The dynamic regeneration niche of a forest following a rare disturbance event

Aim: Knowledge of how climate and fire regimes affect regeneration in foundation species is critical to the conservation of entire ecosystems. Different stages of regeneration often require different ecological conditions, but dynamic constraints on regeneration are poorly known for species that regenerate only after infrequent wildfires. Focussing on a long-lived, foundation tree species (Eucalyptus regnans), we tested the hypothesis that the relative importance of fire regime variables (fire severity and time since previous fire) and environmental gradients on post-fire regeneration would shift as seedlings developed. Location: South-eastern Australia. Methods: Following a large (> 59,000 ha) summer wildfire in 2009, we sampled 131 sites (61 burnt) annually for four years (2009-2012), representing the range of environmental conditions in which E. regnans occurs. We analysed the effect of fire severity, time since fire and environmental variables on early regeneration processes critical for post-fire species distributions: seedling establishment, seedling density and growth through different height stages (10 cm, 25 cm, 50 cm and 200 cm). Results: The regeneration niche of E. regnans was defined by different factors at different stages of development. Initially, seedlings established prolifically on burnt sites, regardless of severity. Three years into the regeneration process, high-severity fire became the dominant driver of seedling persistence and growth over 25 cm. Growth over 50 cm was dependent on environmental conditions relating to elevation and precipitation. Main conclusions: Our results describe how fire occurrence, fire severity and environmental gradients affected seedling establishment, persistence and growth. The dynamic constraints on regeneration likely reflect temporal changes in the biotic and abiotic environment and variation in resource requirements during the early post-fire years. Our findings will enable more accurate forecasts of species distributions to assist forest conservation in the face of global changes in climate and fire regimes.

Effects of multiple disturbance processes on arboreal vertebrates in Eastern Australia: implications for management

Habitat loss and invasive predators increasingly threaten global biodiversity. Here we use a landscape-scale experimental approach to explore the individual and synergistic effects of logging and an invasive predator, the red fox Vulpes vulpes on two common native arboreal vertebrates (a predator and prey species) in south-eastern Australia. We used site occupancy methods to evaluate different models evaluating the effects of site specific forest logging disturbance, lethal fox baiting and forest structural elements for explaining variation in site occupancy of a large monitor lizard Varanus varius, and a marsupial prey, the common ringtail possum Pseudocheirus peregrinus across a complex forest landscape. Site occupancy of ringtail possum was influenced by habitat resources and the structural complexity of forest, which indirectly mediated predation risk. Presence of fox baiting had no direct effect on the ringtail site occupancy. In contrast, access to prey resources and fox baiting appeared to best explain site occupancy variation in monitor lizards across the landscape. While these species are affected primarily by separate disturbances, synergistic interactions between the processes may intensify their effects. Our results demonstrate that species susceptibility to disturbance processes are highly idiosyncratic. This approach makes efficient use of integrated modelling to aid conservation management at both local and landscape levels.

Evaluating the role of fire disturbance in structuring small reptile communities in temperate forests

Fire is an integral disturbance shaping forest community dynamics over large scales. However, understanding the relationship between fire induced habitat disturbance and biodiversity remain equivocal. Ecological theories including the intermediate disturbance hypothesis (IDH) and the habitat accommodation model (HAM) offer predictive frameworks that could explain faunal responses to fire disturbances. We used an 80 year post-fire chronosequence to investigate small reptile community responses to fires in temperate forests across 74 sites. First, we evaluated if changes in species richness, abundance and evenness post-fire followed trends of prior predictions, including the IDH. Second, using competing models of fine scale habitat elements we evaluated the specific ways which fire influenced small reptiles. Third, we evaluated support for the HAM by examining compositional changes of reptile community post-fire. Relative abundance was positively correlated to age post-fire while richness and evenness showed no associations. The abundance trend was as expected based on the prior prediction of sustained population increase post-disturbance, but the trend for richness contradicted the prediction of highest diversity at intermediate levels of disturbance (according to IDH). Abundance changes were driven mainly by changes in overstorey, ground layer, and shelter, while richness and evenness did not associate with any vegetation parameter. Community composition was not strongly correlated to age since fire, thus support for the HAM was weak. Overall, in this ecosystem, frequent fire disturbances can be detrimental to small reptiles. Future studies utilizing approaches based on species traits could enhance our understanding of biodiversity patterns post-disturbance.

