The relative importance of landscape properties for woodland birds in agricultural environments

1. Studies of landscape change are seldom conducted at scales commensurate with the processes they purport to investigate. Landscape change is a landscape-level process, yet most studies focus on patches. Even when landscape context is considered, inference remains at the patch-level. The unit of investigation must be extended beyond individual patches to whole mosaics in order to advance understanding of faunal responses to landscape change.

2. In this study, we aggregated data from multiple sites per landscape such that both the response and explanatory variables characterized 'whole' landscapes, allowing for landscape-level inference about factors influencing species' incidence.

3. We used hierarchical partitioning and Bayesian variable selection methods to develop species-specific models that examined the influence of four categories of landscape properties – habitat extent, habitat configuration, landscape composition and geographical location – on the incidence of 58 species of woodland-dependent birds in 24 agricultural landscapes (each 100 km2) in south-eastern Australia.

4. There was strong evidence for a positive effect of habitat extent for 27 species. Thirty species were related to at least one of the four landscape composition variables, and geographical location was important for 19 species. Habitat configuration was influential for 13 species and where important, the impacts of fragmentation per se were detrimental.

5. Variation among species in the influential landscape variables indicates that different species respond to different sets of cues in land mosaics. Thus, although all species were grouped a priori as 'woodland-dependent', expectations based on general ecological characteristics may prove unreliable.

6. Synthesis and applications. These results underscore the value of moving beyond the fragmentation paradigm focused on the spatial pattern of habitat vs. non-habitat, to a greater appreciation of the composition and heterogeneity of land mosaics. Landscape-level inference will enable improved conservation outcomes by recognizing the influence of landscape properties on biota and devising strategies at this scale to complement patch-based management. We provide strong empirical evidence that biodiversity management in agricultural landscapes must focus on habitat extent. Complementary management of other landscape attributes, such as habitat aggregation and intensity of agricultural land-use, will also enhance the value of agricultural landscapes for woodland birds.

Bayesian clustering with AutoClass explicitly recognises uncertainties in landscape classification

Clustering of multivariate data is a commonly used technique in ecology, and many approaches to clustering are available. The results from a clustering algorithm are uncertain, but few clustering approaches explicitly acknowledge this uncertainty. One exception is Bayesian mixture modelling, which treats all results probabilistically, and allows comparison of multiple plausible classifications of the same data set. We used this method, implemented in the AutoClass program, to classify catchments (watersheds) in the Murray Darling Basin (MDB), Australia, based on their physiographic characteristics (e.g. slope, rainfall, lithology). The most likely classification found nine classes of catchments. Members of each class were aggregated geographically within the MDB. Rainfall and slope were the two most important variables that defined classes. The second-most likely classification was very similar to the first, but had one fewer class. Increasing the nominal uncertainty of continuous data resulted in a most likely classification with five classes, which were again aggregated geographically. Membership probabilities suggested that a small number of cases could be members of either of two classes. Such cases were located on the edges of groups of catchments that belonged to one class, with a group belonging to the second-most likely class adjacent. A comparison of the Bayesian approach to a distance-based deterministic method showed that the Bayesian mixture model produced solutions that were more spatially cohesive and intuitively appealing. The probabilistic presentation of results from the Bayesian classification allows richer interpretation, including decisions on how to treat cases that are intermediate between two or more classes, and whether to consider more than one classification. The explicit consideration and presentation of uncertainty makes this approach useful for ecological investigations, where both data and expectations are often highly uncertain.

Occurrence of small mammals in a fragmented landscape: the role of vegetation heterogeneity

Most studies of habitat use by small mammals rely on data from trapping grids. Such studies pertain to habitat use by individuals, which may not reflect population-level requirements. To meet the challenge of landscape change, it is important to understand habitat use by populations across large geographic areas. We surveyed small mammals in 48 forest remnants across a 300 km2 study area, to investigate the influence of vegetation heterogeneity on regional distributions. Information-theoretic techniques were used to evaluate models of vegetation associations. Richness of native mammals was influenced by vegetation condition: disturbed sites supported fewer species. Models for individual species showed the agile antechinus, Antechinus agilis, to prefer structurally diverse forest vegetation, the long-nosed potoroo, Potorous tridactylus, to favour mesic shrub communities, the bush rat, Rattus fuscipes, to prefer complex low cover regardless of composition, the swamp rat, Rattus lutreolus, to favour reduced canopy cover, and the house mouse, Mus domesticus, to prefer disturbed vegetation. To satisfy the needs of all native species, a mosaic of natural vegetation is required. Degradation and simplification of forest vegetation have detrimental consequences. These results highlight the need to consider habitat quality, together with more traditional biogeographic variables, when investigating factors influencing patch occupancy by native fauna in modified landscapes.

