The impact of UV-B radiation and ozone on terrestrial vegetation

摘要: Although terrestrial vegetation has been exposed to UV-B radiation and ozone over the course of evolutionary history, it is essential view effects on changing levels these factors in context other features climate change, such as increasing CO(2) changes temperature precipitation patterns. Much our understanding impacts increased come from studies each individual factor. While information may be relevant a wider roles that play experience shown interactions environmental stresses are rarely predictable. A further limitation applicability results methodologies used for exposing plants either comes growth chamber, greenhouse or field using experimental protocols made little no provision stochastic nature at earth's surface, hence excluded repair mechanisms. As result, knowledge dose-response relationships under true conditions both limited fragmentary, given wide range sensitivities among species cultivars. Adverse factor qualitatively well established, but quantitative far clear. In cases, sensitivity varies with stage plant development. At population community levels, differential responses result competitiveness structure. mechanistic level, generally inhibits photosynthetic gas exchange controlled conditions, although also inhibitory some others appear indifferent, particularly field. Both affect metabolism; common response secondary metabolism leading accumulation phenolic compounds that, case UV-B, offer leaf cell protection radiation. Virtually available about simultaneous sequential exposures. Since surface exposures have spatial temporal components, important evaluate different scenarios occur, bearing mind elevated daytime will attenuate reaching extent. The experimentation needed acquire unequivocal data situations must therefore carried out technologies focus quantification themselves their factors.