Potential of mixed Picea abies (L.) Karst. and Pinus sylvestris L. forests in lowland areas of Central Bohemia

Abstract

Mixed forests play a key role in terms of stability, production potential, and adaptation to climate change. In addition, the studied Norway spruce [Picea abies (L.) Karst.] and Scots pine (Pinus sylvestris L.) belong to the most economically important tree species in Europe. The objectives were to determine the effect of the species composition of these two tree genera on the production, structure, diversity, and growth of mixed stands at lower elevations in the Czech Republic. Based on dendroecological samples, research was also carried out on the influence of climatic factors and climate change on the radial growth of these trees of interest. Mixed forests showed higher timber production by 29.8% compared to spruce and pine monocultures. The production of mature stands ranged from 328 to 479 m3·ha-1. Spruce achieved higher radial growth, but its growth variability was higher than that of pine. Compared to precipitation, temperatures had a greater influence on the radial growth of both tree species, especially in the growing season. In terms of diversity, mixed stands achieved significantly higher structural differentiation and overall diversity compared to monospecific variants. Mixed stands can achieve higher production potential, diversity, and especially resistance to climatic extremes in the lowland regions of the Czech Republic. The differences between mixed stands and monocultures, i.e. the effect of tree species mixing, depend on the appropriate proportions of tree species and their spatial pattern.