Pattern and long-term changes in pasture-woodlands: Complex interactions in a traditional type of agro-forestry

Pasture-woodlands Photo: V. Barbezat (WSL)

A project within the NCCR Plant Survival, University of Neuchâtel

Most types of pasture woodlands in Switzerland and elsewhere in Europe suffered a dramatic decline during this century. Initially this was due to intensification; more recently the decline has been caused by extensification of agricultural management. Although in former times pasture woodlands were widespread and probably the most abundant type of man-made landscape, presently they are rare and persist primarily by the grace of conservation initiatives. This project will focus on the evolution of a type of pasture woodland typical of the Jura mountains: the "Pâturages boisées". They are considered of medieval origin and result, in terms of modern ecology, from a specific disturbance pattern. In particular, we aim to understand long-term effects of the traditional agro-forestry activities on the ecological resilience, functional diversity, sustainability, and conservation value of the pasture woodland ecosystem.

Summarising, the research questions of the project are threefold:

• Do interactions between trees and unpalatable herbs and shrubs (facilitator species) determine the structure, dynamics and plant diversity of pasture woodland ecosystems?
  
• Do sites with historically low disturbance regimes shelter a higher diversity (species richness and genetic diversity) of tree-dependent species? If so, what are successful survival strategies of these species (epiphytic lichens) in a dynamic habitat?
  
• Can changes in abundance of trees and facilitator species be traced and quantified in the pollen records; more particularly, are periods of high local tree abundance correlated with a low abundance of unpalatables, and in which way is biodiversity correlated with these fluctuations?

The answers to these questions will allow us to develop strategies for the conservation of the dynamics of species-rich and diverse pasture woodland ecosystems. This project implements general findings of the NCCR Plant Survival to the landscape level and develops spatially explicit dynamic models of natural and anthropogenic long-term impacts on mutualistic and antagonistic plant-plant interactions.

Participants

Contact

• Christoph Scheidegger