Academic literature on the topic 'Otway ranges'

The Australian genus Theprisa Moore, 1963, is taxonomically revised to comprise five species, two newly described: Theprisa darlingtoni Liebherr & Porch, sp. nov. of Tasmania, and Theprisa otway Liebherr, Porch & Maddison, sp. nov. from the Otway Ranges, Victoria. Two previously described species, T. australis (Castelnau) and T. montana (Castelnau), are distributed in the mountains of Victoria. The third previously described species, T. convexa (Sloane) is found in Tasmania. A lectotype is designated for T. convexa because the various syntypes are ambiguously labelled. Cladistic analysis based on morphological characters establishes monophyly of Theprisa relative to the Australian genera Sitaphe Moore and Spherita Liebherr. This and a second clade of Australian genera (Pterogmus Sloane, Thayerella Baehr, and Neonomius Moore) do not form a natural group, but are cladistically interdigitated among two monophyletic New Zealand lineages (Tarastethus Sharp, and Trichopsida Larochelle and Larivière) suggesting substantial trans-Tasman diversification among these groups. Hypothesized relationships within Theprisa are consistent with two bouts of speciation involving the Bass Strait; an initial event establishing T. convexa as adelphotaxon to the other four species, and a more recent event establishing the sister species T. darlingtoni and T. montana. Geographic restriction of T. otway to the Otway Ranges is paralleled by Otway endemics in several other carabid beetle genera, as well as by endemics in numerous other terrestrial arthropod taxa. Whereas these numerous Otway endemics support the distinctive nature of the Otway Range fauna, their biogeographic relationships are extremely varied, illustrating that the Otways have accrued their distinctive biodiversity via various means.

The Otway Ranges contain many of the highest-wildfire-risk communities in Victoria, Australia. One of the chief risk mitigation measures in the Otway Ranges is planned burning. The location and amount of planned burning that is undertaken need to consider stakeholder perspectives that can be largely divergent, invoking difficult trade-offs for land-management agencies. The structured decision-making framework was utilised to select the most ‘appropriate’ 40-year cross-tenure fuel management strategy for the Otway Ranges. This paper details the approach undertaken to develop an optimised set of multi-objective fuel management strategies, identify suitable monetary and non-monetary objectives and calculate risk-weighted consequences using a range of modelling techniques. To underpin clarity in trade-offs and decision making, we emphasise the use of natural measures of performance for each candidate strategy against each objective, such as lives lost, species decline and economic losses associated with wildfire. This paper also highlights the role of stakeholder engagement throughout the decision-making process. We discuss the results of the formal trade-off process that was completed using an additive multi-objective value model to identify a preferred fuel management strategy for the Otway Ranges. The preferred strategy is currently used by local management agencies to guide operational planning and delivery.

Recent advances in cross-section balancing software have simplified the application of basic geometric constraints to the analysis of basin development. Geometric analysis of field and seismic data allows the user to verify initial interpretations and also elucidates important information about the structural evolution of a basin. Principally, computerised balancing and restoration of cross-sections assists in constraining:the amount of crustal extension;trap geometries, particularly fault geometries through time;the geometry of key horizons at any time, revealing basin morphology and migration paths;the time and amount of maximum burial and hence hydrocarbon migration; andthe likely mechanisms involved in basin evolution. In turn, these parameters can be used to further assess hydrocarbon prospectivity by providing useful data for lithospheric modelling.This study utilises 2D cross-section balancing software (Geosec™) to decompact, balance and restore a series of regional onshore-offshore cross-sections based on both reflection seismic data in the Torquay Embayment and field mapping in the Otway Ranges. The thickness of eroded strata has been constrained by Apatite Fission Track and Vitrinite Reflectance analyses. The resulting section restoration suggests that the eastern Otway Basin experienced extension of 26 per cent in the Early Cretaceous and that the Otway Ranges were subjected to −8 per cent shortening during mid-Cretaceous inversion and −4 per cent shortening during Mio-Pliocene inversion.The structural style of the Otway Ranges and Torquay Embayment is typified by steep, relatively planar, en echelon, N and NE-dipping Early Cretaceous extension faults that were subsequently inverted and eroded during the Cenomanian and Mio-Pliocene. The structural style of the region shows strong similarities with oblique- rift analogue models suggesting that the extensional history of the region was strongly controlled by prevailing basement fabric.Lower Cretaceous source rocks in the eastern Otway Basin reached maximum maturity prior to mid-Cretaceous inversion with the exception of parts of the Torquay Embayment which may not have experienced significant uplift and erosion at this time. The lack of subsidence in the eastern Otway Basin prevented the deposition of significant amounts of Upper Cretaceous sediments which are proven reservoirs in the western Otway Basin and Gippsland Basin. Subsequent Tertiary burial was insufficient, in most regions, to allow the source rocks re-enter the oil generation window.

