Bronwyn Price

Mapping forest patches and scattered trees from SPOT images and testing their ecological importance for woodland birds in a fragmented agricultural landscape

Scattered trees represent an important element within the agricultural matrix for birds. The aims of this study were to develop methods for mapping isolated trees from satellite imagery and to assess the importance of isolated trees for bird species richness. Field sampling of birds and plants was conducted at 120 sites in south-east Australia. We mapped tree cover from Landsat and SPOT images using a combination of spectral and segmentation based methods. Mapping of isolated trees as point objects was highly accurate (80–90%). Tree cover at spatial extents of 3–28 ha around sites explained 60% of the variability in woodland–dependent bird species richness. However, isolated trees in agricultural areas made just a small contribution to explaining the spatial variability in overall avian richness. This approach can be used for more extensive assessment of avian habitat quality from high spatial resolution images across a range of human modified landscapes.

Disentangling How Landscape Spatial and Temporal Heterogeneity Affects Savanna Birds

In highly seasonal tropical environments, temporal changes in habitat and resources are a significant determinant of the spatial distribution of species. This study disentangles the effects of spatial and mid to long-term temporal heterogeneity in habitat on the diversity and abundance of savanna birds by testing four competing conceptual models of varying complexity. Focussing on sites in northeast Australia over a 20 year time period, we used ground cover and foliage projected cover surfaces derived from a time series of Landsat Thematic Mapper imagery, rainfall data and site-level vegetation surveys to derive measures of habitat structure at local (1–100 ha) and landscape (100–1000s ha) scales. We used generalised linear models and an information theoretic approach to test the independent effects of spatial and temporal influences on savanna bird diversity and the abundance of eight species with different life-history behaviours. Of four competing models defining influences on assemblages of savanna birds, the most parsimonious included temporal and spatial variability in vegetation cover and site-scale vegetation structure, suggesting savanna bird species respond to spatial and temporal habitat heterogeneity at both the broader landscape scale and at the fine-scale. The relative weight, strength and direction of the explanatory variables changed with each of the eight species, reflecting their different ecology and behavioural traits. This study demonstrates that variations in the spatial pattern of savanna vegetation over periods of 10 to 20 years at the local and landscape scale strongly affect bird diversity and abundance. Thus, it is essential to monitor and manage both spatial and temporal variability in avian habitat to achieve long-term biodiversity outcomes.

MODIS time series as a tool for monitoring fires and their effects on savanna bird diversity

In this study, we aimed to explore the effect of fires on bird diversity in Australia’s tropical savannas. Bird surveys were conducted at 69 sites between 2005 and 2007 to estimate bird species richness and abundance within the Mornington Sanctuary, the Kimberley, north-west Australia. We used MODIS (Moderate Resolution Imaging Spectroradiometer) and Landsat satellite imagery to map fire scars and to quantify vegetation cover parameters, and QuickBird imagery to map the percentage tree cover. Bird species richness and abundance were higher in areas exhibiting minimum seasonal and interannual changes, e.g. in riparian areas, near water and where tree cover was high. We found a significant negative effect of fire on bird diversity following the extensive late dry-season fires of 2006. These findings support the view that intense and large fires are threatening biodiversity and reinforce the importance of reducing the occurrence of late dry-season fires, which are the most severe and extensive. MODIS satellite imagery was found to provide a cost-effective approach to monitoring savanna landscapes, assessing the state of vegetation and monitoring fire dynamics.

Teaching Effective Literature Use Skills for Research Reports in Geography

The ability to use literature effectively is essential to provide context and interpret results for any research project. Undergraduate students in geographical disciplines are regularly required to produce research reports, yet formal training in effective literature use is minimal. In this study students were taught effective literature use methods in a workshop involving group work and class discussion. Comparison was made between current students’ and previous students’ performance to determine any improvement with the new teaching methods. Results demonstrate that a relatively basic approach of explicitly teaching effective literature use can be effective and improve students’ research report writing skills.

Real-time 4D visualization of migratory insect dynamics within an integrated spatiotemporal system

This paper presents a new approach of spatiotemporally visualizing the simulation output of migratory insect dynamics and resultant vegetation changes in real-time. The visualization is capable of displaying simulated ecological phenomena in an intuitive manner, which allows research results to be easily understood by a wide range of users. In order to design a fast and efficient visualization technique, a simplified mathematical model is applied to intelligibly represent migrating groups of insects. In addition, impostors are used to accelerate rendering processes. The presented visualization method is implemented in an integrated spatiotemporal analysis system, which models, simulates and analyzes ecological phenomena such as insect migration through time at a variety of spatial resolutions.