Mark G. Tozer's research while affiliated with UNSW Sydney and other places

Publications (37)

Article
Full-text available
Megafire events generate immediate concern for wildlife and human well‐being, but their broader ecological impacts likely extend beyond individual species and single fire events. In the first mechanistic study of fire effects focussed on ecosystems, we aimed to assess the sensitivity and exposure of ecosystems to multiple fire‐related threats, plac...
Article
Full-text available
The 2019–20 Australian fire season was heralded as emblematic of the catastrophic harm wrought by climate change. Similarly extreme wildfire seasons have occurred across the globe in recent years. Here, we apply a pyrogeographic lens to the recent Australian fires to examine the range of causes, impacts and responses. We find that the extensive are...
Article
Full-text available
Ecological community and ecosystem “red lists” have been developed in several jurisdictions to improve ecosystem‐level biodiversity protection. However, a challenge for the conservation and management of listed ecosystems is consistent identification in the field or from plot records. Ecosystem descriptions must have enough detail for positive iden...
Article
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The Bendethera Shrublands are a unique and fascinating ecological community restricted to less than 100 hectares on a series of steep limestone outcrops in the Deua River valley. The community is characterised by a dense shrub layer to around 7.5 metres height and dominated by Acacia covenyi, a locally endemic species, whose blue foliage forms a st...
Article
The influence of wildfire on surface soil and hydrology has been widely investigated, while its impact on the karst vadose zone is still poorly understood. A moderate to severe experimental fire was conducted on a plot (10 m × 10 m) above the shallow Wildman's Cave at Wombeyan Caves, New South Wales, Australia in May 2016. Continuous sampling of wa...
Article
Fire dramatically modifies the surface environment by combusting vegetation and changing soil properties. Despite this well-documented impact on the surface environment, there has been limited research into the impact of fire events on karst, caves and speleothems. Here we report the first experiment designed to investigate the short-term impacts o...
Article
Global change is threatening ecosystems and biodiversity worldwide, creating a pressing need to understand how climate and disturbance regimes interact and influence the persistence of species. We quantify how three ecosystem drivers – rainfall, fire and herbivory – influence vital rates in the perennial resprouting graminoid, Triodia scariosa, a f...
Article
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Wildfires reduce soil CO2 concentration by destroying vegetation and soil-dwelling microbes, thus reducing soil respiration. Post-fire vegetation recovery is primarily determined by vegetation growth forms and modes of regeneration, whereas long-term recovery of soil microbes is largely dependent on vegetation rehabilitation. With previous research...
Conference Paper
Wildfires dramatically change the surface environment by removing vegetation and soil microbial communities and altering soil structure and geochemistry. Karst subsurface processes such as dissolution, cave formation and speleothem deposition are sensitive to environmental change, which is precisely why speleothems have been widely used as recorder...
Article
1.Theory suggests spatial heterogeneity can facilitate species co-occurrence at fine-scales, but environmental data is rarely collected at sufficiently high resolution to test this empirically. While there is emerging evidence that subtle variation in soil hydrology represents a fundamental fine-scale niche axis within plant communities, this is la...
Article
Succession has been a focal point of ecological research for over a century, but thus far has been poorly explored through the lens of modern phylogenetic and trait-based approaches to community assembly. The vast majority of studies conducted to date have comprised static analyses where communities are observed at a single snapshot in time. Long-t...
Article
The International Union for the Conservation of Nature (IUCN) has proposed a standard global assessment protocol for the evaluation of conservation risks to ecosystems. The assessment criteria mirror the IUCN protocol for the assessment of species, however there are relatively few case studies available to demonstrate their utility across a broad r...
Article
Background and aims Seed dormancy enhances fitness by preventing seeds from germinating when the probability of seedling survival and recruitment is low. The onset of physical dormancy is sensitive to humidity during ripening; however, the implications of this mechanism for seed bank dynamics have not been quantified. This study proposes a model th...
Chapter
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Summary Heathlands are major repositories of Australia's unique and iconic flora and also support a specialised fauna. Often situated within spectacular scenic landscapes, heathlands provide an important focus for a growing multi-million dollar ecotourism industry. Heathlands span a remarkably broad range of tropical and temperate climates acros...
