ASPECT AFFECTS VEGETATION SUCCESSION AFTER TREE CLEARANCE IN A GRASSY WOODLAND IN TASMANIA

Old field succession is the process of vegetation recolonisation of abandoned sites in a passive method of restoration. Slope aspect could be expected to affect the nature of succession after clearance. We investigated variation in paired cleared and uncleared plots between three aspects in grassy woodland in northeastern Tasmania. PERMANOVA was used to assess relationship of species composition to clearance status, site aspect, their interaction, soil depth, litter cover, bare ground cover, rock cover and wood cover. Ordination was used to visualise similarities between combined aspect and clearance classes. Chi-squared was used to test for deviation of frequency of species between the aspect and clearance classes. Basal area of trees was tested for differences between clearance and aspect combinations. It was found that aspect, clearance, woody debris and rocks all affected species composition. An interaction between aspect and clearance class indicated that responses to clearance were influenced by aspect. Vegetation was most similar between clearance classes on the northwest aspect, where Acacia mearnsii was abundant, but limited on other aspects. Because the cleared area was not ploughed or fertilised, native grass and herb species persisted well on all aspects, making the cleared area as valuable for nature conservation as the uncleared area.