Identifying the location of fire refuges in wet forest ecosystems

The increasing frequency of large, high-severity fires threatens the survival of old-growth specialist fauna in fire-prone forests. Within topographically diverse montane forests, areas that experience less severe or fewer fires compared with those prevailing in the landscape may present unique resource opportunities enabling old-growth specialist fauna to survive. Statistical landscape models that identify the extent and distribution of potential fire refuges may assist land managers to incorporate these areas into relevant biodiversity conservation strategies. We used a case study in an Australian wet montane forest to establish how predictive fire simulation models can be interpreted as management tools to identify potential fire refuges. We examined the relationship between the probability of fire refuge occurrence as predicted by an existing fire refuge model and fire severity experienced during a large wildfire. We also examined the extent to which local fire severity was influenced by fire severity in the surrounding landscape. We used a combination of statistical approaches, including generalized linear modeling, variogram analysis, and receiver operating characteristics and area under the curve analysis (ROC AUC). We found that the amount of unburned habitat and the factors influencing the retention and location of fire refuges varied with fire conditions. Under extreme fire conditions, the distribution of fire refuges was limited to only extremely sheltered, fire-resistant regions of the landscape. During extreme fire conditions, fire severity patterns were largely determined by stochastic factors that could not be predicted by the model. When fire conditions were moderate, physical landscape properties appeared to mediate fire severity distribution. Our study demonstrates that land managers can employ predictive landscape fire models to identify the broader climatic and spatial domain within which fire refuges are likely to be present. It is essential that within these envelopes, forest is protected from logging, roads, and other developments so that the ecological processes related to the establishment and subsequent use of fire refuges are maintained.

Lizard responses to forest fire and timber harvesting: complementary insights from species and community approaches

Understanding the relationship between community composition and ecosystem function is essential for managing forests with complex disturbance regimes. Studies of animal responses to fire and timber harvesting in forest ecosystems typically focus on a single level of community diversity. Measures of species abundance and diversity at the community level, along with measures of functional diversity that incorporate information on species traits, provide opportunities for complementary insights into biodiversity responses to disturbances. We quantified community and functional responses of a temperate forest lizard community to fire and rotational logging using metrics including species-specific abundance, community abundance, species richness and evenness, as well as trait-based measures of functional diversity. We used non-linear regression models to examine the relationships between reptile data and time since fire and timber harvesting, using sites arrayed along a 30-years post-disturbance chronosequence. We modelled responses separately in two major vegetation types: coastal Banksia woodland and lowland eucalypt forests. Species and community measures offered different insights into the role of fire and logging. Species responses to disturbance differed between disturbance type and vegetation type. Four species exhibited significant population responses to either fire or timber harvesting, while the rest were unaffected by either disturbance. At the community level, species richness and community abundance increased significantly with time since fire in woodland vegetation. In forest vegetation, community abundance decreased with time since fire. Surprisingly, community evenness and functional diversity did not show marked responses to fire or timber harvesting. This is likely a result of trait homogeneity and the asynchrony in species responses to disturbance. We advocate using multiple measures of community composition - incorporating species-specific information, community metrics and functional traits - to ensure a more holistic understanding of disturbance ecology in forest landscapes.

Urbanisation and the ecology of powerful owls ninox strenua in outer Melbourne, Victoria

Historically, the Powerful Owl (Ninox strenua) has been seen as a southeastern Australian species restricted to, or most numerous in, dense gullies of tall open forests in hilly or mountainous areas of the coast and Great Divide. However, recent research has revealed that Powerful Owls may breed numerously and successfully in a wider range of habitats than previously believed, including the forests and woodlands within the metropolitan areas of some major cities.Here we report on the breeding of a number of pairs of Powerful Owls in the Yarra Valley, Victoria. Study sites ranged from relatively undisturbed, wet sclerophyll forest 80 km from central Melbourne, through dry sclerophyll, eucalypt-dominated open forest with some disturbance, to a highly disturbed urban parkland only 18 km from central Melbourne. We found that Powerful Owls breed successfully in some urban areas, but are limited in the amount of human disturbance they can tolerate near their nesting hollow. In the most heavily utilized section of the urban parkland, all breeding attempts were unsuccessful and in one year the young were apparently eaten by one of the parents. This followed construction of a timber boardwalk under the nest tree during the breeding season. The Powerful Owls subsequently moved to a more secluded nesting hollow and raised two young. Recommendations for management of Powerful Owls in urban areas are discussed in the context
of these results.

