oa Responses of terrestrial ecosystems under climate change manipulation: Effects of open field experimental warming and precipitation manipulation on ecophysiological characteristics of plants

It is expected that air temperature will increase and the pattern of precipitation will change. In Qatar, mean annual temperature and rainfall during winter have increased for the past 40 years. Changes in temperature and precipitation might influence ecosystem function such as productivity and nutrient cycling. Numerous climate change manipulation studies have examined the effect of climate change on ecosystem function. There are various methods for warming and precipitation manipulation; temperature can be increased by using greenhouse, open top chamber, infrared lamp and heating cable, and precipitation can be artificially manipulated by using panels to block out rain and water irrigation. However, there is a very limited number of experimental manipulation studies in arid regions compared to other ecosystems. We conducted three experimental warming and precipitation manipulation studies in Korea by using infrared lamp, transparent panel and irrigation system. Seed germination rate of Pinus densiflora and Abies holophylla increased by the warming treatment, and root collar diameter and height of 5 tree species seedlings out of 8 target tree species increased by the warming treatment. Also, the warming treatment extended the growing season by advanced leaf unfolding and delayed leaf senescence of P. densiflora and Quercus variabilis seedlings. Photosynthetic responses were species-specific to the warming treatment and net photosynthetic rate of P. densiflora seedlings decreased by the warming treatment with decreased precipitation. Based on our study, it appeared that the ecophysiological responses of seedlings to climate change manipulation varied by species. Further studies are needed to investigate the effects of multiple environmental factors including CO2 on ecophysiological characteristics of plants to climate change. In addition, long-term monitoring and modeling approaches should be simultaneously applied to understand regional climate change impact.