Weed management is not quite 'Bush Regeneration'-An opinion

摘要

As long-term practitioners of managing weeds in varied circumstances, we notice the increasing trend towards bush-regeneration as a broad approach to weed management, particularly in New South Wales (NSW). Recent observations in the Sydney basin and other parts of NSW show that bush-regeneration has not achieved the desired weed control outcomes for major weed species that have plagued eastern Australia for decades. These include semi-terrestrial species - alligator weed (Al-ternanthera philoxeroides(Mart.) Griseb), primrose willow (Ludwigia peruviana (L.) Hara), long-leaf willow primrose (Ludwigia longifolia (DC.) Hara), and full-terrestrial species such as blackberry (Rubus fruiticosus L. species aggregate), Chilean needle grass (Nassella neesiana (Trin. & Rupr.) Barkworth), Coolatai grass (Hyparrhenia hirta (L.) Stapf) and green cestrum (Cestrumparqui L'Her.). Added to this are infestations of: interstate invaders such as golden wreath wattle (Acacia saligna (Labill.) H.L. Wendl.); fully aquatic invaders, such as egeria (Egeria densa (L.) Planch); and terrestrial invaders expanding their range southwards, such as groundsel bush (Bac-charis halimifolia L.). Following an initial survey in 2009, we now observe these weeds greatly expanded invading new areas. We attribute inadequate local control primarily to the change in approach adopted by some agencies: i.e. a greater portion of funding used for bush-regeneration, instead of, as previously, weed management. We appreciate the noble goal of bush-regeneration, that is to assist regeneration of native bushlands from a diminished quality to a better condition. However, we lament the techniques used have limited value in controlling the large-scale infestations of highly invasive weeds. Indeed, the adoption of bush-regeneration as the primary paradigm for funding appears to be self-serving for some stakeholders. We suggest that well-coordinated, direct control, deployed on a regional-, catchment- and local-site-scale, is the only way to contain highly invasive weeds. We contend, that unless there is a change in weed management investment, these well-known invaders will soon become so entrenched that they will become widespread and likely to be given lower priority for management.