Collateral benefit: unconscious conservation of threatened plant species

Abstract

In Europe, the conservation of rare or threatened plant species (ROTS) largely involves the manipulation of anthropogenic disturbance regimes rather than the mitigation of human-induced threatening processes, as has been the case in Australia. In Tasmania, there are many ROTS, especially those of the depleted and stock-grazed grasslands and grassy woodlands, which survive because, unconscious of the needs of ROTS, people have disturbed land in ways that suit their life-cycle requirements. Such species are found in quarries, in borrow pits, in scrapes, on roadsides, on track edges, on old roads, under introduced trees, in heavily grazed native pastures, in regenerating clearfell coupes and on mown ground. They are disturbance-dependent species, usually with poor competitive abilities. Many cannot survive stock-grazing. Unconscious conservation of these species needs to become conscious, in the European manner. Spatial heterogeneity in disturbance regimes is important for maintaining this set of species, whereas temporal heterogeneity is likely to lead to their doom.