Children's body image concerns and eating disturbance: a review of the literature

In recent years a large number of studies have examined body image concerns, and early symptoms of eating disturbance among children. However, to date there has been no synthesis or evaluation of these studies. The purpose of the present article is to review and evaluate the research that has examined body image concerns, and eating attitudes and behaviors among children 6 to 11 years of age. The instruments used to assess body image concerns and eating disturbance in children closely resemble those used with adolescents and adults. Overall, the psychometric data for these instruments are very good and there is sufficient evidence indicating that they can be used reliably and validly. In addition, similar variables to those studied in adolescent and adult samples have been found to be associated with children's body image concerns and early eating disturbance. These include gender, age, body mass index, race, sociocultural pressures, and self-concept. Our understanding of the development of body image concerns and eating disturbance in children is limited, however, by the fact that most of the research in this field has been based on cross-sectional data, and the studies have focused almost exclusively on weight-loss cognitions and behaviors.

The influence of time since fire and distance from fire boundary on the distribution and abundance of arboreal marsupials in Eucalyptus regnans-dominated forest in the Central Highlands of Victoria

The impact of time since fire after two consecutive wildfires 44 years apart (1939 and 1983) within the same area, and the distance from the fire boundary «100 m or 500-2000 m), were investigated in relation to the distribution and abundance of arboreal marsupials in 1994. Arboreal marsupials were censused by stagwatching and spotlighting in two relatively young age classes of mountain ash (Eucalyptus regnans) dominated forest in the Central Highlands of Victoria. Five species of arboreal marsupial were detected, but only three were detected in sufficient numbers to determine habitat preferences. Petauroides volans (greater glider) was statistically more abundant in 1939 regrowth forests, while Trichosurus caninus (mountain brushtail possum) showed no significant preference for either age class of forest. All but one record of Gymnobelideus leadbeateri (Leadbeater's possum) came from young forest, though the effect of age-class was not statistically significant. Distance from fire boundary explained little or no variation in mammal distribution or abundance. While the actual number of hollow-bearing trees was similar in both age classes of forest, the long-term lifespan of hollow-bearing trees in more recently burnt forest is predicted to be lower than in unburnt or not recently burnt forest. Post-fire salvage logging following the 1983 wildfires appears to have reduced the number of hollow-bearing trees at sites burnt in 1983.

Nematode assemblages from Avicennia marina leaf litter in a temperate mangrove forest in south-eastern Australia

Meiofauna from Avicennia marina leaf litter in a temperate mangrove forest was enumerated, and the nematode assemblages compared on the bases of leaf colour (used as a guide to leaf age) and shore horizon where samples were collected. Twenty-one putative nematode species were collected from 48 leaf litter samples. Univariate analyses indicated that neither the colour of the leaf nor the shore horizon significantly affected abundance of nematodes. However, of the four (222) treatment groups, rarefaction curves revealed highest diversity on brown leaves from under the shade of the tree canopy (H'=0.751-0.126 SE, n=17). Species diversity of leaf litter nematodes was lower in this temperate mangrove system than reported from tropical mangrove studies. ANOSIM tests confirmed a significant effect of shore horizon on nematode assemblages. The dominant feeding group among nematodes was non-selective deposit feeders (7/21 species, but 77% of all nematodes). Epigrowth grazers were represented by 8/21 species of nematodes, but only 19% of the total number. Excised leaves became skeletonised by about 15 weeks. Shorter temporal scales of life cycles of nematodes compared with leaf degradation, and the dynamic nature of epibiontic assemblages, probably explain the similar assemblage structure on yellow and brown leaves.

Beach-foraging behaviour of Forest Ravens Corvus tasmanicus and an Australian Magpie Gymnorhina tibicen at Wilsons Promontory, Victoria

Observations are presented of Forest Ravens Corvus tasmanicus, and an Australian Magpie Gymnorhina tibicen, foraging by gleaning the sand on a beach.

