Stem Form and Taper Changes After Thinning and Nitrogen Fertilization in Picea abies and Pinus sylvestris Stands

摘要: Stem form and taper changes after thinning combined with N fertilization were studied in 23 Norway spruce [Picea abies (L.) Karst.] 46 Scots pine (Pinus sylvestris L.) stands Sweden observed for 5-28 yrs. Average was calculated the stem section 1.3-6.0 m above ground level as ratio between diameter at breast height total tree periods of 5-10 At start experiment, before first thinning, dominant 12-15 m. Once 65% basal area had been removed a single from below, remaining trees showed strong increase compared unthinned stands. Stems treated heavily recurrent thinnings below also increased taper, although increases not always statistically significant. Trees thinned, N-fertilized middle northern developed more pronounced stems equally unfertilized