Resource Management and Geography - Theses
Permanent URI for this collection
Search Results
1 - 1 of 1
-
ItemA long-term historical perspective on environmental changes in the Wimmera of Western Victoria, Australia( 2016)Salt lakes form a conspicuous element of southern Australian arid and semi-arid regions. The origin and development of these salt lakes is closely tied to major climatic perturbations during the Pleistocene. Unlike most of North America, Europe and much of Asia, Pleistocene climate change in the arid and semi-arid of southern Australia is manifest as a series of aeolian deposits, erosional basins and unique, ancient soils. Sediments that are crucial for palynological studies are largely restricted to the temperate mountainous regions of east and southeast Australia, whereas much of the rest of the continent is remarkably flat and suffers from permanent water deficits or seasonal monsoonal influences. As a consequence, the Quaternary history of Australia has been derived from what are, on a continental scale, atypical climates and landforms. Despite their widespread occurrence, ecological importance and sensitivity to hydro-climatic change, only a handful of Australian palaeoecological studies have utilized the sediments contained within salt lakes. In a continent where any increase in mean annual temperatures will have profound implications for ecological processes and economic activities, it makes sense to try to understand the responses of semi-arid and arid landscapes to recent environmental changes. In addition, land degradation remains a critical and long lasting problem. Overgrazing, land clearance and the development of saline soils are clearly implicated as land degradation processes, especially in southern Australia. As many factors contribute to this pressing socio-ecological problem, it is not sensible to assess this phenomenon without considering its context in terms of long-term processes. In this context, I focus my palaeoecological analysis on a heavily altered landscape located within an area representative of Australian salt lake systems. I aim to disentangle the pre and post European environmental history of this important system and seek to identify, classify and understand land degradation processes, with a focus on plant community changes. This project proceeds by analyzing the history of land use and the ecology of plant communities concentrating on past human burning activities and palaeoenvironmental changes based on evidence from sediments, fossil pollen and microscopic charcoal dating from Aboriginal to European settlement times in the Wimmera of western Victoria, southern Australia. Using fossil pollen and charcoal from lake sediments illustrated that salinity rose substantially as forest diversity decreased since the start of European settlement.