Therapeutic Discourse and the American Public Philosophy: On American Liberalism's Troubled Relationship with Psychology

I explore the main currents of postwar American liberalism. One, sociological, emerged in response to the danger of mass movements. Articulated primarily by political sociologists and psychologists and ascendant from the mid-fifties till the mid-seventies, it heralded the "end of ideology." It emphasized stability, elitism, positive science and pluralism; it recast normatively sound politics as logrolling and hard bargaining. I argue that these normative features, attractive when considered in isolation, taken together led to a vicious ad hominem style in accounting for views outside the postwar consensus. It used pseudo-scientific literature in labeling populists, Progressives, Taft conservatives, Goldwaterites, the New Left and others "pathological," viz. mentally ill. Hence, "therapeutic discourse." I argue that philosophical liberalism, which reasserts the role of political theory in working out norms and adjudicating disagreement, is a more profitable way of thinking about and defending from critics liberalism. I take the philosopher John Rawls as the tradition's modern representative. This inquiry is important because the themes of sociological liberalism are making a comeback in American public discourse, and with them perhaps the baggage of therapeutic discourse. I present a cautionary tale.

Sculptural abstraction of landscape

The purpose of my Senior Scholar project was to create a series of sculptures that are based on the interaction of natural forms within a selected landscape setting. I hope to convey a sense of how I view and interpret the landscape and to create works that stimulate a sense of wonder in the mind of the viewer. This fascination, perhaps even obsession, with the power of the landscape has kept me going throughout the year. As a source of ideas and imagery, the landscape can never be depleted. There will always be new combinations of landscape elements, different light conditions, and changing seasons to provide me with fresh ideas. Research for the project took me to many different places, be it my trip to Monhegan Island or driving to New York City to study the cityscape. I began the year working in steel and plaster, combining the two in works that explore the interaction between living tree roots and inanimate rocks. This led to a series entitled Landscape Recollections, comprised of welded steel forms housed in protective wooden boxes and lit from inside. After visiting New York City, architecture began to playa role in my work, as seen in the two Roadcut pieces and the Cathedral Woods series. Roadcut #1 and Roadcut #2 explore the relationship between a man-made road and the landscape that lies beneath and around it. The Cathedral Woods pieces incorporate architecture in a more abstract manner, using imagery derived from Gothic cathedrals to convey a sense of quiet peacefulness. The soaring verticality of Gothic architecture integrates with the tall tree forms in each piece, enabling me to intertwine these two elements into one another and create a harmonious relationship between architecture and nature. Throughout the year I have kept a sketchbook in which I draw from life, jot down ideas, and take notes on how the project is progressing. I have also completed several large charcoal drawings of my sculptures in which I explore different ways of viewing the steel forms. I am grateful to have had the opportunity to undertake this project, as it has been a very difficult but rewarding process of observing, interpreting, and manifesting the landscape according to my personal vision and experiences.

Contemporary philosophy and J.L. Shaw

Commemorative volume on Jaysankar Lal Shaw, b. 1939, Indian philosopher.

In dialogue with A.D. Hope: dialogue one: childhood and adolescence

[Alec Derwent Hope, born in Cooma 1907, won a scholarship to University College, Oxford, after majoring in English and Philosophy at Sydney University, and returned to a life of teaching and writing from the ‘thirties. His pre-eminence in literary culture was underpinned by his appointment as Professor of English at University College, Canberra, the forerunner of the Australian National University. His work in poetry, translations, and criticism provoked intense response, never indifference. His first published volumes were the satirical sequence, Dunciad Minimus : An Heroic Poem (1950), and selection of poems, The Wandering Islands (1955); amongst the final volumes were the autobiographical Chance Encounters (1992) and Selected Poems (1992).
Dialogue One was designed to explore what connections can be made between the life of the child and the values engendered in this formative phase and the adult’s creative work and view of the world; an exploration shaped by what might be seen as a relentless irony inherent in his poetry and his other scholarly productions and by Hope’s view that childhood is a place of the sacred and of secrets that are best protected from the limiting force of definition--somehow best kept suspended between the unconscious and the conscious mind to draw from when enacting a poetic vision of life. To that extent, Dialogue One is an attempt to navigate territory that might be seen as Hope’s mindscape and landscape as it emerged in childhood and adolescence.
The following exchange comprises selected excerpts from the transcripts of Ann McCulloch’s videoed interviews in Melbourne 1988, The Dance of Language: The Life and Work of A.D. Hope, as well as from her many conversations with Hope between 1981 and 1996 in Canberra.]