We  bang on a lot about weeds...[well I do...!].. .but why? Sure they can be a nuisance...like cobblers pegs getting stuck in your socks...but do they really cause a problem? We do know that weeds cost Australians lots of money in control and lost production...it is generally agreed that weeds cost the agricultural sector alone over 4 billion dollars per year. Certain species of weeds do not get a great deal of publicity, but have a serious effect on our nations biodiversity. Weeds can been loosely defined as "a plant growing where it is not wanted". This works, but I tend to think a weed is serious when it upsets the balance of an ecosystem. Weeds behave much like a school bully...they out-compete our native plants and can easily form mono-cultures.

The problem with mono-cultures, be they forestry, agriculture or a severe weed infestation, is that they do not provide a variety of habitat and food source for our native animals. Indeed, one of the problems with weeds is that they tend to have a competitive advantage over native species in that they do not have their predators in this country.There are many weeds that affect our native fauna, but I will talk about three of these thugs today. These species are sometimes called "transformer" species in that they completely alter an ecosystem.

Singapore Daisy

The first one that comes to mind is Sphagneticola trilobata, or Singapore daisy, which would be no doubt familiar to many readers. Recently a frog survey was done at Seaview Terrace by Ed Meyer, which recorded frog calls from a wetland that runs from Noosa National Park to Sunshine Beach. The top [western] end of this watercourse is in reasonable condition. The eastern end is completely choked out with Singapore daisy. The results of the survey showed good populations and varieties of frog species in the good part, with very few being recorded under the mats of Singapore daisy.

Singapore daisy is reproduced both by seed and vegetatively. You can see the extent of the infestation in the photo.

Cat's Claw Creeper

Another nasty is Macfadyena unguis-cati or Cat's claw creeper. This villain, introduced as an ornamental plant, produces thousands of paper like seeds which are distributed both by wind and water. It is particularly bad in riparian [creek] areas. It also develops a large underground tubers which makes treatment very difficult. Cat's claw climbs over native vegetation and smothers them. Over a period of time this can kill all the native plants and you are left with just Cat's claw.

 Cat's Claw Creeper - smothering everything

Cat's Claw Creeper Tubers

Silver Leaf Desmodium

Velcro, glue vine or Silver leaf desmoduim [Desmodium uncinatum] is a particularly nefarious weed. Introduced as cattle fodder, it has become a pest particularly in hinterland areas. As more people move to our region, cattle are being removed from properties and this plant is quickly establishing. Whilst Silver leaf desmodium does not smother like Cats claw, it has a more insidious effect on fauna, particularly frogs. As the name [Velcro/glue vine] suggests, this plant is covered in fine hairs, allowing it to climb, and stick to cloths...or for things to stick to it. Frogs get into real trouble with this one. They rest on the leaves and stems in the cool mornings, only to be trapped. As the sun rises they dehydrate, and die.

Frog trapped by Silver leaf desmodium - dehydrated in the morning sun. Photo by Daniel Cox, courtesy of Eva Ford at MRCCC

And I haven't even mentioned the aquatic weeds! Try to learn about weeds in your local area and get rid of them...you will be doing our Biosphere a favour...including it's inhabitants.