Modelling shepherds’ decision-making about grazing on forested mountain landscapes - contributions for keeping discontinuity

Abstract

Pastoral systems have been key in the sustenance of marginal territories, shaping open areas in forested landscapes by providing important shrub control services. In Serra da Estrela, the largest and highest mountain area in Portugal, livelihoods used to be largely based on the rearing of autochthonous sheep breeds. The mountain’s landscape was, until a few decades ago, composed of large forest patches in a mosaic with open natural pastures. But the grazing pressure in Serra da Estrela has been reducing due to social and economic drivers that have pushed shepherds and sheep to the foothill, or plainly out of the sector. Shrubs start to encroach on previously grazed land and the impacts of the resulting increase in landscape continuity have been made clear in the extreme fires of 2017 and 2022. As fire risk is likely to increase with climate change, it becomes urgent to understand what strategies can be deployed to keep fragmentation in these forested landscapes. However, this discussion often fails to include shepherds’ reasoning to give up seeking altitude pastures. With this study we assessed the variables that can influence shepherds’ willingness to resort to altitude grazing. We used a fuzzy cognitive modelling (FCM) approach. FCM uses fuzzy-graph structures that represent causal reasoning and allow to unveil direct and indirect feedback mechanisms within the system. We drew a cognitive map of the silvopastoral system in Serra da Estrela, including main variables and how they connect, based on local stakeholders’ and experts’ knowledge. Fourteen shepherds were then asked to create their own connections between variables and to provide a value to each connection. With these quantifications, we built an FCM-based scenario analysis to understand what variables are more relevant in generating changes. We expect the results to provide insightful information on which strategies and entities should be involved in keeping altitude pastures open and to inform policy making.