作者: E. Dambrine , A. Granier , G. Lévy
DOI: 10.1007/978-3-642-79535-0_13
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摘要: Two main symptoms are typical of silver fir (Abies alba Mill., hereafter shortened to “fir”) and Norway spruce (Picea abies (L.) Karst., “spruce”) decline in Europe: (a) crown thinning; (b) yellowing old needles, the latter being mostly related Mg deficiency on acid soils (Roberts et al. 1989; Bonneau 1989). Crown thinning, when not associated with strong mineral deficiencies, may be caused by various abiotic biotic factors. In Vosges, it has been mainly water stresses, often increased high stand density (Levy Becker 1987). fact, both needle loss (when derived from acute deficiencies) reduced growth appear long lasting effects sequence dry years which occurred during 1960s 1970s.