Manning William J
Department of Plant, Soil and Insect Sciences, University of Massachusetts, Fernald Hall, 270 Stockbridge Rd., Amherst, MA 01003-9320, USA.
Environ Pollut. 2005 Oct;137(3):443-54. doi: 10.1016/j.envpol.2005.01.031.
Much has been written about the effects of ambient ozone on tree growth. Cause and effect has been established with seedlings in chambers. Results from multi-year studies with older tree seedlings, in open-top chambers, have been inconclusive, due to chamber effects. Extrapolation of results from chambers to trees in the forest is not possible. Predictive models for forest tree growth reductions caused by ozone have been developed, but not verified. Dendrochronological methods have been used to establish correlations between radial growth reductions in forest trees and ambient ozone exposure. The protective chemical ethylenediurea (EDU) has been used to protect tree seedlings from ozone injury. An experimental approach is advocated here that utilizes forest trees selected for sensitivity and non-sensitivity to ozone, dendrochronological methods, the protective chemical EDU, and monitoring data for ambient ozone, stomatal conductance, soil moisture potential, air temperature, PAR, etc. in long-term investigations to establish cause and effect relationships.
关于环境臭氧对树木生长的影响，已有大量著述。在实验室内，已确定了臭氧对幼苗生长的因果关系。然而，在开顶式气室中对大龄树苗进行的多年研究结果却尚无定论，这是由气室效应导致的。因此，无法将气室内的研究结果外推至森林中的树木。虽然已开发出预测臭氧导致森林树木生长减少的模型，但尚未得到验证。树木年代学方法已被用于建立森林树木径向生长减少与环境臭氧暴露之间的相关性。保护性化学物质乙二脲（EDU）已被用于保护树苗免受臭氧伤害。本文提倡一种实验方法，即在长期调查中，利用对臭氧敏感和不敏感的森林树木、树木年代学方法、保护性化学物质EDU以及环境臭氧、气孔导度、土壤水分势、气温、光合有效辐射等的监测数据，来建立因果关系。