That there is intraspecific variation in teat-number in Antechinus agilis (agile antechinus) and A. swainsonii (dusky antechinus) has been known for a long time. Our aim was to determine whether other key morphometric traits differed among individuals with different numbers of teats. External body dimensions and pelage characteristics were measured on live individuals and compared. Within-species variation in some external body dimensions (tail, pes, and snout-vent length) coincided with teat-number differentiation in both antechinus species in the Otway Ranges, Victoria. Disparities in pelage colour and markings were apparent between A. agilis 6- and 10-teat phenotypes, but were not obvious among A. swainsonii teat phenotypes. Although small sample sizes obviated statistical analysis, we tentatively concluded that female A. agilis with 7, 8, or 9 teats in the Otway Ranges probably displayed morphometric and pelage characteristics intermediate between those of 6- and 10-teat individuals. A comparison of morphometric traits among 6-teat A. agilis from different geographic areas (Otways, Portland and Wilsons Promontory) also revealed some variation. This result was consistent with an expectation of clinal variation in external morphology among antechinus. Overall, this study indicates that localized disparities that are associated with teat-number, as well as clinal differences occurring over large geographic distances, contribute to intraspecific variation in external morphology in antechinus.

Vitrinite reflectance data across the Otway Ranges yield a thermal maturity map that indicates the presence of a broad NE-SW trending anticline with strong vergence to the southeast. Surface Rv max values for the central part of the ranges are >1.5 whilst those on both limbs decrease to Apatite fission track analysis of seven Eumeralla (Lower Cretaceous) samples from the coast around Wye River yields an AFTA age of 90±5 Ma, consistent with similar cooling ages measured around most of the SE Australia margin. Modelling of the data is consistent with a stratigraphic age of -100 Ma, rapid heating to −80°C for −5 Ma followed by cooling from 95–80 Ma and further cooling in the Miocene.Geologically the very large asymmetric anticline can be explained by inversion of a thick rift sequence along a major, listric northwest-dipping fault, perhaps soling at mid-crustal levels. This is consistent with structures observed offshore in the Torquay Embayment and is being tested by the AGSO deep seismic profile BMR 920T1. Observed gravity highs in the Otway Ranges may be associated with inverted high density sediments. Fission track analysis indicates that the major cooling was at −90 Ma, which is therefore likely to be the time of inversion. However, this implies compression during continental breakup, the mechanisms of which are not fully understood.

The Eastern Otway Basin exhibits two near-or-thogonal structural grains, specifically NE-SW and WNW-ESE trending structures dominating the Otway Ranges, Colac Trough and Torquay Embayment. The relative timing of these structures is poorly constrained, but dip analysis data from offshore seismic lines in the Torquay Embayment show that two distinct structural provinces developed during two separate extensional episodes.The Snail Terrace comprises the southern structural province of the Torquay Embayment and is characterised by the WNW-ESE trending basin margin fault and a number of small scale NW-SE trending faults. The Torquay Basin Deep makes up the northern structural province and is characterised by the large scale, cuspate Snail Fault which trends ENE-WSW with a number of smaller NE-SW trending faults present.Dip analysis of basement trends shows a bimodal population in the Torquay Embayment. The Snail Terrace data show extension towards the SSW (193°), but this trend changes abruptly to the NE across a hinge zone. Dip data in the Torquay Basin Deep and regions north of the hinge zone show extension towards the SSE (150°). Overall the data show the dominance of SSE extension with a mean vector of 166°.Seismic data show significant growth of the Crayfish Group on the Snail Terrace and a lesser growth rate in the Torquay Basin Deep. Dip data from the Snail Terrace are therefore inferred to represent the direction of basement rotation during the first phase of continental extension oriented towards the SSW during the Berriasian-Barremian? (146-125 Ma). During this phase the basin margin fault formed as well as NE-SW trending ?transtensional structures in the Otway Ranges and Colac Trough, probably related to Palaeozoic features.Substantial growth along the Snail Fault during the Aptian-Albian? suggests that a second phase of extension affected the area. The Colac Trough, Otway Ranges, Torquay Embayment and Strzelecki Ranges were significantly influenced by this Bassian phase of SSE extension which probably persisted during the Aptian-Albian? (125-97 Ma). This phase of extension had little effect in the western Otway Basin, west of the Sorrel Fault Zone, and was largely concentrated in areas within the northern failed Bass Strait Rift. During the mid-Cretaceous parts of the southern margin were subjected to uplift and erosion. Apatite fission track and vitrinite reflectance analyses show elevated palaeotemperatures associated with uplift east of the Sorell Fault Zone.

