Land use diversity and prey availability structure the bird communities in Norway spruce plantation forests

Abstract

Norway spruce (Picea abies) is one of the most important target trees in forestry. In Central Europe, it is grown primarily in forest plantations. However, the distribution area of this tree species is declining due to climate change and trends toward sustainable forest management. The question how artificial habitats such as plantations influence the native biota is still unclear. We aimed to investigate the influence of spruce plantations on bird communities at the country level. We focused on birds in relation to biotic, stand and land use characteristics. We studied bird communities (including woodpeckers) throughout the Czech Republic. All sites were situated in mature spruce forest plantations. Birds were sampled using the point count method, and nine environmental predictors were considered to potentially affect the bird community. Our results indicate that the representation of deciduous trees (within stands and in the surroundings) and longhorn beetles (as prey) have a predominant effect on the species richness of birds, including woodpeckers. The effects of longhorns and deciduous trees in the stand were positive, while deciduous forests in the surroundings had a negative effect. We also found several species associated with spruce, even in plantation forests. An important finding regarding the future management of spruce stands is that bird communities exhibited a strong relationship with spruce, even outside of its native range. Admixture with deciduous trees was favorable at the stand level, while at the landscape level, there is the need for adequate spruce-dominated forests, and deciduous forests may serve as obstacles. We argue that plantations cannot only be seen as tree farms or green deserts but also be used for biodiversity management. Nevertheless, it is important to leave deciduous trees within the stand until the end of the rotation period, as birds find food and nesting places in these trees.