(MAL)ADaptation to human pressures

We started following dewy pine individuals across southern Spain in 2011, as part of Maria Paniw's PhD project. By now (2023), we have collected demographic data on > 7,000 individuals. This research is conducted in close collaboration with the FEBIMED group at UCA.

Initially, research on dewy pines focused on population dynamics under disturbance interactions. Dewy pines are endemic to Mediterranean heathlands where fire is an intrinsic element. In natural heathland habitats, dewy pines reach highest population densities in early-post fire habitats. Throughout the range of the species, however, fires have been largely replaced by low-impact anthropogenic disturbances (e.g., browsing); but such disturbed sites do burn occasionally. We initially therefore asked: 

How do the interactions of different disturbance stressors affect dewy pine population dynamics?

Stochastic structured population models clearly showed that dewy pines behave as a fire-adapted, early-successional species in natural heathlands, and that human disturbances fundamentally change population dynamics and selection pressures. Both frequent interactions of fire & browsing and high levels of browsing (even in the absence of fire) may cause local extinction. These results emphasize the importance of studying interactions of different environmental drivers on population dynamics - particularly as human pressures are increasing in a wide range of ecosystems!

Have plants adapted to novel anthropogenic habitats? What are the population consequences under climate change?

Intrigued by the marked differences in population dynamics between fire- and human-disturbed sites, we started following more individuals in severely chronically disturbed sites since 2016. Combining field censuses and greenhouse experiments, we are investigating whether plants have adapted to the anthropogenic habitats, and, if so, what these adaptations mean for population persistence under climate change. 

What can a spatially explicit population model reveal about viability under environmental change?

The dewy pine has also become a model system in the SNF project "Population persistence under environmental change across space and time: a unified framework" in collaboration with the University of Zurich. 

What is the role of trade-offs in shaping population dynamics?

In heavily disturbed sites, individuals delay reproduction and seem to trade off growth and reproduction. We are currently investigating the implications for viability analyses.