紫外线辐射对小麦和燕麦竞争性平衡的影响--小麦和燕麦生物量结构与冠层结构

在模拟１５％臭氧层减薄条件下讨论了紫外线辐射增强对大田中小麦和燕麦在单独种植与混合种植时的生物量结构和冠层结构的影响。紫外辐射使两物种的生物量减少，使节间缩短，叶片着生高度下降，但使根冠比和单株有效穗数增加。两物种在单种和混种时对紫外辐射的反应有所不同，种间竞争有时加强紫外辐射的影响，但有时则又能抵消其作用。紫外辐射使竞争性平衡向有利于小麦的方向发展，这一改变可以部分地由两物种的生物量及冠层结构对

Effect of enhanced ultraviolet radiation on Competitive balance of wheat and oat-the structure of biomass and canopy

The structure of biomass and canopy of wheat ( Triticun aestivum ) and oat (Avena sativa) in monoculture and mixture under supplementary UV radiation(approximately a 15% ozone layer depletion) were studied.The dry weight,internode length and leaf insection height were reduced,while the Root Shoot Ratio(RST) and eat numbers per plant were increased by enhanced UV radiation. The response of these two species to UV radiation were different between monocilture and mixture.Interspecific competition could alter the effects of UV radiation on wheat and oat.The competitive balance of these two species was shifted in favor of wheat by supplementary UV radiation based upon biomass production.The change of competitive balance could be interpreted partially by the different morphological responses of wheat and oat to UV radiation.The results also implied that the response of a species to UV radiation in monoculture or planted separately could not always be used to predict its response in mixtures to UV radiation.