We know that climate change poses an existential threat to the mountains that we know and love.
A new study, looking at 36 species of alpine plants, looks at one aspect of the changes that are already underway. It shows that ‘elevational shifts’ are occurring rapidly in the Australian alpine zone. Plants are moving higher (a number are also moving downslope) to find optimal conditions to grow. The authors of the report Alpine plants are on the move: Quantifying distribution shifts of Australian alpine plants through time say that ‘this may allow species to persist under climate change. However, if current warming trends continue, several species within the Australian alpine zone will likely run out of suitable habitat within a century’.
The authors are Jennifer Auld, Susan E Everingham, Frank A Hemmings and Angela T Moles.
They are part of the Big Ecology Lab (bigecology.com.au) at the University of New South Wales, Australia. One aspect of research in the Big Ecology Lab focuses on plant responses to climate change, particularly, quantifying if plants have already been responding to changes in climate in the past.
Alpine plant species’ distributions are thought to have been shifting to higher elevations in response to climate change. By moving upslope, species can occupy cooler and more suitable environments as climate change warms their current ranges. Despite evidence of upslope migration in the northern hemisphere, there is limited evidence for elevational shifts in southern hemisphere plants. Our study aimed to determine if alpine plants in Australia have migrated upslope in the last 2 to 6 decades. It looked plants within Kosciuszko National Park.
How did they conduct their research?
We collated historic occurrence data for 36 Australian alpine plant species from herbarium specimens and historic field observations and combined these historic data with modern occurrence data collected in the field.
The researchers found that Eleven of the thirty-six species had shifted upslope in mean elevation and four species showed downslope elevational shifts.
Alpine ecosystems are considered to be particularly at risk under future climate change due to their high climate sensitivity and large numbers of endemic and threatened species. Identifying which species are shifting their distributions can help us to predict which species would benefit most from higher intervention conservation methods such as assisted colonization to help species migrate across isolated and fractured landscapes. Our findings also suggest that future climatic warming could result in more species elevational shifts, which in turn could lead to large changes in ecological community dynamics, for instance, by changing the suite of interacting species present in different regions. We still have much to learn about the likely impact of this world changing process on our precious alpine plant communities.
The report can be found here.