Terrestrial detritus supports the food webs in lowland intermittent streams of south-eastern Australia : a stable isotope study

1. Large amounts of terrestrial detritus enter many low-order forested streams, and this organic
material is often the major basal resource in the metazoan food webs of such systems. However,
despite their apparently low biomass, algae are the dominant food of organisms in a number of
aquatic communities which conventionally would have been presumed to be dependent on
allochthonous detritus, particularly those in the tropics and also in lowland intermittent streams
in arid Australia.
2. The dual stable isotope signatures (d13C and d15N) of potential primary food sources were
compared with the isotopic signatures of common aquatic animals in lowland intermittent
streams in south-eastern Australia, in both spring and summer, to determine whether
allochthonous detritus was an important nutritional resource in these systems. The isotopic
signatures of the major potential allochthonous plant food sources (Eucalyptus, Phalaris and
Juncus) overlapped, but were distinct from algae and the dominant macrophytes growing in the
study reaches. The isotopic signatures of biofilm were more spatially and temporally variable
than those of the other basal resources.
3. Despite allochthonous detritus having relatively high C : N ratios compared to other
potential basal resources, results from ISOSOURCE mixing model calculations demonstrated
that this detritus, and the associated biofilm, were the major energy sources assimilated by
macroinvertebrate primary consumers in both spring and summer. The importance of these
energy sources was also reflected in animals higher in the food web, including predatory
macroinvertebrates and fish. These resources were supplemented by autochthonous sources of
higher nutritional value (i.e. filamentous algae and macrophytes, which had relatively low
C : N ratios) when they became more prolific as the streams dried to disconnected pools in
summer.
4. The results highlight the importance of allochthonous detritus (particularly from Eucalyptus)
as a dependable energy source for benthic macroinvertebrates and fish in lowland intermittent
streams of south-eastern Australia. This contrasts with previous stable isotope studies
conducted in lowland intermittent streams in arid Australia, which have reported that the fauna
are primarily dependent on autochthonous algae.

A new Brachiopod fauna from the early to middle permian of Southern Qinghai Province, Northwest China

A new brachiopod fauna is described from the Early and Middle Permian of Zadoi and Zhidoi counties, southern Qinghai (Changdu block), northwest China. This fauna includes 13 species in nine genera with Spinomarginifera concentrica n. sp. and Transennatia waterhousei n. sp. The Early to Middle Permian brachiopod fauna from southern Qinghai is very similar to the contemporary Cathaysian faunas of South China with which the new fauna shares 70 per cent of its species. On the other hand, the Qinghai brachiopods also demonstrate a significant link with the Permian brachiopod fauna of the Sino-Mongolian-Japanese Province in northeast China, as suggested by Marginifera septentrionalis and Attenuatella. In particular, the occurrence of the bipolar brachiopod genus Attenuatella suggests that southern Qinghai may have played an important role as a biogeographic stepping stone in the marine faunal interchanges between the northern and southern hemispheres during the Early and Middle Permian.

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.

Studies on Australian hydroids : the genus Eudendrium and the fauna of the seagrass Amphibolis

An important Athecate genus, Eudendrium, and a group of species of the Thecata, the latter ecologically related by life on a common substrate, are reviewed. Eudendrium, hitherto poorly known in Australia, comprises 17 species, including 10 undescribed species with 71% Australian, and high provincial endemicity. Eudendrium may be a shelf genus avoiding turbulent oceanic waters. Species of Eudendrium are predominantly epizoic and some gregariously settling colonies may live for five years. Identification of sterile material is refined by using the cnidome in a key to classification. The species and population dynamics of hydroid epiphytes of the endemic southern Australian marine angiosperm Amphibolis were investigated with revision of historically vexatious taxa. In contrast with the northern hemisphere, no Athecata are associated with southern Australian seagrasses. Seventeen species from eight thecate families are associated with the two species of Amphibolis, including one undescribed species, H&lecium amphibolum, and one new record for Australia, Aglaophenia postdentata. The Lineolariidae is revised and a new genus, Millardaria, erected for a species from seagrass in Madagascar. The high endemicity (58%) and host-specificity of hydroids to Amphibolis is an evolutionary consequence of isolation of the seagrass dating from break-up of the Tethyan Sea. Hydroids occur throughout the year in the Amphibolis leaf canopy with a mean annual epiphytism of 44% on A. antarctica in the eastern continent and 86% in the western continent; epiphytism is 52% on A. griffithii in the western continent. Half of the eight important species are dominant epiphytes across the southern continent but the species and order of abundance varies regionally. Most are pioneer colonists with short, repetetive life-cycles lasting from weeks to a few months. Three species epiphytise the seagrass stems but only one is a leaf-canopy dominant. The canopy community comprises small, fast-growing species or dwarfed variants of species larger in other habitats: these ecomorphically constant forms are associated only with seagrass. Strategies for survival in the harsh Amphibolis environment include adnate colonies and gonothecae adnate or recumbent to the substrate, marked strengthening of the hydrorhiza, various hydrodynamic adaptations of the hydrotheca, early maturation and production of numerous small ova.

Effects of phytophthora cinnamomi on heathland flora and fauna of the Eastern Otway Ranges

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.

