Identifying suitable areas for plenter forest management

Plenter forests, also known as uneven-aged or continuous cover forests enhance forest resilience and resistance against disturbances compared to even-aged forests. They are considered as an adaptation option to mitigate climate change effects. In this study, we present a conceptual approach to determine the potentially suitable area for plenter forest management within central European mixed species forests and apply our approach to the case study area in Styria, the south-eastern Province of Austria. The concept is based on ecological and technical-economic constraints and considers expected future climate conditions and its impact on plenter forest management. For each 1 ​ha forest pixel, we assess the ecological conditions for plenter forest management according to the autecological growth conditions of silver fir, and at least one additional shade tolerant tree species. The technical-economic constraints are defined by slope (≤30%) and distance to the next forest road (≤100 ​m) to ensure cost-efficient harvesting. The results show that under current climate conditions 28.1% or 305,349 ​ha of the forests in Styria are potentially suitable for plenter forest management. For the years 2071–2100 and under the climate change scenario RCP 4.5, the potential area decreases to 286,098 ​ha (26.3% of the total forest area) and for the scenario RCP 8.5 to 208,421 ​ha (19.1% of the total forest area). The main reason for these changes is the unfavourable growing conditions for silver fir in the lowlands, while in the higher elevations silver fir is likely to expand. Our results may serve forest managers to identify areas suitable for plenter forests and assist in the transformation of even-aged pure forests to uneven-aged forests to increase resistance, resilience, and biodiversity under climate change.