Setting the scene

About 40 years ago, the first comprehensive biology textbook written specifically for Australian students opened with the photograph in Figure 1.1, showing a flock of sheep in a paddock.

The scene was typical of many agricultural areas in Australia then, and remains so today. The authors commented on the questions a biologist might ask when viewing the picture: why do the sheep prefer to stand in the shade? Why are there no sheep under the far tree? Why are there no young trees in the paddocks? Today, those questions seem less relevant. A contemporary biologist might ask: what was the landscape like before the establishment of European agriculture? What plants and animals have been lost from this area? Are there signs of land degradation and, if so, how could they be reversed? Is the agricultural production sustainable? If not, what are the implications for local human communities? These new questions reveal a growing concern about the impacts of expanding human populations and the application of new technologies on the natural environment.

Chapter aims

This chapter describes how the success of the world's dominant animal species, humans, has severely altered biodiversity and natural ecosystems. Three in-depth examples of environmental problems are introduced, together with an explanation of the knowledge and skills biologists need to reverse or mitigate such problems.