[The effects of climate change on isoprene emission rate from leaves of Pleioblastus amarus in different regions]

Based on the RCP2.6, RCP4.5, RCP6.0 and RCP8.5 climate change scenarios produced by the global climate model NorESM1-M and plant isoprene emissions model, the effects of climate change on the isoprene emission rate from leaves of Pleioblastus amarus in Yixing City of Jiangsu Province, Longmen County of Guangdong Province, Yulong Naxi Autonomous County of Yunnan Province and Wanyuan City of Sichuan Province were simulated. The differences of isoprene emission rate from leaves of P. amarus distributed in four regions were compared under future climate change scenarios. The results showed that mean annual air temperature would increase, annual precipitation and radiation intensity would greatly fluctuate, with the coexistence of increasing and decreasing trends in the four regions. In the baseline scenario, daily mean emission rate of isoprene from leaves of P. amarus was 71-470 μg·g^-1·d^-1, and annual mean value was 25954-171231 μg·g^-1·a^-1. The daily and annual emission rates in the four regions decreased with the order of Longmen, Yixing, Wanyuan and Yulong. Compared with the baseline scenario, daily mean emission rate of isoprene from leaves of P. amarus was about 4-45 μg·g^-1·d^-1 higher in future climate change scenario, and which was about 23, 29, 4, and 14 μg·g^-1·d^-1 higher than that in baseline in Yixing, Longmen, Yulong and Wanyuan, respectively. In addition, the emission rate of isoprene from leaves of P. amarus was more than 5% higher in the future climate change scenario than that in the baseline scenario, which was higher in Wanyuan and Yixing (>13%) than and lower in Longmen and Yulong (>5%). All the four regions reached the highest rate under RCP8.5 scenario (increased by about 11%-18%). Compared with the baseline scenario, annual emission rate of isoprene in the future climate change scenario was about 1500-17000 μg·g^-1·a^-1, and which was about 8560-13208 μg·g^-1·a^-1 higher in Yixing, 10862-16131 μg·g^-1·a^-1 higher in Longmen, 1574-3028 μg·g^-1·a^-1 higher in Yulong, 5288-8532 μg·g^-1·a^-1 higher in Wanyuan. In addition, the increasing rate of annual isoprene emission rates was 6%-14%. The rates in Yixing (8%-12%) and Wanyuan (8%-14%) were higher than that in the other two regions, the rate in Yulong (6%-12% increase) was the lowest, with all four regions increasing substantially (9%-14%) under RCP8.5 scenario. The results suggested that climate change would have different effects on the rate of isoprene emissions from leaves of P. amarus distributed in diffe-rent regions.