Nutrient Deficiency of Spruce Needles Caused by Root- and Butt Rots - A Factor in Forest Decline : Root and Butt Rots

Uppsala

International Union of Forest Research Organizations, Swedish University of Agricultural Sciences

1994

S. 181-193

7 Lit. Ang.

Bandaufführung

13462

73458

Since the late seventies and early eighties acute needle yellowing of Norway spruce (Picea abies L.) followed by forest decline had been observed in different parts of Austria. Trees with "needle yellowing" usually show specific nutrient deficiency, whereas trees of normal colour in the neighbourhood seem to be adequately supplied. This indicates, that leaching may not be the reason for acute needle yellowing. Between 1989 and 1992, 19 healthy and 19 diseased spruce trees on 3 different forest sites in Austria were felled, examined for presence of root and butt rots and nurtient contents of needles and of root and stem sapwoods compared. Trees with acute needle yellowing had significantly higher rates of root and/or butt rot, low levels of potassium, calcium and magnsesium in needles, and up to 7 times more potassium, calcium and magnesium in the sapwood of roots and lower stem parts. Mineral deficiency in spruce needles and acute yellowing as a symptom are therefore seen to be induced by physiochemical reactions like cell wall construction and compartimentilisation of wood due to fungal attack rather than leaching.