Weeds and feral animals are invading mountains
Alpine areas are amongst the least invaded ecosystems in Australia. This, in part, is because the environment is likely to be too harsh for many introduced species to survive. However, it may simply be that many species have yet to arrive. Our research has shown that the flora and fauna of the Bogong High Plains, and other alpine summits, is rapidly changing. Weed surveys have identified that many species have made the jump from the lowlands to the alpine regions. In some cases, this has occurred because they have been deliberately introduced into ski resorts. The introduction and spread of Orange Hawkweed is a good example of this. Other species are so widespread that their control will be difficult – Ox-eye Daisy is now so common in subalpine woodlands near Mt Hotham that it is likely have substantial ecological impacts.
Many new arrivals, however, have moved into the mountains by using roadsides as corridors for dispersal. Some, such as Chilean Needle Grass, have never been seen before in the alps until their detection on roadsides near Falls Creek. Others, such as Sweet Vernal Grass and St John’s Wort, are rapidly expanding their range, using roadsides and walking trails as initial points of introduction into native vegetation.
And it’s not just weeds that are proliferating. Deer have been detected in all localities of the endangered plant community known as ‘snowpatch’ on the Bogong High Plains and are increasingly common above the treeline in places such as Mt Howitt. Just five years ago, there was almost no evidence of their presence. Some invaders are not so obvious. European bees are now common, feeding on the pollen of native and introduced plant species at some of the highest summits. Introduced slugs and earwigs have been recorded in alpine areas, as have vertebrate pests such as rabbits, horses and starlings.
Ox-eye (Leucanthemum vulgare) is now well-established in woodlands near Mt Hotham.