Exploring the physical properties of Australian alpine soils to inform ecosystem restoration

Abstract

Alpine soils are globally threatened and are particularly vulnerable to the impacts of climate change. In Australia, development and grazing put further pressure on alpine ecosystems. Consequently, land managers and restoration practitioners are increasingly interested in understanding how to tailor revegetation approaches to enhance their success in mountain environments. Because of the intrinsic role of soils in plant-water relationships, the aim of this study was to quantify and compare the physical and hydraulic properties of soils in the Australian Alps. We investigated four common soils that occur across the Australian Alps bioregion: peat soils (organosols), alpine humus soils, skeletal mountaintop soils, and disturbed soils (anthroposols). We quantified and compared soil bulk density, particle density, porosity, water content, infiltration, hydraulic conductivity, and wilting point between soils. We found significant differences in soil properties both within and among each soil, highlighting the importance of understanding local edaphic conditions to improve revegetation outcomes. We recommend that direct measurements of plant establishment, growth, and survival are linked with soil physical, chemical, and hydraulic properties in future research, to build upon these findings.