Fish use of flooded margins of an intermittently open estuary

Fish communities in the shallow flooded margins of an intermittently open estuary were examined over an 18 month period. A distinct shift in the fish assemblage occurred when the mouth of the estuary closed and was associated with changes in the hydro-period, food availability and physico-chemical changes in the main channel.

Hydro-acoustic remote sensing of benthic biological communities on the shallow South East Australian continental shelf

Information regarding the composition and extent of benthic habitats on the South East Australian continental shelf is limited. In this habitat mapping study, multibeam echosounder (MBES) data are integrated with precisely geo-referenced video ground-truth data to quantify benthic biotic communities at Cape Nelson, Victoria, Australia. Using an automated decision tree classification approach, 5 representative biotic groups defined from video analysis were related to hydro-acoustically derived variables in the Cape Nelson survey area. Using a combination of multibeam bathymetry, backscatter and derivative products produced highest overall accuracy (87%) and kappa statistic (0.83). This study demonstrates that decision tree classifiers are capable of integrating variable data types for mapping distributions of benthic biological assemblages, which are important in maintaining biodiversity and other system services in the marine environment.

Coastal marine habitat mapping using multi-beam acoustics, video data and a decision tree classifier on the temperate south-east Australian continental shelf

In this habitat mapping study, multi-beam acoustic data are integrated with extensive, precisely geo-referenced video validation data in a GIS environment to classify benthic substrates and biota at a 33km2 site in the near shore waters of Victoria, Australia. Using an automated decision-tree classification method, 5 representative biotic groups were identified in the Cape Nelson survey area using a combination of multi-beam bathymetry, backscatter and derivative products. Rigorous error assessment of derived, classified maps produced high overall accuracies (>85%) for all mapping products. In addition, a discrete multivariate analysis technique (kappa analysis) was used to assess classification accuracy. High-resolution (2.5m cell-size) representation of sea floor morphology and textural characteristics provided by multi-beam bathymetry and backscatter datasets, allowed the interpretation of benthic substrates of the Cape Nelson site and the communities of sessile organisms that populate them. Non-parametric multivariate statistical analysis (ANOSIM) revealed a significant difference in biotic composition between depth strata, and between substrate types. Incorporated with other descriptive measures, these results indicate that depth and substrate are important factors in the distributional ecology of the biotic communities at the Cape Nelson study site. BIOENV analysis indicates that derivatives of both multi-beam datasets (bathymetry and backscatter) are correlated with distribution and density of biotic communities. Results from this study provide new tools for research and management of the coastal zone.

Vascular plant and small mammal communities over an elevational gradient

Plant species richness and plant and small mammal beta diversity decline over the elevational gradient in the Otway ranges. These patterns are influenced by climate, habitat and spatial structure. This highlights the need to preserve continuous habitat and understand the influence of climate, to conserve communities in the changing future.

Distribution, ecology and conservation of small mammals in fire-prone landscapes

Management of fire for biodiversity conservation is a global issue. This research provides new insights into the distribution of mammals in fire-prone eco-systems. A key outcome of this thesis is that understanding the role of fire over broad spatial scales and long time periods will benefit ecological and conservation management.

Internal structure and paleoecology of the lower Permian Uzunbulak reef complex of the Tarim Basin, Northwest China

The internal construction and biotic communities of the Uzunbulak reef of the northwestern Tarim Basin are studied for the first time. The reef was built during the Sakmarian, while the reef substrate and capping beds are of latest Asselian and earliest Artinskian ages, respectively. The reef substrate beds are composed of skeletal and oncoid grainstone. Those fusulinid-dominated skeletal shoals and oncoid banks indicate a high-energy environment and produced local topographic highs on which the reef grew. Reef framework consists mainly of calcisponge bafflestone, calcisponge-Thartharella framestone, and Tubiphytes, Archaeolithoporella and Girvanella boundstones. Calcisponges were the primary frameconstructors that baffled high-energy currents. Archaeolithoporella, Tubiphytes, Girvanella and possibly microbes acted as the primary binders for the boundstone framework. Fusulinids and brachiopods were common reef dwellers. The interreef facies sediments are composed of skeletal-crinoid wackestone-packstone. Most of bioclasts have thick, micritized envelopes. The back-reef facies deposits consist of alternating skeletal packstone to wackestone and black shale. Sea-level fluctuations were probably accountable for the reef growth and demise.

Of the reefal dwellers, brachiopods are extraordinarily abundant in Uzunbulak. They are assignable to five distinctive associations, one each from the reef substrate, framework and inter-reef facies, respectively, and two from the reef capping facies. The brachiopods in the substrate beds were mostly attached to hard substrates by a pedicle, while a few species rested on soft substrates by support of halteroid spines. Cementation of the ventral valve on hard substrates characterizes attachment of the reef framework brachiopods. All inter-reef species were anchored into the substratum comprising hard material by a strong pedicle. Back-reef brachiopods dominantly rested on the soft substrates by support of halteroid spines. the framework brachiopods had the strongest wave-resistant capability;those from both substrate and inter-reef facies were moderately capable of withstanding agitation; and the backreef species preferred to live in calmwater, organic-rich muddy environments.

Ecology and conservation of ground-foraging birds of temperate woodlands

Many ground-foraging birds are in serious decline. This research examined the distribution of these birds and revealed that they were most common in native pine woodlands of which little remains due to past clearing. The foraging habitat requirements of 13 species were documented providing valuable information for their conservation.

