Plant communities, biodiversity, and forest management

WSL-Institut für Schnee- und Lawinenforschung SLF

10:30 - 11:30

Ort: Englersaal, WSL Birmensdorf (video-link to SLF Davos)

Organisatorin: Rosmarie Büchi

Referent: Prof. Dr. Bernhard Schmid, Remote Sensing Laboratories, Department of Geography, University of Zurich

Moderator: Thomas Wohlgemuth

Sprache: English

At high school, I was fascinated by the possibility that a plant community could be something like a super-organism — the so-called Clementsian view. However, during my studies at university, I quickly learned that plant communities are nothing more than random assemblages of species, corresponding to the so-called Gleasonian view.

With increasing global concerns about biodiversity loss, I joined research programs where we asked what would happen if species would be removed from well-functioning ecosystems. We found that simulated extinctions from such ecosystems lowered their functioning and resilience, indicating that even if they were random assemblages, ecosystems could benefit from the diversity of species within. The likely reason for this is that within a plant community no species can by itself be so variable to take up all resources in a locality. Thus, different species, which by chance differ in their abilities to take up resources, complement each other in the task. However, when we compared this division of labor among species, we found that it was higher for species with a history of co-occurrence than in newly assembled communities. This suggests that communities evolve as predicted by the “Clementsian” view, with far-reaching consequences for ecosystem management.

About the lecturer
Bernhard Schmid started his ecological career working on the life history of Carex flava for his PhD at the University of Zurich. He then moved on to post-doctoral research with two of the leading plant population ecologists of the time, John Harper in Bangor, Wales and then Fakhri Bazzaz at Harvard. He returned to Switzerland as Professor of Conservation Biology at the University of Basel before being appointed Professor of Environmental Sciences at the University of Zurich. He is also an adjunct Professor at Peking University, China.

Bernhard has conducted groundbreaking research in several areas of plant ecology, most notably on the population ecology of clonal plants, mechanisms of competition, community assembly, and more recently on biodiversity–ecosystem functioning relationships. Research pioneered by Bernhard has proved that ecosystems with higher genetic or species diversity are more productive, more efficient and more stable in the face of environmental changes. This discovery countenances for movement away from the dominant use of less diverse systems and monocultures in agriculture and forestry, and towards management for high combining ability among genotypes and species.

Specific research outcomes include: species-rich grasslands have increased productivity and soil fertility if species with high combining ability are used, breeding and genetic engineering for high combining ability among genotypes can break yield stagnation in major crop plants, planting mixed-species forests instead of monocultures can double the amount of fixed carbon per area, and managing for biodiversity provides spatial and temporal insurance for agro- and forest ecosystems.