Landscape transformations following blackberry decline in the south-west of Western Australia : successful restoration or back to blackberry ?

In recent years there has been a rapid decline in blackberry (Rubus anglocandicans A.Newton) populations along waterways within the Warren Catchments region located in the south-west of Western Australia. The soil pathogen, Phytophthora bilorbang S.Aghighi, G.E.S.J.Hardy, J.K.Scott & T.I.Burgess, is thought to be instrumental in the decline of these populations. For most waterways in the region, blackberry has dominated the forest understorey for decades. Consequently, the weed’s rapid decline typically results in areas of bare soil or grassed landscapes lacking structure. The blackberry decline created the opportunity to access and restore what were previously often inaccessible but, with the exception of blackberry, fairly pristine landscapes. However, the post-decline absence of blackberry plants within impacted populations is not absolute; scattered individuals persist. Moreover, the decline is not known to impact on what could be a significant blackberry seedbank. Without intervention to restore the landscape, therefore, new blackberry individuals or other weed species could just replace the previous blackberry infestations. Consequently, a follow-up restoration project is underway to increase the resilience of the post-decline community to future weed invasion, including possible blackberry re-invasion. Here we outline the efforts being undertaken to understand these threats and to encourage the successful restoration of these areas within the Warren Catchments region.