A list of 37 species of ptyctimous mites from the State of Victoria, Australia, is provided. Seven species new for science are described and further seven are recorded for the first time in Victoria. The genus Arphthicarus has been discovered in Victoria and is represented by two new species. Zoogeographical distribution of each species is provided. Analysis of the ptyctimous fauna from four Victorian areas (Otway Ranges, Yarra Ranges, Errinundra Plateau and Strzelecki Ranges) has revealed that four species occur in a large number of specimens in one of the areas. Similarity analyses indicate that the faunas of Errinundra Plateau and Yarra Ranges are the most similar. An overview of state of knowledge on the ptyctimous mites from State of Victoria, Australia and Australasian Region is presented.

Abstract. Understanding the timescales of water flow through catchments and the sources of stream water at different flow conditions is critical for understanding catchment behaviour and managing water resources. Here, tritium (3H) activities, major ion geochemistry and streamflow data were used in conjunction with lumped parameter models (LPMs) to investigate mean transit times (MTTs) and the stores of water in six headwater catchments in the Otway Ranges of southeastern Australia. 3H activities of stream water ranged from 0.20 to 2.14 TU, which are significantly lower than the annual average 3H activity of modern local rainfall, which is between 2.4 and 3.2 TU. The 3H activities of the stream water are lowest during low summer flows and increase with increasing streamflow. The concentrations of most major ions vary little with streamflow, which together with the low 3H activities imply that there is no significant direct input of recent rainfall at the streamflows sampled in this study. Instead, shallow younger water stores in the soils and regolith are most likely mobilised during the wetter months. MTTs vary from approximately 7 to 230 years. Despite uncertainties of several years in the MTTs that arise from having to assume an appropriate LPM, macroscopic mixing, and uncertainties in the 3H activities of rainfall, the conclusion that they range from years to decades is robust. Additionally, the relative differences in MTTs at different streamflows in the same catchment are estimated with more certainty. The MTTs in these and similar headwater catchments in southeastern Australia are longer than in many catchments globally. These differences may reflect the relatively low rainfall and high evapotranspiration rates in southeastern Australia compared with headwater catchments elsewhere. The long MTTs imply that there is a long-lived store of water in these catchments that can sustain the streams over drought periods lasting several years. However, the catchments are likely to be vulnerable to decadal changes in land use or climate. Additionally, there may be considerable delay in contaminants reaching the stream. An increase in nitrate and sulfate concentrations in several catchments at high streamflows may represent the input of contaminants through the shallow groundwater that contributes to streamflow during the wetter months. Poor correlations between 3H activities and catchment area, drainage density, land use, and average slope imply that the MTTs are not controlled by a single parameter but a variety of factors, including catchment geomorphology and the hydraulic properties of the soils and aquifers.

Patterns of variation in the Eucalyptus globulus Labill. complex are reassessed by combining capsule measurements from an earlier study with recent collections, mainly of subspecies globulus. Four groups of populations are apparent and can be ascribed to the four subspecies maidenii, pseudoglobulus, bicostata and globulus. Intergrade populations between the latter three subspecies are widespread and mainly occur in the Otway Ranges and west Gippsland. There is a continuum in capsule morphology between the three-fruited subspecies, pseudoglobulus and bicostata. Subspecies globulus intergrades with these three-fruited intermediates. Three-fruited intergrade populations occuning north and south of the range of core pseudoglobulus can be differentiated and probably represent intergrades between pseudoglobulus and bicostata and between pseudoglobulus and globulus respectively. Reports of bicostata in the Furneaux Group and southern Victoria are thus probably erroneous and result from convergence in capsule morphology. The previously described taxon E. stjohnii (R. T. Bak.) R. T. Bak. is part of the continuum between subspecies pseudoglobulus and bicostata, but closer to pseudoglobulus. Populations phenotypically intermediate between and significantly different from globulus and the three-fruited intergrades are highly variable and occur in western Tasmania, on the northern end of Flinders Island, in the Otway Ranges and in west Gippsland. An isolated population on Rodondo Island is highly variable and has closest affinities to pseudoglobulus despite being within the geographical range of core globulus. The population from King Island is intermediate between the Otway phenotype and core globulus. The climatic regimes of the subspecies are markedly different and most three-fruited and globulus intergrade populations have closer climatic affinities to pseudoglobulus and globulus respectively. Hypotheses relating to the origin of the pattern of variation in E. globulus are discussed.

