不同土壤水分条件下CO2浓度对禾谷缢管蚜种群的影响

利用开顶式熏气室研究了不同土壤水分条件下不同CO₂浓度对禾谷缢管蚜种群的影响,以期对未来大气CO₂浓度升高条件下不同降雨地区的小麦蚜虫关系发展趋势做出初步预测.结果表明,随CO₂浓度升高,禾谷缢管蚜种群持续增长,但以CO₂浓度从350μl·L^-1上升到550μl·L^-1时增长最快;禾谷缢管蚜种群大小与土壤水分密切相关,各CO₂浓度下均以60%土壤水分的最大;当CO₂浓度从350μl·L^-1上升到550μl·L^-1时,60%土壤水分下的种群增长最快;当CO₂浓度从550μl·L^-1上升到700μl·L^-1时,60%和40%土壤水分下的种群增长相近,且高于80%土壤水分下的增长.据此可以认为,随大气CO₂浓度升高,禾谷缢管蚜种群会持续增长,从目前至下世纪中叶的时间内可能是蚜虫种群增长最快的阶段,特别在干旱、半干旱地区禾谷缢管蚜种群增长幅度较大、小麦受害较重.

Effect of elevated atmospheric CO2 concentration on Rhopalsiphum padi population under different soil water levels

With the aim of forecasting the wheat-aphid relationships under different precipitation in the future atmospheric CO₂ environment,the effects of different atmospheric CO₂ concentration on Rhopalsiphum padi population under different soil water levels in Open-Top chambers were studied.The results showed that Rhopalsiphum padi population grew constantly with the continuous rising of atmospheric CO₂ and it grew more quickly when CO₂ concentration increased from 350μl·L^-1 to 550μl·L^-1 .In each CO₂ concentration treatment,R.padi population were distinct under different soil water level,and they were the highest under 60% of field water capacity treatment.When CO₂ concentration increased from 350μl·L^-1 to 550μl·L^-1 ,the increase of R.padi population under 60% of field water capacity treatment was higher than that under 40% and 80% treatment.When CO₂ concentration increased from 550μl·L^-1 to 700μl·L^-1 ,the increases of R.padi population under 60% and 40% soil water treatments were the same and both higher than that under 80% treatment.These results suggested that R.padi population would grow more quickly from the beginning to the middle of the 21st century and bring more damages to the wheat in arid and semiarid area.