Distribution of logs in a dry sclerophyll forest, Brisbane Ranges, Victoria

Fallen timber is an important habitat resource for small vertebrate and invertebrate animals in forests. This exploratory study investigated the pattern of distribution of fallen timber (here termed 'logs') in a dry sclerophyll forest in the Brisbane Ranges, Victoria, by sampling transects located in
gully, mid-slope and ridge positions, at each of 10 sites. Gullies supported a significantly higher density and volume of logs than ridges. The lowest abundance of logs was on ridges. The mean volume of logs was 98.6 m3/ha for gullies, 38.5 m3/ha at mid-slope positions and 13.1 m3/ha for ridges. The
volume of logs at transects was significantly positively correlated with the density of larger trees (diameter >40 em). A number of animal species in the Brisbane Ranges potentially use logs as a resource for shelter, foraging or perching, and hence the retention ofwoody debris will aid in habitat
management. The uneven distribution of logs in relation to forest topography and the size strueture of trees suggests that gullies, and forest stands with many large trees, are likely to be important habitats for species that use fallen timber. (The Victorian Naturalist 120 (2), 2003, 55-60)

Does application of firefighting foam affect soil invertebrates?

Firefighting foam (Class A foam) is an effective and widespread frrefighting tool often used in environmentally sensitive areas. Although, firefighting foam is known to be ecologically damaging to aquatic invertebrates, application of 1.0% foam to heathland soils showed no detectable impacts on soil invertebrate orders sampled over several months. The results are encouraging for the continued use of Class A foam as a fire suppression technique in areas with high conservation value.

Guadalupian (Middle Permian) brachiopods from Sungai Toh, a Leptodus Shale locality in the Central Belt of Peninsular Malaysia. Part I: Lower Horizons

This work presents a systematic study of Permian Brachiopoda from the Sungai Toh Leptodus Shale locality, Pahang State, Peninsular Malaysia. This locality lies within the Central Belt of Peninsular Malaysia, a tectonic unit characterised.by tuffaceous sediments and limestones of Late Palaeozoic age. Two brachiopod-bearing horizons were studied in detail at this locality, the lower one (Horizon 2) bearing a mixed plant and invertebrate assemblage, including the brachiopods Urushtenoidea chaoi (CHING), Leptodus richthofeni KAYSER, Anidanthus cf. sinosus HUANG, Acosarina dorashamensis (SOKOLSKAJA), A. minuta (ABleH) and unidentifiable species of Linoproduetus, Neochonetes, and Strophalosiina. Horizon 3 contains a more abundant and diverse brachiopod fauna, comprising a total. of 57 species representing 47 genera, including Vediproductus punetatiformis (CHAO), Permianella typica HE & ZHU, Tranrennatia gratiosa (WAAGEN), Leptodus richthofeni KAYSER, Leptodus cf. tenuis (WAAGEN) and "Semibrachythyrina" [= Alphaneospirifer] cf. pyramidiformis LIANG. It is
suggested in this study that the age of the Sungai Toh locality is Capitanian (late Guadalupian) to possibly Wuchiapingian (early Lopingian),
as it appears to correlate well with the Lengwu fauna from Zhejiang in eastern China. The palaeobiogeographical affinities of the Sungai Toh fauna are interesting, mainly indicating strong Palaeo-equatorial affinities, while there are also some elements more typical of the cooler periGondwana
Region.

Drifting or walking? colonisation routes used by different instars and species of lotic, macroinvertebrate filter feeders

Many views of stream invertebrate populations centre on drift as the major route of larval dispersal, but few studies have presented unambiguous information about the role of drift. We present the results from an experiment designed to determine whether the major route of colonisation of substrata by hydropsychid larvae (commonly found in the drift) is by drifting directly onto substrata or by walking along the stream bottom. The experimental design contained four treatments: substrata open to drifters and walkers; fenced substrata open to drifters only; and two treatments open to drifters and walkers that provided forms of fence controls. Fifteen replicates of each treatment were set out at random locations within a riffle at each of three sites, with each site on a different river (the Little River, the Steavenson River and the Acheron River) in the Acheron River catchment. The experiment was run twice, once during autumn (April 1999) and once during early summer (January 2000). Both experiments were colonised by three species of hydropsychids, Asmicridea sp. AV1, and Smicrophylax sp. AV1 and AV2. We found that 2nd/3rd instars of Asmicridea sp. AV1 walked as well as drifted, whereas all others primarily drifted. No relation between numbers of recruits and water speed was found when substrata were open only to drifters, whereas substrata open also to walkers gained more recruits in faster flows. Additionally, larvae more frequently abandoned nets in slow than fast flows, indicating that drifting into unfavourable flow environments may result in mortality or redispersal of larvae. These findings demonstrate that, although drift is important, it is not necessarily the only method used by hydropsychids to colonise substrata. Larvae may have more capacity to choose substrata in fast flows when they colonise substrata by walking. Spot measures of hydropsychid distribution cannot distinguish between these explanations. The finding that walkers can sometimes comprise significant numbers of recruits raises the prospect that hydropsychids can be sourced locally and have not inevitably drifted in from upstream locations.