A well-dated pollen record from Chapple Vale in the north of the Otway region provides a detailed history of vegetation and environments through the last c. 7000 years. From the commencement of the record, a stand of cool temperate rainforest, dominated by Nothofagus cunninghamii (Hook.) Oerst., grew on or around the site and was surrounded by eucalypt-dominated tall open forest. Between c. 5200 and 4600 years BP (before present), the rainforest declined and tall open forest predominated. Some time after 4400 years BP there was a major and consistent increase in charcoal values, suggesting an increase in burning, the progressive development of scrub–heath vegetation on site and the replacement of tall open forest vegetation by eucalypt woodland surrounding the site. The fossil evidence for N. cunninghamii on the site and its present restriction to wetter areas and gullies of the Otway Ranges indicate, from the application of the present bioclimatic range of the species, a mean annual temperature and winter temperatures that were c. 1˚C cooler than present, and summer temperatures that were possibly slightly cooler than present, together with a much higher effective precipitation from the commencement of the record until c. 4600 years BP. These climatic estimates are in accord with those derived from a similar study of changing distributions of N. cunninghamii in the Central Highlands of lower mean annual and cooler summer temperatures and higher effective precipitation over this time span. However, for winter, the evidence is equivocal. While the Otway estimates suggest lower temperatures, the Central Highlands findings show slightly higher temperatures. Taking into account additional present-day records for N. cunninghamii, it is likely that the Otway estimates are the most reliable.

The plant pathogen, Phytophthora dnnamomi, is a cause of dieback disease observed in sclerophyll vegetation in Australia, The effects of P. dnnamomi on flora and fauna were studied at two locations in heathland vegetation near the coastal town of Anglesea, Victoria. The pathogen was isolated from soils beneath diseased heathland plants. The extent of diseased vegetation was assessed by the presence and absence of highly sensitive indicator species, Xanthorrhoea australis and hopogon ceratophyllus. The characteristics of heathland vegetation exhibiting dieback disease associated with the presence of P. dnnamomi were investigated. Plant species richness was similar between diseased and non-diseased areas however diseased areas were characterised by significant declines in the cover and frequency of susceptible species, increases in resistant species and increases in percent cover of open ground. Compared to non-diseased areas, diseased areas exhibited fewer shrub species and decreased shrub cover. The percentage cover and number of species of sedges, lilies and grasses were higher in diseased areas. Structural differences were significant between 0-0.6 m with decreased cover of vegetation in diseased areas. Differences in structure between diseased and non-diseased areas were not as great as expected due to increases in the cover of resistant species. A number of regenerating X australis were observed in post-disease areas. Cluster analysis of floristic data could clearly separate diseased and non-diseased trap stations. The population dynamics and habitat use of eight small mammal species present were compared in diseased and non-diseased areas using trapping and radio-tracking techniques. The number of small mammal species captured in post-disease areas was significantly lower than non-diseased areas. Mean captures of Antechinus stuartii and Rattus fiisdpes were significantly lower in diseased areas on Grid B. Mean captures of Rattus lutreolus were significantly lower in diseased areas on both study grids. Significant differences were not observed in every season over the two year study period. Radio tracking revealed more observations of Sminthopsis leucopus in non-diseased vegetation than in diseased. Cercartetus nanus was frequently observed to utilise the disease susceptible X. australis for nesting. At one location, the recovery of vegetation and small mammal communities in non-diseased and diseased vegetation after fuel reduction burning was monitored for three years post-fire. Return of plant species after fire in both disease classes were similar, reaching 75% of pre-fire richness after three years. Vegetation cover was slower to return after fire in diseased areas. Of the seven small mammal species captured pre-fire, five were regularly captured in the three years after fire. General linear model analysis revealed a significant influence of disease on capture rates for total small mammals before fire and a significant influence of fire on capture rates for total small mammals after fire. After three years, the influence of fire on capture rates was reduced no significant difference was detected between disease classes. Measurements of microclimate indicate that diseased, burnt heathland was likely to experience greater extremes of temperature and wind speed. Seeding of diseased heathland with X. australis resulted in the establishment of seedlings of this sensitive species. The reported distributions of the mamma] species in Victoria were analysed to determine which species were associated with the reported distribution of dieback disease. Twenty-two species have more than 20% of their known distribution in diseased areas. Five of these species, Pseudomys novaehollandiae, Pseudomys fumeust Pseudomys shortridgei, Potorous longipes and Petrogale pencillata are rare or endangered in Victoria. Four of the twenty-two species, Sminthopsis leucopus, Isoodon obesulus, Cercartetus nanus and Rottus lutreolus am observed in Victorian heathlands. Phytophthora cinnamomi changes both the structure and floristics of heathland vegetation in the eastern Qtway Ranges. Small mammals respond to these changes through decreased utilisation of diseased heathland. The pathogen threatens the diversity of species present and future research efforts should be directed towards limiting its spread and rehabilitating diseased areas.

