Earlier this year I completed a survey comparing the biodiversity of a grazing system and a nearby roadside verge (PDF).
Many areas of Australia have been negatively affected by the grazing of livestock (Lunt 2012). This study shows that some of this impact may occur during land clearing. A comparative biodiversity method was used to determine the invertebrate and plant biodiversity of a grazing system relative to a reasonably undisturbed area. It was found that the grazing system had a significantly lower plant biodiversity, and a noticeably lower invertebrate biodiversity. In addition, its soil temperature and light intensity were increased, suggesting that shade loss due to tree clearing may play a role in the loss of biodiversity.
Below are images of the area map, light intensity map, temperature (isotherm) map, and transect lines through the two areas. The grazing land is on the left half of each diagram, and the roadside verge on the right hand half of each diagram.
There was a significant difference in biodiversity observed, as the graphs below show.