Foliation of spruce in the Giant Mts. and its coherence with growth and climate over the last 100 years

Five spruces (Picea abies [L.] Karst.) in the Giant Mts., Czech Republic we re investigated to reconstruct variations in their foliation over the last 100 years and to establish possible coherences with growth and climate. Fol iation was assessed by means of the needle traces in the main trunk. The an nual average needle production of 355 needles per shoot correlated with the annual shoot length and was affected by the temperature prevailing in Marc h and October of the previous year. A determination of needle production by the length of the vegetation period is discussed. The needle retention of the trees was 6.5 needle sets on average but there were considerable long-t erm variations, and maximum needle age even reached 9.8 years. Needle shed was between 0.1 and 2.3 needle sets per year and no connection was revealed between needle shed and radial increment or shoot growth. Needle retention and annual needle shed were independent of climate.