Spatial and temporal variability of foliar mineral concentration in beech (Fagus sylvatica) stands in northeastern France

摘要: Foliar mineral concentration may provide a basis for monitoring the consequences of long-term environmental changes, such as eutrophication and acidification soils, or increase in atmospheric CO(2) concentration. However, analytical drifts inter-tree year-to-year variations confound effects on changes foliar We have characterized relative these potentially confounding factors carbon, nitrogen, phosphorus, calcium, potassium, magnesium manganese concentrations 118 pure beech (Fagus sylvatica L.) stands, sampled 1969-71 1996-97. Interannual fluctuations elements were quantified subset six stands monitored 5 years. Intercalibration between methods used at each sampling period nitrogen phosphorus analyses showed significant, but low, differences (0.8 3.3% N P, respectively). Based variability, could be arranged four groups: C (constant), P (low variability), K Ca (medium Mn Mg (high variability). Inter-tree coefficients variation 2, 6, 8, 15, 18, 22 27%, respectively. Year-to-year increased order N, Mg, K, Ca, 4, 7, 9, 11, 15 29%, Between two periods, 12%, whereas decreases observed (-23%), (-38%) (-16%). Ratios N/P, N/K N/Mg by 42, 19 77%, These larger than interannual Mg/Ca. Decreasing cations particularly marked trees growing acidic positive trend did not depend soil type. Both increasing forest soils contribute to decreasing cation foliage. The with time suggests deposition effect. Whatever causes large shift element ratios indicates an accelerating imbalance status.