A late Changhsingian (latest Permian) deep-water brachiopod fauna from Guizhou, South China

A deep-water brachiopod fauna (20 species in 19 genera) is described from the Late Permian Shaiwa Group of Ziyun, Guizhou, South China. New species include Pygmochonetes? shaiwaensis and Martinia ziyunensis. This fauna is associated with deep-water assemblages of pelagic radiolarians, foraminifers, bivalves and ammonoids. The brachiopod faunal correlations and age constraints of the associated fossil groups suggest that the Shaiwa fauna is late Changhsingian (latest Permian) in age. The Shaiwa fauna superficially resembles the coeval deep-water assemblage from Guangxi, South China; both are characterized by a mixture of deep-water brachiopods and shallow-water elements.

A new bivalve fauna from the Permian-Triassic boundary section of southwestern China

A new marine bivalve fauna from the continuous Upper Permian Longtan Formation to Lower Triassic Yelang Formation of the Zhongzai section in southwestern China is documented. Four bivalve assemblages spanning the Permian–Triassic boundary are recognized and regionally correlated in South China. The bivalve assemblages changed from elements dominated by Palaeozoic types to those dominated by Mesozoic types. Three new species, Claraia zhongzaiensis sp. nov., Claraia sp. nov. 1 and Claraia sp. nov. 2, are described.

Influence of disturbance on threatened fauna and associated habitat, Victoria

Results of fauna and vegetation surveys conducted around Portland Aluminium smelter between 1979 and 2004 found small mammal abundance and diversity had declined and changes in vegetation communities were related to changes in fire patterns, vegetation fragmentation and weed invasion. Small mammal numbers were greater in nearby National Parks.

Effects of Phytophthora cinnamomi on heathland fauna and ecosystem function

Progression of disease caused by the plant pathogen Phytophthora cinnamomi was correlated to rainfall events and resulted in a loss of plant species diversity in heathland vegetation at Anglesea, Victoria. Lower captures of small mammals were recorded in diseased areas. Management of disease using the chemical phosphite was also evaluated.

Interannual variation in pup production and the timing of breeding in benthic foraging Australian fur seals

¯Large interannual variations in reproductive success caused by fluctuations in oceanography and prey availability are common to many species of air breathing epipelagic predators. In contrast, little is known about variation in benthic foragers such as Australian fur seals (Arctocephalus pusillus doriferus). Between 1997 and 2007, pup production was assessed in 9 yr, while the timing of breeding and adult female condition was assessed in 5 yr at Kanowna Island in Bass Strait, southeastern Australia. Pup production was variable ( ¯x = 1,726 ± 42, range = 1,386–2,301), but without temporal trend, as was median birth date ( ¯x = 23 November±1, range = 21–25 November) and pupping synchrony (period of 90% births: ¯x = 28 ± 2 d, range = 23–31 d). Pup production was negatively correlated with median birth date and positively correlatedwith female condition,winter sea-surface temperature (SST) and zonal wind strength within Bass Strait. Pup production was also negatively correlated with SST in the previous summer within Bass Strait and in the eastern Great Australian Bight upwelling region. The results suggest that the reproductive success of Australian fur seals is influenced by oceanography but less so than in otariids foraging epipelagically in major upwellings. Despite spanning several El Niño events, no correlation between pup production and the Southern Oscillation Index was observed.

Comparison of automated classification techniques for predicting benthic biological communities using hydroacoustics and video observations

The effective management of our marine ecosystems requires the capability to identify, characterise and predict the distribution of benthic biological communities within the overall seascape architecture. The rapid expansion of seabed mapping studies has seen an increase in the application of automated classification techniques to efficiently map benthic habitats, and the need of techniques to assess confidence of model outputs. We use towed video observations and 11 seafloor complexity variables derived from multibeam echosounder (MBES) bathymetry and backscatter to predict the distribution of 8 dominant benthic biological communities in a 54 km² site, off the central coast of Victoria, Australia. The same training and evaluation datasets were used to compare the accuracies of a Maximum Likelihood Classifier (MLC) and two new generation decision tree methods, QUEST (Quick Unbiased Efficient Statistical Tree) and CRUISE (Classification Rule with Unbiased Interaction Selection and Estimation), for predicting dominant biological communities. The QUEST classifier produced significantly better results than CRUISE and MLC model runs, with an overall accuracy of 80% (Kappa 0.75). We found that the level of accuracy with the size of training set varies for different algorithms. The QUEST results generally increased in a linear fashion, CRUISE performed well with smaller training data sets, and MLC performed least favourably overall, generating anomalous results with changes to training size. We also demonstrate how predicted habitat maps can provide insights into habitat spatial complexity on the continental shelf. Significant variation between patch-size and habitat types and significant correlations between patch size and depth were also observed.

Ecological notes on the East Gippsland burrowing crayfish Engaeus orientalis, including burrow structure and associated fauna

Despite Australia having a high diversity of freshwater crayfish species, the ecology of many of these species remains poorly known, particularly burrowing crayfish of the genus Engaeus. Biological information on colour, behaviour, burrow structure, associated burrow fauna and habitat of the East Gippsland Burrowing Crayfish Engaeus orientalis obtained during incidental observations in 2007 and 2008 is provided. The burrow structure took the form of radiating runways under a rock slab, while the burrow location was in a semi-disturbed site away from water. Both are atypical for this species.