Darbah Joseph N T, Kubiske Mark E, Nelson Neil, Oksanen Elina, Vapaavuori Elina, Karnosky David F
Michigan Technological University, School of Forest Resources and Environmental Sciences, Houghton, MI 49931, USA.
Environ Pollut. 2008 Oct;155(3):446-52. doi: 10.1016/j.envpol.2008.01.033. Epub 2008 Mar 20.
We studied the effects of long-term exposure (nine years) of birch (Betula papyrifera) trees to elevated CO(2) and/or O(3) on reproduction and seedling development at the Aspen FACE (Free-Air Carbon Dioxide Enrichment) site in Rhinelander, WI. We found that elevated CO(2) increased both the number of trees that flowered and the quantity of flowers (260% increase in male flower production), increased seed weight, germination rate, and seedling vigor. Elevated O(3) also increased flowering but decreased seed weight and germination rate. In the combination treatment (elevated CO(2)+O(3)) seed weight is decreased (20% reduction) while germination rate was unaffected. The evidence from this study indicates that elevated CO(2) may have a largely positive impact on forest tree reproduction and regeneration while elevated O(3) will likely have a negative impact.
我们在威斯康星州莱茵兰德的白杨林自由空气二氧化碳浓度增高（Aspen FACE）试验点，研究了桦树（纸皮桦）长期（九年）暴露于高浓度二氧化碳和/或臭氧环境下对其繁殖及幼苗发育的影响。我们发现，高浓度二氧化碳增加了开花树木的数量和花朵数量（雄花产量增加260%），提高了种子重量、发芽率和幼苗活力。高浓度臭氧也增加了开花，但降低了种子重量和发芽率。在联合处理（高浓度二氧化碳 + 臭氧）中，种子重量下降（降低20%），而发芽率未受影响。这项研究的证据表明，高浓度二氧化碳可能对林木繁殖和更新产生很大的积极影响，而高浓度臭氧可能产生负面影响。
