Simon Leake, Australia’s pre-eminent soil expert, spoke with AKAS Landscape Architecture co-founder Alistair Kirkpatrick about the critical relationship between soil and vegetation, the problems with the commercial soil industry, and the plant and soil knowledge we should expect of landscape architects. He calls for landscape management practices that can allow soil to function and evolve again.
Alistair Kirkpatrick – How important is the relationship between soil and vegetation?
Simon Leake – It’s critical. We’ve got to understand that vegetation makes soil. It’s almost a self-fulfilling prophecy: you start with weathered rock, vegetation grows on it and accumulates nutrients, and those nutrients are recycled back into the topsoil so that the vegetation can accumulate the nutrients it needs. Soil scientists talk about “Jenny’s equation,” which says that soil is a function of the biota – the plants and animals that live on it, the topography, the geography, the climate and, most importantly, time.
Mount Tomah and Mount Wilson in Sydney [Blue Mountains] are located on basalt cap soils. The drive to these basalt caps is through scribbly gum sandstone flora, a low-fertility plant community that is sparse and open. You encounter this wall of magnificent timber when you cross into the basalt geology. This is a prime example of soil and vegetation working together on geology.
How important is it