Hydrodynamics, nutrients and algae of Fitzroy and Merri River estuaries

Various physical, biological and chemical attributes were investigated for the Fitzroy and Merri River estuaries. This research found algal communities were most influenced by high nitrogen concentrations at times of low flow. Mangement of nutrients within each catchment is therefore of high importance to reduce the possibility of future blooms.

Landscape properties mediate the homogenization of bird assemblages during climatic extremes

Extreme weather events, such as drought, have marked impacts on biotic communities. In many regions, a predicted increase in occurrence of such events will be imposed on landscapes already heavily modified by human land use. There is an urgency, therefore, to understand the way in which the effects of such events may be exacerbated, or moderated, by different patterns of landscape change. We used empirical data on woodlanddependent birds in southeast Australia, collected during and after a severe drought, to document temporal change in the composition of bird assemblages in 24 landscapes (each 100 km2) representing a gradient in the cover of native wooded vegetation (from 60% to <2%). We examined (a) whether drought caused region-wide homogenization of the composition of landscape bird assemblages, and (b) whether landscape properties influenced the way assemblages changed in response to drought. To quantify change, we used pairwise indices of assemblage dissimilarity, partitioned into components that represented change in the richness of assemblages and change in the identity of constituent species (turnover). There was widespread loss of woodland birds in response to drought, with only partial recovery following drought-breaking rains. Region-wide, the composition of landscape assemblages became more different over time, primarily caused by turnover-related differentiation. The response of bird assemblages to drought varied between landscapes and was strongly associated with landscape properties. The extent of wooded vegetation had the greatest influence on assemblage change: landscapes with more native vegetation had more stable bird assemblages over time. However, for the component processes of richness- and turnoverrelated compositional change, measures of landscape productivity had a stronger effect. For example, landscapes with more riparian vegetation maintained more stable assemblages in terms of richness. These results emphasize the importance of the total extent of native vegetation, both overall cover and that occurring in productive parts of the landscape, for maintaining bird communities whose composition is resistant to severe drought. While extreme climatic events cannot be prevented, their effects can be ameliorated by managing the pattern of native vegetation in anthropogenic landscapes, with associated benefits for maintaining ecological processes and human well-being.

Governance in rural communities: the case of Victoria

State and federal government policies for rural areas have encouraged local people and organizations to play a greater role in the provision of their local services. This emphasis on local participation has been described as a shift from ‘government’ to ‘governance’. However while there is an emerging research around small towns in Australia there is very little known about the processes of community governance. This paper focuses on local development groups in small towns in rural Victoria that have emerged or have been reconstituted with a broader community focus following municipal amalgamations. The basic aim of this paper is analyse to what degree these local community development groups can be regarded as constituting a form of community governance and the implications this has for democracy and accountability in small rural areas. The paper begins with a discussion of community governance as it represented in the literature. We then analyse ten case studies from across Victoria in the light of the changing political context.

Observations of the ecological impacts of Sambar Cervus unicolor in East Gippsland, Victoria, with reference to destruction of rainforest communities

Damage caused by Sambar, particularly browsing, antler rubbing and physical removal of particular plant species, is resulting in serious ecological consequences. Threatening processes instigated or maintained by Sambar include: loss of individual taxa, altered vegetation structure and massive
widespread removal and prevention of regeneration, which is now resulting in the loss of plant communities in some areas. These observations are particularly disturbing, as it is apparent that Sambar are yet to reach their full ecological and population potential in south-eastern Australia. The destruction documented ill this article is now so widespread and so severe that in places it represents an ecological disaster for specific plant and animal species, ecological vegetation classes and floristic communities. We strongly recommend that Sambar in particular, and feral deer in general. should no longer be protected under the Wildlife Act 1975 so that control methods can be devised and implemented. It now appears that such measures will he essential for the long-term survival of some fragile plant species and communities in Victoria. (Title: Victorian Naturalist 122(4) 2005, 189-200

Impact of stresses imposed on macroinvertebrate communities in two suburban streams

The aim of the project was to determine factors which explain the distribution of macroinvertebrates in two Melbourne streams both drastically affected by urbanisation. A detailed description is given of Dandenong Creek, flowing through the south-eastern suburbs, and Darebin Creek, in the northern suburbs, emphasising stream features likely, or known, to influence the drift and benthic fauna. Faunal sampling was carried out in Dandenong Creek from June 1992 until July 1993, and in Darebin Creek from February 1995 until March 1998. Physicochemical parameters were also recorded. The collected data, together with previously existing data, were analysed using multivariate analyses: non-metric multi-dimensional scaling (NMDS); analysis of similarities (ANOSIM); matching biotic and abiotic variables using BIOENV, and principal component analysis (PCA). Various biotic and diversity indices were calculated in an attempt to identify the major factors responsible for the failure of the fauna to recover from previously more seriously degraded water quality. The contribution of drift to the colonisation potential in Dandenong Creek appeared to be impacted by retarding basins, underground barrel-draining and channelization. Results also indicated that increased conductivity adversely affected the fauna in the lower reaches of Dandenong Creek. It was concluded that in Darebin Creek, high nutrient levels, as well as other pollutants, had resulted in low macroinvertebrate diversity in both the drift and benthos. If, as this study suggests, faunal diversity is a valid measure of stream health, the following factors need to be addressed for catchment-wide, stream management: lack of riparian zone vegetation (increasing bank erosion and making the benthic habitat unstable, with greater temperature variability); control of stormwater runoff (flow variability, increased conductivity, nutrient levels, sediment loads, sewage effluent, industrial discharges and heavy metals), and to modify retarding basins to increase stream continuity.