Aims the relative plant type sensitivity and selected community interac-tions under increased UV-B radiation where examined.Specifically,we investigated:(i)if there are differences among growth forms in regard to thei...Aims the relative plant type sensitivity and selected community interac-tions under increased UV-B radiation where examined.Specifically,we investigated:(i)if there are differences among growth forms in regard to their sensitivity to UV-B radiation,(ii)if increased UV-B radiation influences the plant competitive balance in plant com-munities and(iii)the response mechanisms of the UV-B radiation-sensitive species that might increase their fitness.Methods to answer our research questions,we used a mechanistic model that,for the first time,integrated the effects of increased UV-B radia-tion from molecular level processes,whole plant growth and devel-opment,and community interactions.Important Findings In the model simulations,species types exhibited different levels of sensitivity to increased UV-B radiation.Summer C3 and C4 annuals showed similar growth inhibition rates,while biennials and winter C3 annuals were the most sensitive.Perennials exhibited inhibitions in growth only if increased UV-B radiation results in increases in metabolic rates.In communities,species sensitive to UV-B radiation may have a competitive disadvantage compared to resistant plant species.But,sensitive species may have a wide array of responses that can increase their fitness and reproductive success in the com-munity,such as,increased secondary metabolites production,changes in timing of emergence and reproduction,and changes in seed size.While individual plants may exhibit significant inhibi-tions in growth and development,in communities,these inhibitions can be mitigated by small morphological and physiological adap-tations.Infrequent or occasional increased UV-B radiation events should not have any lasting effect on the structure of the commu-nity,unless other environmental factors are perturbing the dynamic equilibrium.展开更多
文摘Aims the relative plant type sensitivity and selected community interac-tions under increased UV-B radiation where examined.Specifically,we investigated:(i)if there are differences among growth forms in regard to their sensitivity to UV-B radiation,(ii)if increased UV-B radiation influences the plant competitive balance in plant com-munities and(iii)the response mechanisms of the UV-B radiation-sensitive species that might increase their fitness.Methods to answer our research questions,we used a mechanistic model that,for the first time,integrated the effects of increased UV-B radia-tion from molecular level processes,whole plant growth and devel-opment,and community interactions.Important Findings In the model simulations,species types exhibited different levels of sensitivity to increased UV-B radiation.Summer C3 and C4 annuals showed similar growth inhibition rates,while biennials and winter C3 annuals were the most sensitive.Perennials exhibited inhibitions in growth only if increased UV-B radiation results in increases in metabolic rates.In communities,species sensitive to UV-B radiation may have a competitive disadvantage compared to resistant plant species.But,sensitive species may have a wide array of responses that can increase their fitness and reproductive success in the com-munity,such as,increased secondary metabolites production,changes in timing of emergence and reproduction,and changes in seed size.While individual plants may exhibit significant inhibi-tions in growth and development,in communities,these inhibitions can be mitigated by small morphological and physiological adap-tations.Infrequent or occasional increased UV-B radiation events should not have any lasting effect on the structure of the commu-nity,unless other environmental factors are perturbing the dynamic equilibrium.
