The Effect of Timing of Rehabilitation Procedures on the Establishment of a Jarrah Forest After Bauxite Mining

Abstract

The restoration of the high botanical diversity of the premining jarrah (Eucalyptus marginata) forest is a major priority of rehabilitation following bauxite mining in southwestern Australia. This study investigated the effects of different ripping, seeding, and scarifying dates on the establishment of plants from propagules stored in the topsoil and from applied seed on areas being rehabilitated after mining. Seed stored in the topsoil, rather than applied seed, was the major contributor to plant diversity. Ripping late (April) or scarifying in June significantly reduced the number of species and numbers of individual plants that established from propagules in the topsoil. Species originating from broadcast seed were most numerous when the seed was broadcast in April or after scarifying in June. Scarifying before seeding, particularly in June, increased the establishment of species from the broadcast seed. To make best use of the applied seed, without jeopardizing the establishment of species from the topsoil, pits should be ripped and sown by April. We list a number of strategies that can help maximize plant numbers and botanical diversity on rehabilitated bauxite mines, which may also be of more general application for restoring the original native vegetation on disturbed sites.

Roadfill Revegetation in Semiarid Mediterranean Environments. Part II: Topsoiling, Species Selection, and Hydroseeding

“…In previous studies, topsoil spreading improved vegetation cover in two ways: by improving soil properties (Cotts et al 1991; Harwood et al 1999; Balaguer 2002) and by providing a soil seed bank (Ward et al 1996; Rokich et al 2000; Holmes 2001). In our study, the differences in soil properties (except nitrogen content) between the topsoiled and the nontopsoiled plots were low and not significant.…”

Restoring a Jarrah Forest Understorey Vegetation after Bauxite Mining in Western Australia

“…In the jarrah forest of Western Australia the soil seed bank ranges from several hundred up to about 1,500 native seeds/m 2 (Tacey & Glossop 1980; Vlahos & Bell 1986; Koch et al 1996; Ward et al 1997; Smith et al 2000). For bauxite mine restoration the soil seed bank can contribute more than 70% of the plant species richness (Koch & Ward 1994; Ward et al 1996) and hence is an important resource for the restoration process. Studies have quantified the seasonal changes in the seed bank (Table 4; Ward et al 1997), the depth distribution of the seeds (Koch et al 1996), the ability of germinating plants to emerge from various levels of burial (Grant et al 1996), and the effects of different soil handling procedures on the seed bank during bauxite mining (Koch et al 1996; Ward et al 1996).…”

Primary and repetitive secondary somatic embryogenesis of Lepidosperma drummondii (Cyperaceae) and Baloskion tetraphyllum (Restionaceae) for land restoration and horticulture

“…The dryland sedges of the jarrah forest are considered "recalcitrant", as during mine site rehabilitation they are not easily re-established from the returned topsoil seed bank or from broadcast seed (Ward et al 1996). In addition, although there are many attractive, droughttolerant species, they are not available in horticulture because of propagation difficulties.…”