An experimental examination of colonization as a generator of biotic nestedness

Species assemblages of systems of islands and other fragmented habitats frequently show a "nested-subset" structure in which the biotas of sites with low species richness are non-random subsets of the biotas of richer sites. Much literature suggests that extinction is more likely to produce strongly nested patterns than colonization, although very few experiments have been conducted on the generation of nested-subset patterns. Here, we describe an experiment on nestedness of benthic invertebrates occupying rocks in the littoral zone of a lake in western Victoria, Australia. Data collected from previous work indicated that the invertebrate biotas of rocks were nested. We used initially defaunated, different-sized habitat patches (half house-bricks, full house-bricks, double house-bricks) and followed the time-course of occupation to assess whether nested-subset patterns would emerge, and whether extinction or colonization best accounted for the patterns. We predicted that nestedness would increase through time up to the end of the experiment. This was found to be the case with colonization dominating the establishment of a strongly nested system; extinction appeared to be of relatively little importance over the duration of the experiment. These results suggest that at least in some circumstances, differential colonization may be influential in producing nested-subset patterns but experiments conducted over longer times may be needed to more completely understand the respective roles of extinction and colonization in generating nested-subset patterns in this system.

Sexual conflict and polyspermy under sperm-limited conditions : in situ evidence from field simulations with the free-spawning marine echinoid Evechinus chloroticus

For free‐spawning organisms that release gametes into the sea, sperm limitation (too few sperm to fertilize all eggs) is a major factor limiting reproductive success. Given such circumstances, the presence of several mechanisms to prevent polyspermy (too many sperm) may seem paradoxical; however, a growing body of data suggests that natural fertilization levels, though variable, can routinely be high. Under such conditions, polyspermy is much more likely. The tension between sperm limitation and polyspermy represents sexual conflict because males, in competing to fertilize as many eggs as possible, can impose lethal costs on eggs if multiple sperm gain entry. Here we present data for a marine invertebrate indicating high levels of polyspermy under sperm‐limited conditions. When the sea urchin Evechinus chloroticus was induced to spawn in situ, mean rates of polyspermy were 17.3% ±3.4%, and polyspermy was recorded at rates as high as 62.7%. Polyspermy was nearly always present, even when fertilization rates were <50%, confirming predictions that it should be present under sperm‐limited conditions. Both sperm limitation and polyspermy imposed substantial reproductive costs, and we conclude that both sexual conflict related to polyspermy and sperm limitation have been simultaneous strong selective forces shaping the evolution of reproductive traits in the sea.

Surviving suppression : no detectable impacts of Class A foam on soil invertebrates and some Australian native plants

Firefighting foams (Class A foams) are an effective and widespread firefighting tool which are frequently used in environmentally sensitive areas. Firefighting foams are known to be ecologically damaging in aquatic environments, however their impacts at the plant species or ecosystem level are relatively unknown. Reports of shoot damage to plants, suppressed flowering, and changes in plant community composition suggested that the ecological damage caused by their use may be unacceptable. However, applications of foam to seedlings of some Australian plant species from representative and widespread families, showed no detectable impacts on a range of vegetative growth characteristics. Application of 1.0% foam to heathland soils showed no detectable impacts on soil invertebrate Orders sampled over several months. The results are encouraging for the continued use of Class A foam as a fire suppression technique.

