Establishing a monitoring program for Tasmania's montane conifers

Abstract

Tasmania’s relictual cool temperate conifer flora is at risk from projected climate change during this century. Montane and rainforest conifer species exhibit several characteristics which indicate likely vulnerability to environmental change. They are adapted to cool and wet conditions and are highly sensitive to drought and fire. Increased moisture stress and fire are therefore expected to drive declines and local extinctions in these species with ecosystem-changing consequences. A long-term monitoring program has been established to examine trends in condition and recruitment for four Tasmanian endemic conifer species. Permanent monitoring sites have been established at 13 locations in Tasmania’s highlands. The target species include two long-lived, slow-growing rainforest tree species – Pencil Pine (Athrotaxis cupressoides) and King Billy Pine (A. selaginoides) – and two shrubby conifers typically associated with high elevation coniferous heath vegetation – Dwarf Pine (Diselma archeri) and Drooping Pine (Pherosphaera hookeriana). Conifer condition was assessed visually using four condition classes. Presence of juvenile plants was recorded as were cones (strobili) on mature plants. Conifers were mostly in good condition, with Drooping Pine the only species to frequently exhibit poorer condition. Condition varied significantly between sites for Pencil Pine but not for King Billy Pine. No recruitment of Pencil Pine was evident at the majority of its sites (23 of 34), whereas seedlings and juveniles were present at most King Billy Pine sites (20 of 24). Recruitment appeared to be more or less continuous for the shrubby conifer species.