Why is the invasion of native plant communities by exotic perennial grasses a threat to biodiversity?
Since 1788, many perennial grass species have been introduced to Australia. Some species have adverse impacts on biodiversity and agriculture and are recognised as weeds. For example, the Commonwealth Government has listed serrated tussock and Chilean needlegrass as two of 20 Weeds of National Significance. In NSW, these species and pampas grass, giant Parramatta grass, African lovegrass and giant rat’s tail grass have been listed as noxious weeds for parts of NSW under the Noxious Weeds Act.What are the impacts of some exotic perennial grasses on biodiversity? Increasing evidence that some perennial grass species have significant adverse impacts on biodiversity has led to the listing of ‘invasion of native plant communities by exotic perennial grasses’ as a key threatening process. A few examples follow: • Coolatai grass grows vigorously, forming an almost complete monoculture and replacing native grass and wildflower species. It tolerates drought, heavy grazing and many herbicides. I
