The newsroom tends to overstate things at times to play at the emotion of the audience. From welcoming insect overloads to announcing a killer storm, this kind of language often misrepresents facts and feeds the population crap disguised as news. Bloody Murdock press am I right!
But I digress…. Science is sometimes accused of doing the same thing. When referring to the expansion of a native shrub into an area it didn’t previously occur, you could be forgiven for assuming there are massive impacts when words like invasion are used instead of something like encroachment.
But invasion is the accepted terminology to describe a species that has spread beyond its native range (thanks to something humans have done) and has come to dominate its new range with high numbers (and may have some impacts). Check out my paper about Coast Tea-Tree (THE SCIENCE vs THE BLOG)
Ok. So I guess the debate it about impacts…. maybe. Best measure some impacts then! Remember, we should not be assuming. Given there are some pretty significant structural changes in an area that shrubs have encroached, animals using those areas should be impacted right?
That’s what Bron the reporter and her crew thought when they went into the Coranderrk Bushland Reserve – which has seen the shrub Kunzea (Yarra Burgan) encroach over the last 20 years. They set up their cameras to take photos of all the mammals. And did they find native mammals were impacted by this invasion? Well…. Nope.
Pretty much nobody cared either way. Most species were responding to other vegetation properties like the amount of grass or understory cover. Not Kunzea. Well, swamp wallabies seemed to stay out of it at night, but that was it. Everyone else just did their thing.
For the actual science of this story, you should definitely read the paper and contact the authors if you have any questions.
Hradsky BA, Loschiavo J, Hradsky M & Di Stefano J (2015) Shrub expansion alters forest structure but has little impact on native mammal occurrence. Austral Ecology 40: 611-624.
K!E14 by Luke S. O’Loughlin