Integrative Ecosystem Management Through the Diversification of Structure and Tree Species

The history of systematic forest science is wood-centered, dominated by monospecific stands, and focused on the homogenization of forests. Recently, demands placed on forests have become increasingly extensive and multi-criteria. The agricultural and urban greening sectors are facing similar new challenges, including promoting biodiversity, increasing carbon stock, and improving social services like landscape esthetics, human recreation, and health. In this chapter, first, we demonstrate that diversification of forest structure and mixing of species can improve many ecosystem functions and services including productivity. Thus, diversification paves a way toward integrative forest ecosystem management. Second, we stress the need for additional data in order to establish, plan, and steer more complex forest stands. We also address the need for long-term experiments to acquire better knowledge of structure and growth dynamics of mixed-species stands. We further highlight the need for simulation models for scenario analyses and planning, the need for simplified silvicultural prescriptions to facilitate operational implementation, and the need for teaching, and training tools such as marteloscopes. Third, we show that the size ratio of humans and trees makes forests an ideal system to analyze and model tree-tree interactions, including competition, competition reduction, and facilitation. Recent studies found that competition reduction and facilitation can increase mixed species stand productivity by up to 50%. Structural diversity can improve productivity and is even a better predictor of forest productivity than tree species diversity. Mixed species stands can be more heterogeneous, and their canopies by 10–30% more densely packed, than monocultures. We conclude with our perspective that the biodiversity and health of forests, agriculture, and urban landscapes do not exist in isolation. Rather, there is one overall biodiversity, one carbon cycle, one health, and one sustainability. This suggests a cross-sectoral diversification of structures and species. Recognizing the “One Biodiversity, One Carbon, One Health, One Sustainability” paradigm and re-opening the borders between established sectors to work toward common research, teaching, training, and planning is a promising, innovative, cross-sectoral outlook.