of heat flaw away from environment to the crown in the daytime, which depressed the air temperature around the tea; thermal effect presented positive around the crown and the quantity of heat was transferred from the crown to the environment at night, which had an effect on keeping air temperature around the tea. As there was no shield in conventional tea plantation, the air temperature around the crown was higher than that in clearing in daytime and lower than that in clearing at night. Water vapor pressure in conventional tea plantation was higher than that in ancient tea plantation in the daytime and lower than that in ancient tea plantation at night; moreover, they were on the contrary to the results of relative humidity. So, in the ancient tea plantation, light intensity was lower; air temperature of ancient tea plantation was higher in the daytime and lower at night; the diurnal range of temperature wasn't remarkable; the relative humidity was moderate. All the characteristics as mentioned above played a great role in tea growing and matter forming and accumulating within tea plant, which led to the improvement of tea quality and to some extent might be reasons that tea in ancient tea plantation kept good quality in the long time.