臭氧污染与陆地生态系统生产力

空气污染的严重性、普遍性和不断发展的趋势及其对陆地生态系统生产力造成的重大影响已引起科学工作者的高度重视,成为一个急需解决的重要课题。对流层臭氧(O₃)在空气污染现状与未来发展趋势中占据重要角色,该文重点探讨了O₃对陆地生态系统生产力的光合、分配、生长和产量形成等主要过程的影响及其对整个生态系统的长期效应,并评述了相关研究方法进展。主要结论包括:O₃在生产力形成过程中的每个环节中都有着不同程度的负面影响,通过影响光合作用和气孔导度,减少根冠比改变碳分配量,而最终导致粮食生产和森林生物量损失率高达30%;气候变化、CO₂和O₃协同作用对植物影响较为复杂,有促进也有抑制;生态系统模拟已成为研究O₃污染影响陆地生态系统生产力的主要方法之一,在区域评估和未来气候预测方面都具有重要作用。

EFFECTS OF OZONE POLLUTION ON TERRESTRIAL ECOSYSTEM PRODUCTIVITY

Air pollution is a key factor that threatens earth’s ecosystems and sustainability. Tropospheric ozonecontinues to be of major concern in the field of air pollution effects on terrestrial ecosystem productivity. In this paper, we have reviewed recent progresses in the studies of ozone effects on terrestrial production processes (including plant photosynthesis, carbon allocation, plant growth and crop yield), nutrient cycling, and species composition. Increased evidence shows that ozone can reduce the capability of photosynthesis by influencing leaf area and stomatal conductance, and alters the pattern of carbon allocation between shoot and root. Previous studies have also shown that elevated ozone could result in a maximum loss of 30% crop yield or forest production. However, little is known about how elevated ozone affects decomposition, nutrient cycling, species composition and trophic dynamics. There is an urgent need to investigate the synergetic effects of ozone pollution and climate change on terrestrial ecosystems. To address such a complex and large-scale environmental problem, spatially-explicit process-based ecosystem models have been used extensively in recent years. To advance our understanding of how air pollution and climate change influence terrestrial ecosystem productivity, further studies are needed to address multifactor experiments in the field and enhance the interaction between field studies and modeling.