Permian Chonetoidea and Spiriferoidea of Australasia : Gondwanan relationships, provincialism, palaeobiogeography

Members of the Spiriferoidea are dominant in the Permian marine invertebrate faunas of Australia. Genera can be endemic to a particular province, demonstrate a wider Gondwanan and peri-Gondwanan distribution and several indicate a bipolar distribution. Australasian spiriferoids are included within the families Spiriferidae, Neospiriferidae, Trigonotretidae and the Spiriferellidae. Several genera and species are the largest spirferoids ever recorded. Few genera are shared between the Westralian and Austrazean provinces but a higher proportion of genera are shared between the Westralian province and the Cimmerian Realm.
Representatives of the Chonetoidea are a less common but significant element of the faunas. They were used over 20 years ago to define the Westralian and Austrazean provinces of Australasia – concepts that are in widespread use today. The Paratinan and Cimmerian provinces were also defined at that time despite difficulties in their definition. Through more recent studies the Cimmerian Province has been upgraded to a Realm while the Paratinan Province is more clearly defined for the earliest Permian, based on the chonetoids of Patagonia and western and eastern central Argentina.
Distribution of the various genera is best explained by an interplay of factors including surface and deeper oceanic currents, marine water temperatures and tectonic events such as the clockwise rotation of Gondwanan and the dispersal of the peri-Gondwanan Cimmerian terranes. Austrazean faunas developed in isolation under the influence of cooler and cold waters during the early Permian. Late Permian faunas demonstrated more widespread linkages.

The development of biological objectives for streams in a single catchment: a case study on the catchment of western port bay, Victoria, Australia

Government environment protection policies for waterways have traditionally relied on water quality indicators and their objectives. In this paper we describe the development of biological objectives based on invertebrate indicators for inclusion in a government policy for the catchment of Western Port Bay, Victoria. The first step of defining segments (areas with streams in which the same objectives are applied) was problematic, requiring two different approaches, as follows. Site groups initially based on invertebrate community composition derived using multivariate techniques (ordination and classification) proved to be unsuitable for policy segments. Segment boundaries were subsequently defined using topographical (e.g. boundary of foothills and lowland plains), climate (e.g. rainfall) and land-use (e.g. urban) features. We used information and data from reference sites inside as well outside the catchment to derive specific biological objectives based on aquatic invertebrates for these segments. Objectives were specified for the following four indicators – number of invertebrate families, the SIGNAL index, the AUSRIVAS predictive model and the number of key families.

Can sand slugs in rivers deliver conservation benefits? The biodiversity value of tributary junction plug wetlands in the Glenelg River, Australia

Restoration works are carried out to alleviate human impacts and improve habitats within ecosystems. However, human impacts may also create new (anthropogenic) habitat for species to exploit.A dilemma arises when proposed restoration works would remove anthropogenic habitat and the assemblages it supports. Sediment input into the Glenelg River has formed tributary junction plug wetlands at confluences. Sand slug removal is proposed as part of river rehabilitation, but would also drain plug wetlands. We sampled four plug wetland, four river run and three river pool sites to determine whether plug wetlands influence water quality and add to the biodiversity of macroinvertebrates in the Glenelg River.Water quality and macroinvertebrate diversity were similar in plug wetlands, river runs and river pools.Assemblages were distinct among all sites, regardless of type, so there was no characteristic ‘plug-wetland fauna’. Therefore, although removal of plug wetlands would not cause a dramatic loss of invertebrate biodiversity, it would destroy anthropogenic habitat that supports a similar range of species to natural habitats in a river subject to multiple degrading processes. Gains from rehabilitation should be weighed against the value of anthropogenic habitat and the extent of similar habitat lost elsewhere in the ecosystem.

Effect of Phytophthora cinnamomi on the habitat utilization of Antechinus stuartii in a Victorian forest

