Results from linear mixed model with plant macronutrient concentration and Cu as dependent variables for the period 2004–2006. DT = distance to tree base; OR = orientation. (b) = variance estimate for intercept random effect. Toeplitz = value for the log-likelihood ratio test (χ2) testing the model with Toeplitz residual variance against the same model but with variance components residual variance (I·σ2). July is not included in the analyses to balance the data.