I know this may seem like my favorite topic, but invasive species are not just our problem in the northeast, or even the United States. I will be visiting Australia in a couple of weeks where my daughter will be starting grad school. I wondered what kinds of problems there were with invasive species down under. “There are now more foreign plants in Australia than native ones – at least ones we know about, say scientists. About 27,500 introduced plant species have made their way into the country, compared to our 24,000 natives” according to the Australian Department of the Environment. Not all of these species are invasive, but in looking over the plant list, there were a few species that were familiar. Prickly Pear (Opuntia) which is considered endangered in Massachusetts – but in Australia it takes over large areas and prevents native species from competing. It is a problem in pastures and natural habitats alike. It apparently also harbors European rabbits – another problem species on the continent down under.
Looking at the other side of the coin – a tree species spreading on the west coast comes from Australia. Australia is covered with unique forests of Eucalyptus trees. They provide habitat for many of the unique birds and mammals found in Australia. As with many of our invasive plants, someone thought it was a good idea to bring from the dry south west portion of Australia to the dry American west.
[lightbox link=”http://norcrosswildlife.org/wp-content/uploads/2016/01/eucalyptus.jpg” thumb=”http://norcrosswildlife.org/wp-content/uploads/2016/01/eucalyptus-300×198.jpg” width=”300″ align=”left” title=”eucalyptus” frame=”true” icon=”image” caption=””]The river red gum (Eucalyptus camaldulensis) is one of the most widely planted eucalyptus in the world. The tree produces welcome shade in the extreme temperatures, and plays an important role in stabilizing river banks, holding the soil and reducing flooding. It cold hardy and very fast growing – it can grow as much as 6-12 ft. per season. In Australia it is the nesting home of the superb parrot, a threatened species. In California its habit of dropping branches increases the fire load and leads to catastrophic fires. It shades and crowds out native trees. Although it is not considered the most invasive plant that has come from Australia (coast burnweed and Australian saltbush take that prize) it tolerates the drought and current heavy rains that California is experiencing. Exotic plants are often new and curious additions to our gardens, but we need to be vigilant to prevent the introduction of fast-growing, easily adaptable species.