Phytophthora cinnamomi (Cinnamon fungus) is a pathogenic soil fungus which infects plant communities along the south-eastern coast of Australia, and the south-western corner of Western Australia. The symptoms of this disease include chlorosis, death of branches (ie. ‘dieback’), retarded growth and the eventual death of infected plants. This leads to devastating effects upon plant communities by altering both the structural and floristic characteristics of these communities. Small mammal species are dependent on specific features of their habitat such as vegetation structure and floristics. This thesis investigated alterations to the habitat of the insectivorous marsupial mouse, Antechinus stuartii, due to the presence of P. cinnamomi. The study was undertaken in an area of an open forest in the Brisbane Ranges, Victoria. Significant changes were found in both the floristic composition and structure of the vegetation at study sites infected with P, cinnamomi, compared to uninfected sites. The habitat utilization by A. stuartii of uninfected and infected vegetation was investigated using live trapping and radio-telemetric techniques. Capture rates were higher at sites uninfected by P. cinnamomi, and both male and females selected areas free from infection. Home range areas of males were significantly larger than those of females as assessed by telemetry. Both sexes spent a high proportion of time in areas dominated by Xanthorrhoea australis (Austral grass tree). There were significant relationships between the abundance of A. stuartii and the denseness of vegetation above 1 metre in height, and in particular, the proportion of cover afforded by X. australis. There were no significant differences in the cover of Eucalyptus spp. between uninfected and infected sites, but there were significantly more nest hollows in infected areas. The abundance of invertebrates was examined using pitfall traps. There were no significant differences in the abundance of the larger invertebrate taxa at infected and uninfected sites, but higher abundances of some micro-invertebrate groups in infected areas were recorded. The most likely factors considered to be influential in the habitat selection of A. stuartii were vegetation structure, and the presence of X. australis. To assess whether these factors were important the leaves of X. australis were removed with a brushcutter, to mimic the early effects of infection with P. cinnamomi. Animals did not respond to the alteration of vegetation structure in the short term (3-4 days). Longer-term experiments are required to assess the habitat utilization of A. stuartii at different periods following habitat manipulation. The implications of the presence of P. cinnamomi on the conservation of fauna are discussed. The destructive nature of the pathogen, and the slow rate of recovery from the disease, means that P. cinnamomi can be considered a threatening process to plant communities and the fauna that reside within that habitat. Future management of this disease within natural areas must therefore be cognisant of the potential of P. cinnamomi to significantly affect faunal as well as vegetative communities.

Evaluation of the effectiveness of marine protected areas in temperate waters of Australasia

An evaluation of the effectiveness of Marine Protected Areas (MPAs) in temperate waters of Australasia has been conducted for this thesis. The aim was to identify key elements needed in a strategy for establishment and management of MPA’s in temperate waters of Australasia. This aim was achieved by assessing how effective a sample of MPA’s has been in meeting the conservation objectives for their establishment and by identifying factors that have contributed to success or failure of the MPA’s in meeting these objectives. Particular attention was paid to the objectives of ecological sustainability and biodiversity preservation. A MPA for the purposes of this research was defined as an area of coastal or marine environment, with a substantial subtidal component, set aside by law primarily for conservation purposes. The study region encompassed the coastal zones of Victoria, Tasmania and South Australia (Australia) and New Zealand. The questions posed in order to address the aim of this thesis were; a) Have existing MPA’s been effective in achieving conservation objectives? b) What have been the important influences on effectiveness of existing MPA’s? c) What are the key elements required for implementation of effective MPA’s? The thesis is divided into three parts. Part I is a review of the literature on implementation and effectiveness of MPA’s. Part II presents a detailed evaluation of one MPA: Point Lonsdale Marine Reserve (PLMR), Victoria, Australia. Part in is an evaluation of a number of Australasian temperate MPA’s based on information provided in a survey of people involved in management of MPA’s, and from a variety of published and unpublished documents. The MPA’s are described, evidence about ecological effectiveness is presented and factors that have enhanced and limited the ability of these MPA’s to achieve conservation objectives are derived. A substantial amount of scientific evidence was found for increases in abundance, mean size and size range of fish and invertebrate populations within the boundaries of ‘no-take’ MPA’s, Some evidence was found for ‘spillover’ of adults and juveniles into adjacent fishing grounds. Ecological effects detected within ‘no-take’ MPA’s in Australasia matched those described in the literature. The abundance and mean size of a number of previously exploited species have increased, migration into adjacent fishing grounds has been documented, and species richness has increased in at least one MPA. The PLMR was established primarily to protect the scientifically significant intertidal rock platforms. The results of the case study suggest that this objective has been achieved. Opinions about effectiveness were obtained for 28 MPA’s. Of these 19 were considered to be achieving some objectives and 10 were considered to be performing well in terms of overall ecological effectiveness. Positive effects on biodiversity were generally assumed as a result of reduction of damaging anthropogenic effects on habitat. Many questionnaire respondents noted an increase in community awareness about and support for marine conservation as a result of proclamation of MPA’s, Overall, the results support the value of MPA’s for sustainability of fish stocks and preservation of biodiversity, but there is substantial doubt over whether some of the MPA’s are too small to maintain benefits in the long-term. ‘No-take’ MPA’s, particularly those more remote from the impacts of human activities, have been the most effective in achieving objectives. A number of interacting factors important to eventual success of MPA’s were identified. The most important enhancing factors identified for the PLMR were physical attributes that limit the extent of human use and a strong conservation ethic amongst many of the visitors to this marine reserve. Limiting factors were far more numerous. Of most concern is the inadequacy of at-site management. Almost half of visitors to the area were not aware of its marine reserve status, despite the fact many were frequent visitors. The need for better educational and interpretative material on-site is highlighted by the results of the PLMR visitor survey. A total of 56 factors that have enhanced effectiveness and 46 factors that have limited effectiveness of Australasian temperate MPA’s were identified. A number of factors were important in more than one MPA and this was used to derive a set of critical, or key, factors. For example, a conclusion of all three approaches used in this study is that failure to implement day-to-day management through lack of resources was a major constraint on effectiveness. The importance of MPA’s to marine conservation depends, in part, on how well they are managed. The key factors that influence MPA effectiveness were used as the basis for derivation of the main requirements for implementation of MPA’s that will be capable of meeting the objectives for their establishment. The most important needs are: • that ‘no-take’ areas surrounded by buffer zones form the basis for a system of MPA’s; • that a high level of protection is bestowed by legislation and regulations; • that a minimum size be set for the ‘no-take’ core areas; • that the selection of sites for MPA’s takes into account land-based impacts; • that institutional arrangements are developed specifically for MPA’s; • that funding for MPA’s is increased to enable effective management; • that day-to-day management is implemented in all MPA’s, with enforcement and education programs as priority areas; • that a monitoring program for one or more MPA in each 'State' is established to provide evidence of ecological effects of reservation; • that public and stakeholder involvement in development and implementation of MPA’s is encouraged as this will influence the degree of public support and compliance; • that community-based programs to educate the general public, stakeholders, the media and decision-makers about the value of MPA’s are essential; and • that measures to reduce financial impact on affected stakeholders be implemented.

