Energy Budget and Transpiration Characteristics of Rice Grown under Elevated CO2 and High Temperature Conditions as Determined by Remotely Sensed Canopy Temperatures

Japanese Journal of Crop Science

Hiroaki OHNISHI¹  Hang-Yong KIM¹  Hiroshi NAKAGAWA¹  Masao OHNISHI¹  Koki HOMMA¹  Takeshi HORIE¹ 

关键词: Canopy resistance;    イネ;    Canopy surface temperature;    温度傾斜型CO2濃度制御チャンバー(TGC);    CO2 concentration;    気温;    Evapotranspiration rate;    群落拡散抵抗;    Remote sensing;    群落表面温度;    Rice;    CO2濃度;    Temperature;    蒸発散速度;    Temperature gradient chamber (TGC);    リモートセンシング;   

DOI  :  10.1626/jcs.68.137

学科分类：农业科学（综合）

来源: Nihon Sakumotsu Gakkai / Crop Science Society of Japan

【 摘 要 】

The effects of elevated CO2 concentration and high temperatures on transpiration and gaseous diffusive resistances of rice canopy were investigated. Akihikari and IR36 cultivars were grown under two CO2 concentrations ( [CO2], 365 and 700 μL L-1) × three temperatures (29.8, 30.4 and 32.5°C on average over the experimental period), created by two Temperature Gradient Chambers. From 2 August (panicle initiation) to 22 August (booting), measurements were made of dry and wet bulb temperatures, canopy surface temperatures (Tc) and net radiation along with evapotranspiration (E) measurements by microlysimeters. Aerodynamic resistance (ra), obtained from the measured E and microclimate data, showed a fairly constant value (11.7 s m-1). Then, ra, Tc and microclimates data were substituted into energy budget equations to obtain E and canopy resistance (rc). In all plots, calculated E was in good agreement with measurement by lysimeters, and rc reached minimum values (rc, min) at solar radiation above 500 W m-2. Elevated [CO2] at the lowest temperature plot increased rc, min by 40-49% and Tc by 1.4-1.6°C and it reduced E by 14-16% of those under ambient CO2 conditions. With the rising growth temperature, these effects of elevated [CO2] drastically decreased. The observed rc, min responses to temperature and [CO2] seemed to have reflected a long-term acclimation of rice to these environments. These results indicate that anticipated global warming significantly reduces the advantageous effects of elevated [CO2] on plant water use.

【 授权许可】

Unknown