AbstractsBiology & Animal Science

The soil of abandoned farmland, Cumberland Plain Woodland and restored vegetation : implications for the restoration of an endangered ecological community

by Jennifer K. Fitzgerald

Institution: University of Western Sydney
Department: School of Natural Sciences
Degree: PhD
Year: 2009
Keywords: Cumberland Plain (N.S.W.); farmlands; soils; soil ecology; plant-soil relationships; forest regeneration; revegetation; New South Wales
Record ID: 1069597
Full text PDF: http://handle.uws.edu.au:8081/1959.7/489752


The restoration and management of Cumberland Plain Woodland, an ’Endangered Ecological Community’ found only in western Sydney, has occurred without a sound understanding of soil-vegetation relationships within this community. Since 1992, large tracts of abandoned farmland, which were originally covered with Cumberland Plain Woodland, have been planted with native trees and shrubs to facilitate woodland development. This approach was based on the theory of (small-scale) patch dynamics since it was envisaged that the developing overstorey would facilitate changes to the soil environment, which would advantage native woodland species and disadvantage exotic pasture species. To date, this approach has had limited success and importantly, the restoration of Cumberland Plain Woodland has ignored: (a) characterisation of the soil environment; (b) how different patch types (e.g. tree and shrub) influence the soil; (c) how past land use has affected the soil; and (d) the effects of revegetation on soil properties and processes. These issues are of the utmost importance since soil-related barriers to natural regeneration and restoration may exist as a result of a very long history of agriculture. This thesis addressed these issues by investigating the soils of abandoned farmland, Cumberland Plain Woodland and restored areas of various ages. In addition to this, the impacts of various patch types (woodland tree, shrub and open, as well as improved perennial pasture) on soil properties and processes, as well as the ground flora were examined. Several soil chemical properties and ecological processes were identified as being of particular importance for the ecology of Cumberland Plain Woodland and its restoration on abandoned farmland. The greatest impact on the soil from past agricultural land use was an increase in the concentration of nitrate, ammonium and total nitrogen within the pasture compared to the woodland patch types, although there was an appreciable amount of site-to-site variability. Despite this, data from two different studies, which were carried out over different spatio-temporal scales, suggest that the abandoned pasture and Cumberland Plain Woodland function differently with respect to the cycling of nitrogen and this may hinder restoration efforts. Doctor of Philosophy (PhD)