Breeding behaviour and ecology of the sexually size-dimorphic brown songlark, Cinclorhamphus cruralis

The Australian endemic brown songlark, Cinclorhamphus cruralis, is one of the most sexually size-dimorphic of all birds, and yet its breeding ecology remains poorly documented. Here we redress this situation by describing the breeding activities of brown songlarks over three years (1998–2000) in the semi-arid grasslands of south-western New South Wales. Study populations of this nomadic species were selected in late August of each year on the basis of high adult abundance. Adult males at these sites were, on average, 2.3 times heavier than females. Over the three seasons, nesting activities started in early to late August and continued until early November or December. Males were highly polygynous and, on average, occupied territories of about 4.0 ha. Nests were well concealed at the base of small shrubs and grass tussocks or in thick herbage. Clutches ranged in size from 2 to 5 eggs (mean 3.2) and were incubated exclusively by the female for 11–13 days (mean 12.1). Nestlings received a range of invertebrate prey, mainly from the female, for 10–14 days (mean 11.5) before leaving the nest. Only 17% of nesting attempts were estimated to be successful, and each of these nests produced an average of 2.7 fledglings. Predators, including foxes, Vulpes vulpes, and brown snakes, Pseudonaja textilis, were the main cause of nest failure. Some females produced replacement clutches following nest failure, while others laid second clutches after the success of an earlier brood. We speculate that extreme size dimorphism has evolved in this species because (i) males compete physically for breeding territories, and (ii) habitat heterogeneity and excellent visibility of their surroundings allow some males to defend territories of sufficient size to support nesting by multiple females

Resource heterogeneity for stream detritivores

Invertebrate animals in headwater streams depend upon leaves, wood and bark for both food and living space. This project demonstrated the strength of that dependence where the patchiness in habitat is influenced at the smallest spatial scales by the movement of sediments, and at the largest by agricultural clearing.

Water regime and salinity changes in wetland macroinvertebrate communities

The research successfully showed how biological communities change in wetlands that are affected by salinity and altered water regimes as a result of irrigation and river regulation. As an outcome of the study, recommendations have been made for the future management of wetlands in the Kerang region in northern Victoria.