The area has been described as a natural laboratory for studying the evolution of the eucalypts. This is because there are so many of the different types growing in the Greater Blue Mountains Area. The area shows examples of how the eucalypts have changed to grow in the different Australian environments. These vary from tall forests at the margins or rainforest in the deep valleys, through open forests and woodlands, to shrublands of stunted mallees on the exposed tablelands.