大气CO_2浓度倍增对植物某些生理特性的影响

采用开顶式培养室盆栽土培方法，研究大气CO2浓度倍增条件下几种植物的生长及生理反应，结果表明：CO2浓度倍增明显促进植物生长，提高植物地上、地下部分的生物量，但生物量增幅因物种、生长阶段和环境氛素水平的不同而异；根冠比变化一般表现为增加趋势；同时植物根系与固氮微生物及泡囊丛枝菌根的共生加强，根系结瘤量增多，平均瘤重增加，固氮活性提高，菌根侵染率增加。

INFLUENCES OF DOUBLED CO_2 IN THE ATMOSPHERE ON SOME PHYSIOLOGICAL CHARACTERISTICS OF PLANT SPECIES

Effects of doubled CO2 in the atmosphere on some physiological characteristics of several plant species have been studied in the open - top chambers. The results are shown as follows: doubled CO2 promoted remarkably plant growth and increased the biomass in both shoot and root, but individual species responded differently to doubled CO2. The amount of increase was affected by plant growing stages and nitrogen levels of the growing condition. Different species exhibited different root/shoot(R/S) ratios, and there was no clear pattern of R/S among species in response to the elevated CO2level. Moreover, doubled CO2 significantly stimulated the symbiotic combination of plant roots and nitrogen - fixing bacteria or vesicular - arbuscular mycorrhiza. Enriched CO2 induced the increase of nodules in each plant and of nodles' average weight and of total nitrogen - fixing activity. In the meanwhile, the mycorrhizal colonization in plant roots was increased consequently.