The addition of mine waste rock to topsoil improves microsite potential and seedling emergence from broadcast seeds in an arid environment

• Published in: Plant and soil Vol. 440; no. 1/2; pp. 71 - 84
• Main Authors: Golos, Peter J., Commander, Lucy E., Dixon, Kingsley W.
• Format: Journal Article
• Language: English
• Published: Cham Springer Science + Business Media 01.07.2019; Springer International Publishing; Springer; Springer Nature B.V
• Subjects: Arid regions; Arid zones; Aridity; Biomedical and Life Sciences; Blending effects; buried seeds; Distribution; dry environmental conditions; Dunes; Ecology; Emergence; Environmental aspects; hills; Landfills; Life Sciences; Methods; Mine wastes; Mines and mineral resources; mixing; Moisture content; Physiological aspects; Plant Physiology; Plant Sciences; Plant-soil relationships; REGULAR ARTICLE; Restoration; Revegetation; Rocks; seedling emergence; Seedlings; Seeds; Slopes; Soil moisture; Soil Science & Conservation; Soil surfaces; Soil temperature; Soils; Spreading; subsoil; Surface roughness; Surface temperature; Topsoil; Waste management; wastes; Water content; Water depth; Australia; Arid ecosystem; Waste rock dump; Mine site; Restoration ecology
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-019-04060-7

Aims This study investigated the effect of method of blending and spreading topsoil-waste rock (as dictated by waste dump position), rock addition, topsoil source and seed burial on seedling emergence from seeds broadcast onto mine restoration sites. Methods Seed of 10 species were surface sown onto a waste rock dump plateau with six cover treatments spread by loose tipping; three topsoil source treatments (sand dunes, sandplains and stony hills) x two waste rock treatments (topsoil mixed and without waste rock). Results Emergence was greater on the waste dump plateau than slopes, where very few seedlings emerged. On the waste dump plateau, the addition of rock to topsoil increased seedling emergence >2.5-fold. Soil surface temperatures were cooler and water content at a depth of 2 cm was higher in topsoil mixed with rock than without rock. Conclusions Higher seedling emergence with the addition of rock to topsoil was due to the creation of microsites where sub-soil moisture was retained for longer durations. Lack of emergence on waste dump slopes was attributed to relatively low surface roughness that reflected operational issues associated with different methods of spreading and mixing topsoil with rock on plateau versus on slopes.