Twenty Years of Grazing Reduction in Semi-arid Woodlands

Abstract

Twenty year old floristic data were reassessed to determine whether inclusion of remnant non-eucalypt semi-arid woodlands in national parks had enabled recovery from a degraded state, after decades of overgrazing. In Hattah- Kulkyne and Murray-Sunset National Parks (north-western Victoria), landscape condition had substantially improved by 2006. Formerly mobile dune systems in Hattah-Kulkyne are now stabilized by perennial field strata and increasingly dense shrubs (mostly Dodonaea viscosa subsp. angustissima). In Murray-Sunset, chenopod shrubs now dominate and there are signs of regeneration of some of the formerly dominant trees. Semi-arid woodland condition has not (yet) fully recovered, but there are encouraging signs of partial recovery, and indications that further improvements in landscape condition will occur, as long as overgrazing (particularly by rabbits) can be reduced further or maintained at low levels. There are indications that rabbit numbers have greatly increased post-Rabbit Haemorrhagic Disease, threatening the recovery to date.