From monocultures to mixed-species forests: is tree diversity key for providing ecosystem services at the landscape scale?

• Published in: Landscape ecology Vol. 32; no. 7; pp. 1499 - 1516
• Main Authors: Schuler, Laura J., Bugmann, Harald, Snell, Rebecca S.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.07.2017; Springer Nature B.V
• Subjects: Alpine regions; Biodiversity; Biomass; Biomedical and Life Sciences; Climate change; Climate models; Climatic conditions; Computer simulation; Dominant species; Ecology; Ecosystem services; Ecosystems; Environmental changes; Environmental conditions; Environmental impact; Environmental Management; Environmental quality; Forest productivity; Forests; Gravitation; Gravity; Hazards; Landscape; Landscape Ecology; Landscape/Regional and Urban Planning; Life Sciences; Mixed forests; Monoculture; Nature Conservation; Plant diversity; Plant populations; Plant species; Provisioning; Research Article; Resilience; Scale (ratio); Species composition; Species diversity; Sustainable Development; Trees; Valleys; PROMETHEE; Landclim; Plant functional traits; Multispecies; Natural hazard; Horizontal structure; Vertical structure; Montane forests; Monoculture
• ISSN: 0921-2973; 1572-9761
• DOI: 10.1007/s10980-016-0422-6

Context Converting monocultures to mixed-species stands is thought to be a promising approach to increase forest productivity and resilience, while additionally providing other ecosystem goods and services (EGS). However, the importance of tree species composition and structure remains unclear, particularly beyond the stand scale due to the difficulty of conducting comprehensive, long-term experiments. Objectives To compare the ability of different tree species mixtures to provide various EGS at the landscape scale. Methods We used a dynamic forest landscape model to simulate all possible combinations of dominant tree species for two landscapes; a high-elevation alpine region (Dischma valley, Switzerland) and a lowland valley (Mt. Feldberg, Germany). We evaluated multiple EGS, including protection from gravitational hazards, aboveground biomass, and habitat quality, and examined trade-offs and synergies between them. Results Mixed-species forests were usually better in providing multiple EGS, although monocultures were often best for single EGS. The simulation results also demonstrated how changing environmental conditions along an elevational gradient had a strong impact on the structure of different species combinations and therefore on the provisioning of EGS. Conclusion Tree species diversity alone is not a good predictor of multifunctionality. Mixtures should be selected based on local environmental conditions, complementary functional traits, and the ability to provide the EGS of interest. Although our work focused on current climatic conditions, we discuss how the modelling framework could be employed to consider the impacts of climate change and disturbances to improve our understanding of how mixed-species stands could be used to cope with these challenges.