Forests provide biodiversity, ecosystem functions, income and much more. How can these diverse and seemingly diverging demands be met? An international research team led by the University of Göttingen addressed this question by analysing the effects of enriching beech forests in Germany with commercially valuable native (to mountainous regions of Europe) and non-native conifer species, in this case, the Norway spruce and Douglas fir, respectively. Their study showed that enriching beech forests which naturally have few tree species does not necessarily reduce species richness or ecosystem functioning. In fact, their results showed that there were positive gains at many levels including biodiversity, ecosystems and economic viability, especially for the combination of beech with Douglas fir. The research was published in Science Advances.
The scientists used a unique empirical dataset, taking data from 40 plots of mature European beech forests across the state of Lower Saxony in Germany. The research team combined data from 11 projects, each of which analysed many different research aspects of European beech forests enriched with conifers. These aspects included: seven biodiversity indicators, considering arthropods and birds in the canopy to fungi and creatures in the soil; eight ecosystem functions, including processes involved in nutrient cycling, such as the amount of carbon or nitrogen in the soil or the biomass of the trees aboveground; and six economic functions, such as current and short-term economic return, tree survival and volume of wood in the future. The research gave a unique and comprehensive perspective by integrating these multiple perspectives.
The results showed that mixed forests with beech and Douglas fir have enhanced biodiversity and ecosystem functioning while improving the economic performance compared to monocultures of beech. "There are, of course, major concerns about the potential risks to the environment of introducing non-native species," explains Dr Larissa Topanotti, "but our research showed it can be possible to do this to the benefit of biodiversity, ecosystems and economics: it was a win-win-win situation. However, the right species for the environment, the spatial scale and the existing forest need to be carefully considered."
"Increasing the range of species to include more native species and trees species that can adapt to climate change is essential for the future," explains Dr Nathaly Guerrero-Ramírez. Professor Carola Paul adds: "Our study has contributed to finding compromise solutions to manage the increasingly diverse demands on forests and forest management by society."
This study was made possible thanks to the German Research Foundation (DFG).
Original publication: Topanotti et al: Enhancing economic multifunctionality without compromising multidiversity and ecosystem multifunctionality via forest enrichment, Science Advances 2024. Doi 10.1126/sciadv.adp6566
