Env Exp Biol (2012) 10: 81–87

Natural structures and disturbances in an old growth wet Norway spruce forest in the nature reserve Gruzdovas meži, Latvia

Abstract

To increase wood productivity, wet Norway spruce forests have been subject to drainage. In Latvia natural wet Norway spruce stands are rare, and research on these forest types is insufficient. We studied forest structures and disturbance in the nature reserve Gruzdovas meži, which appeared to include the largest (5.6 ha) old wet Norway spruce stand in Latvia. Four sampling plots were established in a Myrtilloso-polytrichosa stand. Data on tree species composition, age, diameter and height was collected. Periods of major disturbances were determined by growth release analysis. The stands had multi-age structure, characteristic of old, natural forest. The oldest Norway spruce was 273 years old. High numbers of Norway spruce seedlings indicated abundant natural regeneration. The maximal age of trees indicated the naturalness of the area. The age structure and growth release analysis indicated regeneration after the large-scale disturbances (wind, snow). The amount of dead wood was high (82 m³ ha^–1). The results showed that the investigated stand is oldest natural Norway spruce forest in Latvia.