Climatically Driven Stability in the Alpine/Moorland Boundary on Three Mountains in Southwest Lutruwita/Tasmania 1986–2020
Prepared by Jamie Kirpatrick, Jayne Balmer, Mick Brown, Jenny Styger, and Jennie Whinam
Climate warming is often expected to push alpine vegetation uphill as lowland species move higher and cold‑adapted plants lose ground. To test whether this is happening in Tasmania’s southwest, we revisited long‑term vegetation plots first surveyed in 1986.
We set out to answer three simple but important questions:
- Has the boundary between alpine and subalpine vegetation moved uphill?
- Have alpine-adapted life forms (like cushion plants) declined?
- Have alpine species become less common, or lowland species more common, over time?
To test whether there had been any noticeable climate change impacts in southwest Tasmania, we made use of vegetation monitoring plots that were first surveyed in 1986. These plots were re-located and established as permanent plots in 2010, with the intent of conducting repeat surveys every 10 years. These plots were surveyed for a third time in 2020.
Surprisingly, despite rising minimum temperatures, we found that the vegetation has remained remarkably stable over this period. So, what could account for this lack of change?
We found that, along with increasing temperatures, wind speeds have also increased. In southwest Tasmania, we suspect that the increase in wind is ameliorating any impacts from the increase in temperatures, favouring the low-stature and wind-adapted cushion plants that are already common in the alpine environment.
For the time being, these windy Tasmanian mountains appear to be resilient alpine refuges, where wind exposure may be helping preserve cold‑adapted vegetation despite a warming climate.
This is a plain language summary of the paper by Kirkpatrick et al. published in the Journal of Vegetation Science (https://doi.org/10.1111/jvs.70136)
