Ferretti Marco, Calderisi Marco, Bussotti Filippo
Dipartimento di Biologia Vegetale, Università di Firenze, Piazzale Cascine 28, I-50144 Firenze, Italy.
Environ Pollut. 2007 Feb;145(3):644-51. doi: 10.1016/j.envpol.2006.02.028. Epub 2006 Jun 13.
The relationships between crown defoliation of beech, visible foliar symptoms on native vegetation and ozone exposure were investigated on permanent monitoring sites in South-Western Europe in the years 2000-2002. Relationships between defoliation of beech and O3 (seasonal mean, 2-week maximum, AOT40) were investigated by means of multiple regression models (11 plots, 1-3 years of data each) and a model based on temporal autocorrelation of defoliation data (14 plots, 1-3 years of data each). Different multiple regression techniques were used. The four models generated (R2=0.71-0.85, explained variance in cross-validation 61-78%) identified several significant predictors of defoliation, with AOT40 (p=0.008) and foliar content of phosphorous (p=0.0002-0.0004) being common to all models. The autocorrelation model (R2=0.55; p<0.0001) was used to calculate expected defoliation on the basis of the previous year's defoliation, and model predictions were used as an estimate of expected defoliation under constant site and environmental condition. Residuals (predicted-measured) plotted against current AOT40 shows that a possible effect of ozone occurs only at very high AOT40 (>35,000 ppbh). O3-like visible foliar symptoms were recorded on 65 species at 47% of the common monitoring sites in 2001 and 38% in 2002. No relationship was found between O3 exposure, frequency of symptomatic sites and frequency of species with symptoms (R2=0.11; p>0.05). A number of questions related to the ecological and methodological basis of the survey were identified. Inherent sampling and non-sampling errors and multicollinearity of the data suggest great caution when examining results obtained from mensurational, correlative studies.
2000 - 2002年期间，在欧洲西南部的永久性监测点，对山毛榉树冠落叶、本地植被上可见的叶片症状与臭氧暴露之间的关系进行了调查。通过多元回归模型（11个样地，每个样地有1 - 3年的数据）和基于落叶数据时间自相关的模型（14个样地，每个样地有1 - 3年的数据），研究了山毛榉落叶与臭氧（季节均值、两周最大值、AOT40）之间的关系。使用了不同的多元回归技术。生成的四个模型（R2 = 0.71 - 0.85，交叉验证中的解释方差为61 - 78%）确定了落叶的几个显著预测因子，其中AOT40（p = 0.008）和叶片磷含量（p = 0.0002 - 0.0004）在所有模型中都很常见。自相关模型（R2 = 0.55；p < 0.0001）用于根据上一年的落叶情况计算预期落叶量，模型预测值被用作在固定场地和环境条件下预期落叶量的估计值。将残差（预测值 - 测量值）与当前的AOT40作图显示，只有在非常高的AOT40（>35,000 ppbh）时，臭氧才可能产生影响。2001年，在47%的常规监测点的65个物种上记录到了类似臭氧的可见叶片症状，2002年这一比例为38%。未发现臭氧暴露、有症状样地的频率和有症状物种的频率之间存在关系（R2 = 0.11；p > 0.05）。确定了一些与调查的生态和方法学基础相关的问题。固有的抽样和非抽样误差以及数据的多重共线性表明，在审查从测量性、相关性研究中获得的结果时要非常谨慎。
