Topsoil Handling and Storage Effects on Woodland Restoration in Western Australia

Abstract

An analysis of the effects of topsoil handling and storage methods was undertaken to optimize the potential rehabilitation of southwest Western Australian Banksia woodland species present before site disturbance. An increase in the depth of topsoil stripped from the Banksia woodland, from 10 to 30 cm, correlated to decreasing seedling recruitment from the soil seedbank by a factor of three following in situ respreading in an area to be restored. There was no significant difference in total seedling recruitment in situ at two depths of spread, 10 cm and 30 cm. These results concur with an ex situ trial on the effects of depth of seed burial on seedling recruitment that showed most species failed to emerge from depths greater than 2 cm. In situ stockpiling of the woodland topsoil for 1 or 3 years demonstrated a substantial and significant decline in seedling recruitment to 54% and 34% of the recruitment achieved in fresh topsoil, respectively. Stripping and spreading during winter substantially depressed seedling recruitment, compared with autumn operations, as did in situ stockpiling followed by spreading in the wet season, or stockpiling in winter followed by spreading in spring. No loss in total seedling recruitment occurred when replaced topsoil and subsoil were ripped to 80 cm following spreading of topsoil in sites to be restored. Conclusions from this study are that (1) topsoil provides a useful source of seeds for rehabilitation of Banksia woodland communities in the southwest of Western Australia, (2) correct handling of the topsoil, stripped and replaced fresh and dry (autumn direct return) to the maximum depths of 10 cm, can be used to optimize revegetation of species‐rich plant communities with this type of seedbank, and (3) ripping of topsoil and subsoil to ease compaction of newly restored soils does not diminish the recruitment potential of the soil seedbank in the replaced topsoil.

Comparison of translocation methods to conserve metallophyte communities in the Southeastern D.R. Congo

“…Although topsoil spreading has been demonstrated to be a successful restoration method for temperate vegetation communities and ecosystems (Good et al 1999;Rokich et al 2000;Vécrin and Muller 2003;Jaunatre et al 2012), this technique does not appear to be effective for the conservation of Cu-Co communities. After two years, topsoil spreading communities did not tend to become similar to the reference ecosystem.…”

Forest restoration following surface mining disturbance: challenges and solutions

“…Oil sands sites reclaimed using forest floor material (vs. peat-mineral mix) had higher cover of trees, shrubs, and forbs, and the soil microbial community composition was converging more quickly towards that of natural upland forest (Hahn and Quideau 2013). Plant propagules in forest floor material lose their viability quickly if the material is stockpiled prior to placement but direct placement of forest floor material can overcome this problem and has shown promise in trials in several different locations (Holmes 2001;Iverson and Wali 1982;Koch et al 1996;Rokich et al 2000;Tacey and Glossop 1980). For example, direct placement of forest floor material on a coal mine reclamation site in Alberta resulted in rapid (B3 year) establishment of 65 native species, 30 of which were characteristic of mature, closed boreal forest (Macdonald et al 2015).…”

Structural development of vegetation on rehabilitated North Stradbroke Island: Above/belowground feedback may facilitate alternative ecological outcomes

“…While this strategy is often used to reintegrate native seed and soil-microbial components into the rehabilitated ecosystems (Rokich et al 2000), the practice of stripping and stockpiling topsoil renders the reconstructed soils relatively more susceptible to weathering and loss of biotic viability (Abdul-Kareem and McRae 1984;Koch et al 1996). This should account for the generally lower soil fertility parameters found among the rehabilitated vs. reference sites (e.g., total carbon content, total nitrogen content, soil-nutrient content and holding capacity).…”