Weeds can cross property boundaries but weed management often cannot. Controlling invasive species across the landscape is therefore not only about the effectiveness of control strategies; it’s also how, when and where those strategies are employed. And these factors are all the result of human behaviour.
We recently modelled the impact of different types of human behaviour together with our ecological understanding of two significant weeds. We wanted to know how the collective decisions of many property managers affected the spread of two damaging weeds: serrated tussock and African lovegrass. We wanted to look at the spread of these two weeds at a large scale and over a longer time period (50 years), and the only practical way to do this was to build a model.
In our model there were 4096 decision-makers who all decided whether or not to control the weed based on a simple rule: if the benefit of controlling the weed was higher than the cost then that decision-maker was more likely to undertake control. If the reverse was true then they were less likely to control.
Using this model we could change aspects of the behaviour of the decision-makers. Our model wasn’t perfect, but it was detailed enough to give us an idea of how the behaviour of multiple land managers might affect the spread of weeds.
Differences in the impact and ease of control...
