Picea abies sapling height growth after cutting Vaccinium myrtillus in an uneven-aged forest in northern Sweden

Abstract

The study investigated the hypotheses that Norway spruce ( Picea abies (L.) Karst.) sapling growth is reduced by the occurrence of bilberry ( Vaccinium myrtillus L.) through either resource competition or allelopathy. A field experiment was established with a randomized block design and five treatments including one control in an uneven-aged Norway spruce forest. Bilberry stems were cut in a 0.56 m radius (1 m 2 ) around each treated spruce sapling, and removed or left lying. In the following year treatments were repeated on half of the spruce saplings. Sapling height increments were measured for six growing seasons after applying the treatments. Saplings reacted with a decrease in height increment compared with the control during the first and second year after applying treatments, and had height increments similar to the control the following three years. No significant differences were found between treatments removing or leaving bilberry cuttings. The results did not support the hypotheses.