Climate change: Frequency of warm-adapted alpine plants may decrease in warming world

For alpine plants — such as the alpine pink or the dwarf soapwort — future climate warming may lead to reductions in the number of plants within each species adapted to warmer weather, according to a modelling study published in Nature Climate Change. This potential maladaptation could further increase the risk that these plants face as their geographical ranges shift owing to climate change.

As temperatures shift with climate warming, local species of plants may face extinction, adapt to new conditions, or track the changing climate. Studies predicting the future migration needs of different organisms generally treat species as a single unit with an optimal temperature range that suits their growth and survival. This range, however, largely ignores within-species (intraspecific) variation.

Johannes Wessely and colleagues developed a model that considered intraspecific variations in the climate tolerance of six species of alpine plants (including the alpine pink, the dwarf soapwort and the long-nosed lousewort) from the European Alps to understand how they will respond to climate warming in the twenty-first century. Consistent with previous research, the model predicts losses in the geographical range of each species, irrespective of intraspecific variations. For five species (excluding the alpine pink or Dianthus alpinus), however, a decreased frequency in the proportion of plants that are genetically adapted to warmer temperatures is predicted with climate warming. This counterintuitive phenomenon is likely driven by leading-edge colonization and priority effects. In other words, cold-adapted plants already found at the leading edge of a species’ geographical range can expand into uncolonized territory, however they might also impede the establishment, and therefore survival, of warm-adapted plants as the climate shifts.

This study not only reveals the potential for maladaptation, but also that accurate predictions of the effects of climate change could be underestimated if local adaptation and variation within species are not considered.