大气中二氧化碳（CO2）浓度已由工业革命前约280umol/mol增加到目前约400umol/mol，平均温度升高了0.84℃，未来二者仍将同步持续增高。在光热条件变化背景下，近年来北方稻田最优势杂草稗草发生严重，通过掠夺光热资源和土壤养分，严重弱化了水稻长势，影响水稻的产量和品质。本项目拟采用FACE平台，将稻田稗草和水稻按不同种植比例开展CO2浓度与温度增高的模拟试验，观测稗草和水稻生理代谢与养分吸收能力的变化，获得稻田稗草对CO2浓度与温度增高响应的试验数据，进行FACE增温条件下稗草生理响应以及稗草和水稻竞争关系比较研究，阐明CO2浓度增高对稻田稗草生长发育以及稗草与水稻竞争关系影响的机理，提高气候变化对作物生长发育影响的认知。

The atmospheric CO2 concentration has reached to 400 umol/mol currently from 280 umol/mol before the Industral Revolution(1750), and the temperature also increased more than 0.84℃. accordingdly, both CO2 concentration and temperature will be increased continuely in the coming days. As one of the substrates for plant photosynthesis, CO2 concentration increasing had and will be affected profoundly plants physiology, metabolism and population competition. The barnyardgrass(C4) is the dominant weed for rice in North China. Under the impacts of climate warming and planting patterns change in recent years, the barnyardgrass is becoming more and more serious in paddy field in North China, which weaken rice growth and development, destroied rice yield and quality, by plundering light, radiation and soil fertilizer with rice. In the reseach project proposal, a four-year field experiment, in which different ratio of barnyardgrass and rice,treated with CO2 enrichment and temperature increasing, would be desiged, is planning to be conducted in Changping Agricultural Experiment Station, by using of the FACE system (CAAS FACE) in North China. The physiological factors and metabolism features, and soil fertilizer absorb characteristic of barnyardgrass and rice would be observed parallelly, a series of experimental data about response of barnyardgrass to CO2 enrichment under FACE system with tempreture increasing would be collected. The different responses between barnyardgrass and rice to CO2 enrichment and temperature increasing, and their competition relationship would be compared and analyzed. As a result, the impact mechanism of CO2 enrichment and temperature increasing on barnyardgrass under FACE system, and the competition relationship between barnyardgrass and rice would be explained and delivered. The outcomes of the research will promote understanding on the impacts of CO2 enrichment and climate warming on crop population development.