The relationship of vegetation and disturbance factors to the distribution, abundance and diversity of small mammals in the eastern Otway region, Victoria were investigated. Antechinus stuartii, Rattus fuscipes and Rattus lutreolus were widely distributed and occurred in the majority of the eleven floristic vegetation groups identified. Antechinus minimus, Antechinus swainsonnii and Pseudomys novaehollandiae had restricted distributions and were recorded in only two or three vegetation groups. New information on the distribution of the rare species P. novaehollandiae, was obtained and two floristically rich vegetation groups that it preferred were identified. Species-rich small mammal communities occurred in vegetation communities with high numbers of sclerophyll plant species and high structural diversity. Maximum food resources were considered to be provided in these communities. Local habitat diversity was also correlated with species-richness. Small mammal abundance was maximum in non-sclerophyllous canmunities, where high plant productivity was considered to be important. For the first time, the presence of the plant pathogen Phytophthora cinnamomi was shown to affect small mammals. It was associated with small mammal communities of low species richness and abundance, Recovery of small mammal populations after wildfire was slow until the fourth year. Mus musculus reached peak abundance from 2-3 years and then declined rapidly. P. novaehollandiae was the only native species that achieved maximum abundance early in the succession. A. stuartii, R. fuscipes and R. lutreolus approached maximum abundance in mid-succession, while Isoodon obesulus was a mid- to late-successional species. A. minimus survived the fire, but did not persist after one year. The pattern of succession was influenced by attributes of species, such as survival after fire, their ability to disperse and reproduce.

This visually superb and informative field guide is the second volume of Flora of the Otway Plain and Ranges, and covers more than 480 species of Daisies, Heaths, Peas, Saltbushes, Sundews, Wattles and other shrubby and herbaceous Dicotyledons. The illustrated family key is unique and covers 75 families and over 200 genera. Each species is illustrated and labels provide a clear key to identification for botanists and amateurs alike. The Otway region of Victoria, with its temperate rainforests, mountain ash forests, heathlands, plains and coastal dunes, has an extraordinarily rich and diverse flora.

The Otway region of Victoria, with its temperate rainforests, mountain ash forests, heathlands, plains and coastal dunes, has an extraordinarily rich and diverse flora. The first volume of Flora of the Otway Plain and Ranges covers the orchids, irises, lilies, grass-trees, mat-rushes and other petaloid monocotyledonous plants. Enid Mayfield's exquisite colour illustrations of more than 200 species reveal tiny botanical details which enable the untrained botanist to identify each species with ease. The section on orchids describes and illustrates more than 130 species, highlighting their fascinating adaptations for attracting specific pollinating insects. The clear text and illustrations frequently draw attention to the relationship of plants to the broader environment, the impact of fire, the role of pollinators and the importance of fungi.

The Otways and Shipwreck Coast is known for its natural beauty and attracts millions of visitors each year, particularly along the Great Ocean Road. The value of the region's rich biodiversity is recognised at the national and global level and its wildlife is markedly different to other regions, including eastern Victoria which supports similar vegetation types. Wildlife of the Otways and Shipwreck Coast is a photographic field guide to the vertebrate wildlife of Victoria’s south-west. It covers all the mammals, birds, reptiles and frogs that occur in the region, including on land and in coastal waters. Each of the 288 species profiles includes a description and information on identification, range, conservation status, habitat use and ecology and is complemented by an exquisite colour photograph and a detailed distribution map. The book also includes chapters on habitat types, conservation and management, and on 14 key places in the region to view wildlife. This book will allow those interested in wildlife, including residents and visitors, to identify vertebrate animals found in the region. Readers will also become more familiar with the distinct role the Otways has in conserving Australia’s biodiversity.