RCAAE members John Morgan and Susanna Venn recently re-sampled the world’s oldest snowfence experiment at Old Man Range, South Island in New Zealand. Established in 1959 by Sir Professor Alan Mark (University of Otago), the snowfence structure changes the extent and duration of snowcover on a small area of windswept cushionfield. Over time, species composition has changed, as well as species cover. The cushionfield has re-assembled into a snowpatch community dominated by herbs that are rare in the broader cushionfield landscape. While the accumulation of snow is counter the prediction for many alpine areas (such as Australia – where loss of snowcover is predicted to occur over the coming century), this experiment beautifully illustrates the importance of growing season length and moisture on the distribution of alpine plants. In the Australian context, the loss of snow is likely to lead to the range contraction of species that are restricted to such areas.
Susanna and John will analyse the changes in species composition over time using a plant functional trait approach. What is it about plants – their height, specific leaf area, leaf nitrogen – that allows them to increase in late-lying snowbanks compared to the exposed cushionfields. They will then compare the findings of the Old Man Range snowfence experiment with changes they have been observing at Niwot Ridge in Colorado, USA where a similar experiment has been running since 1994.
You can read more about the changes in vegetation at the Old Man Range at:
Mark et al. (2015) Ecological responses to 52 years of experimental snow manipulation in high-alpine cushionfield, Old Man Range, south-central New Zealand. Arctic, Antarctic, and Alpine Research 47, 751-772.