Honours supervisors and projects

Prof. Ralph Mac Nally

Landscape Eclogy

Phone: 9905 5642
E-mail: ralph.macnally@sci.monash.edu.au

Research interests

Biodiversity: Habitat fragmentation and habitat loss

Natural habitats are much reduced and incised on all continents, apart from Antarctica, by human actions. What effects do these activities have on biodiversity? Is the loss of habitat more critical than its subdivision? Can we predict the kinds of species that are most at risk of extinction based on their biological characteristics (e.g. mobility, population densities)? Are some kinds of animals more prone to problems than others (e.g. birds vs mammals)?

Biodiversity: Habitat degradation

In a short time, Europeans have massively altered the Australian continent offering opportunities to invaders and adversely affecting endemic species. The kinds of habitat change are many, but alteration of forests have been pervasive. Forests have been stripped of their ‘old growth’ areas, with few large, old trees remaining. These trees have been shown to be critical for many animals, especially as they provide a number of important resources: hollows and fallen timber, when limbs drop and very old trees die. What are the effects on biodiversity of widespread removal of large, old trees? What are the impacts of the widespread removal of fallen timber for firewood, and the prevention of trees from reaching advanced old ages?

Biodiversity: Landscape reconstruction

Most effects of human-induced landscape and habitat change are negative, reducing the capacity of many native species of animals and plants from persisting. Gradually, there is a growing awareness through obvious, widespread declines in land and landscape ‘quality’ (e.g. salinization, loss of birds and mammals) that landscapes must be revegetated to address these problems. While much revegetation has been done to address hydrological issues, can landscapes also be ‘reconstructed’ to better address ecological dysfunction such as loss of species, reduced productivity and impaired fluxes? Some natural vegetation types have been disproportionately reduced (e.g. buloke woodlands in western Victoria), placing especially severe strains on species within those landscapes that depend on those types of habitat. Can preferential replantings of badly affected vegetation communities be conducted? What are the social and economic impediments to enacting these objectives and how can they be addressed?

Biodiversity: Community ecology of birds

Many of the ideas attempting to explain why the observed numbers and kinds of species occurring in any given habitat have originated in the Northern Hemisphere. But, given the climatic instability of most of Australia, these ideas on coexistence and diversity do not seem especially relevant to this continent. How can we account for ‘community structure’ in such spatially and temporally dynamic assemblages? Are there any consistent patterns comparable to those seen in other parts of the world? What kinds of specific theories are needed to understand the nature of Australian bird communities? What limitations and constraints do Australian observations place on general community theory?

Understanding ecological information

The revolutionary recognition that ecological information is very dependent on how it is collected and measured has thrown many concepts of community and population ecology into disarray. For example, many previously ‘compelling’ experiments now are believed to be potentially artefactual because the scales were just incorrect for addressing these issues. How can ecological information be made less contingent on scales of observation or measurement? Is this possible at all? How are the results of ecological experiment dependent on arbitrary choices of spatial and temporal scale?

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