Wang Bin, Shugart Herman H, Shuman Jacquelyn K, Lerdau Manuel T
Department of Environmental Sciences, University of Virginia, PO Box 400123, Clark Hall, 291 McCormick Road, Charlottesville, VA 22904-4123, USA.
Sci Rep. 2016 Feb 22;6:22133. doi: 10.1038/srep22133.
Tropospheric ozone is a serious air-pollutant, with large impacts on plant function. This study demonstrates that tropospheric ozone, although it damages plant metabolism, does not necessarily reduce ecosystem processes such as productivity or carbon sequestration because of diversity change and compensatory processes at the community scale ameliorate negative impacts at the individual level. This study assesses the impact of ozone on forest composition and ecosystem dynamics with an individual-based gap model that includes basic physiology as well as species-specific metabolic properties. Elevated tropospheric ozone leads to no reduction of forest productivity and carbon stock and to increased isoprene emissions, which result from enhanced dominance by isoprene-emitting species (which tolerate ozone stress better than non-emitters). This study suggests that tropospheric ozone may not diminish forest carbon sequestration capacity. This study also suggests that, because of the often positive relationship between isoprene emission and ozone formation, there is a positive feedback loop between forest communities and ozone, which further aggravates ozone pollution.
对流层臭氧是一种严重的空气污染物，对植物功能有很大影响。这项研究表明，对流层臭氧虽然会损害植物新陈代谢，但不一定会降低生态系统过程，如生产力或碳固存，因为群落尺度上的多样性变化和补偿过程会减轻个体层面的负面影响。本研究使用基于个体的间隙模型评估臭氧对森林组成和生态系统动态的影响，该模型包括基本生理学以及物种特异性代谢特性。对流层臭氧浓度升高不会导致森林生产力和碳储量下降，反而会导致异戊二烯排放增加，这是由于排放异戊二烯的物种（比不排放者更能耐受臭氧胁迫）优势增强所致。这项研究表明，对流层臭氧可能不会削弱森林的碳固存能力。这项研究还表明，由于异戊二烯排放与臭氧形成之间通常存在正相关关系，森林群落与臭氧之间存在正反馈回路，这进一步加剧了臭氧污染。