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)

Meiofaunal recruitment to mimic pneumatophores in a cool-temperate mangrove forest: spatial context and biofilm effects

A field experiment was devised to test whether meiofauna that colonised mimic pneumatophores (artificial substrates) resembled the assemblage on adjacent live pneumatophores in three randomly chosen intertidal, estuarine sites. The experiment showed that the close proximity of particular biota on living pneumatophores did not reliably influence subsequent development of assemblages upon mimic pneumatophores within a scale of 10 m during a colonisation period of less than 20 weeks. There was some convergence of the composition of the colonising assemblage of meiofauna on mimic pneumatophores with the local assemblages in sites dominated by barnacles, or where the natural pneumatophores were free from macroscopic epibionts. However, tychopelagic meiofauna from algal epiphytes did not significantly colonise mimic pneumatophores during the 20-week trial, probably due a lack of growing algae. During the conditioning phase suspended in water at a marine site 20 km from the mangroves, mimic pneumatophores acquired an assemblage of meiofauna different from the estuarine assemblage that colonised mimics following implantation in the estuarine mudflat. Enhanced colonisation rates of mimics in suspended bags at the conditioning site may be explained by the absence of benthic macroinvertebrates, and the lack of intertidal exposure. Biofilms aged 2, 7, and 11 weeks had no consistent, different effect on the subsequent colonisation of meiofauna. We conclude that divergence of phytal-based assemblages of meiofauna depends upon the amount of coverage, as well as the type, of fouling macro-epibionts on the pneumatophores. Meiofaunal assemblages on artificial substrates after 20 weeks colonisation displayed less intrinsic patchiness than mature phytal assemblages on natural pneumatophores, and so present a potentially useful way of improving the power of biomonitoring applications using meiofauna.

Cultural orienteering: a map for Anthony Browne`s into the forest

Bullen and Parsons identify Anthony Browne's picture book Into the Forest as a re-gendered retelling of 'Little Red Riding Hood' that expresses recent assumptions about childhood, risk and the resources children need to survive in today's world. In Browne's version, the forest is the terrain in which a young male protagonist imaginatively explores his anxiety about his father's unexplained absence.

Feel blue? Touch green! Participation in forest/woodland management as a treatment for depression

Recent research by a team from Deakin University explored the health and wellbeing benefits of civic environmentalism – voluntary communal actions undertaken to promote ecosystem sustainability, typified by membership of a ‘friends of parks’ group. The research confirmed what was known intuitively: that belonging to such a group and undertaking the activities associated with such a group exposes people not only to the benefits of the natural environment, but also to other people and to opportunities to make a contribution which is socially valued.

On the basis of those findings, a pilot project involving intentional engagement of people suffering depression and related disorders in supported nature-based activities in a woodland environment is being implemented and evaluated. This article reports on that project and discusses the implications of its findings to date, and the findings of the three earlier projects, both for urban woodland/forest managers and for the health sector.

As this contribution indicates, there appears to be potential for the use of civic environmentalism to promote health, wellbeing and social connectedness for individuals and the wider population, as well as for groups with identified health vulnerabilities. However, the realization of the benefits of such an approach will be dependent on co-operation between the environment and health sectors to create and promote opportunities for increased civic environmentalism, and to identify and address the barriers to their effective use.

The diet of powerful owls (Ninox strenua) and prey availability in a continuum of habitats from disturbed urban fringe to protected forest environments in south-eastern Australia

This study investigates the diet of six breeding pairs of powerful owls in the Yarra Valley Corridor in Victoria, Australia, and compares prey consumption with prey availability. The six sites represent a continuum of habitats, ranging from urban Melbourne, through the urban fringe interface to a more forested landscape. We found that powerful owls in the Yarra Valley Corridor are reliant almost exclusively on arboreal marsupial prey as their preferred diet, with 99% of their overall diet comprising four arboreal marsupial species. These four species (the common ringtail possum, common brushtail possum, sugar glider and greater glider) were also the most abundant species observed while spotlighting; however, their abundance varied along the continuum. There was a strong positive relationship with the presence of these species in the diet and their site-specific availability, indicating that the powerful owl is a generalist hunter, preying on the most available prey at a given site and in a given season. This study suggests that food resources are high in these disturbed urban fringe sites and it is unlikely that food availability in urban environments will limit the potential survival of urban powerful owls.