sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

2. MATERIAL & METHODS
SDÜ ORMAN FAKÜLTESİ DERGİSİ
The experiment was established in a mature Norway spruce stand in Upper
Austria. Two fertilizer treatments and an unfertilized control variant were applied
on a total of 144 dominant or co-dominant trees in a randomized block design
(Fig. 2) in April 2001. Half of the trees exhibited symptoms of Sirococcus shoot
blight (“diseased”), whereas the other trees were “healthy”. The average basal area
increment of the two groups diverged after the year 1980, therefore analysis of
covariance was applied for testing the effects of fertilization and Sirococcus
symptoms on volume increment, using the average of the current annual increment
in the period 1977 to 1980 as the covariate.
Figure 2. Position of the sample trees within the experimental stand. The tree position is
marked with different symbols for the variants. Trees from the slope position “upper slope”
are found northern to the dotted line. (Figure reprinted from Huber et al. 2009 with
permission from Elsevier.)
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