Article
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We evaluated the restoration of native plant assemblages by topsoil translocation in the Hunter Valley, south‐east Australia. Species' responses were characterized by defining nine plant functional types (PFTs) based on combinations of four response mechanisms (seed bank persistence, germination cues, resprouting mechanisms, and longevity) through...
Article
Fire regimes, grazing regimes and climatic variation potentially influence the distribution and abundance of plant species in the mallee over long time scales. For example, the timing of fires and rainfall events influences the establishment of many plant species, while herbivory and drought have selective effects on plant survival. Rainfall events...
Article
Models that couple habitat suitability with demographic processes offer a potentially improved approach for estimating spatial distributional shifts and extinction risk under climate change. Applying such an approach to five species of Australian plants with contrasting demographic traits, we show that: (i) predicted climate‐driven changes in range...
Article
2012). Vegetation dynamics in coastal heathlands of the Sydney Basin. Proceedings of the Linnean Society of New South Wales 134, B181-B197. Heathlands are dynamic ecosystems that change in response to fi re regimes and climate variations, as well as endogenous processes such as competition between component species. An understanding of how heathlan...
Article
2012). Population dynamics of Xanthorrhoea resinosa Pers. over two decades: implications for fi re management. Proceedings of the Linnean Society of New South Wales 134, B249-B266. Fire has an important infl uence on the biota of Royal National Park and is a factor over which park managers exert some control. Fire management guidelines for biodiver...
Conference Paper
Background/Question/Methods Arid and semi-arid regions make up a total of 33% of the earth’s landmass and provide a rich diversity of flora and fauna that are well adapted to the harsh environments. Climate change is likely to alter conditions in these regions but the impacts on biodiversity are unclear. Appropriately assessing species’ extinctio...
Article
As the number and intensity of threats to biodiversity increase, there is a critical need to investigate interactions between threats and manage populations accordingly. We ask whether it is possible to reduce the effects of one threat by mitigating another. We used long-term data for the long-lived resprouter, Xanthorrhoea resinosa Pers., to param...
Article
Full-text available
Native vegetation of the NSW south coast, escarpment and southeast tablelands was classified into 191 floristic assemblages at a level of detail appropriate for the discrimination of Threatened Ecological Communities and other vegetation units referred to in government legislation. Assemblages were derived by a numerical analysis of 10832 field sam...
Article
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The establishment of a characteristic assemblage of native species is fundamental to the restoration of natural ecosystems. Species diversity is important in aesthetic terms (restored sites must resemble reference sites) and because restored ecosystems are more likely to be functional, self-sustaining and resilient in the face of periodic environme...
Article
Coastal floodplains are functionally important and highly endangered ecosystems in southeastern Australia, which have a long history of exploitation and environmental modification. In this study, we undertook a systematic survey of contemporary vegetation in two recently established nature reserves on the south coast of New South Wales and investig...
Article
Persistence niches are expected to favour qualitatively different plant life histories compared with regeneration niches. In fire-prone habitats, for example, resprouting plants may be expected to exploit persistence niches, whereas obligate-seeders by definition exploit regeneration niches. Resprouter life histories should be typified by high rate...
Article
Burns conducted to reduce fuels are usually carried out under mild weather conditions. This introduces a risk that soil heating will be insufficient to trigger germination in species with a heat-shock requirement. Resprouting graminoids with leaves or culms arising from subterranean meristems can be used to estimate soil heating because the leaf is...
Article
Overstorey shrub species are known to influence the composition of theunderstorey in Southern Hemisphere heathlands. Overstorey densities aresusceptible to variations in fire frequency; thus, fire regimes may influenceoverstorey/understorey interactions and overall floristic composition. Wecompared patches of Banksia heath which had supported anove...
Conference Paper
Full-text available
Methodologies for estimating the degree of soil heating during a fire are important in allowing predictions of the response of vegetation to fire. We investigated two post-fire indicators that may allow a reliable estimate of the levels of soil heating during a fire and the relevance of these indicators to the response of plants to fire in southeas...
Article
The effect of high frequency fire regimes on a coastal heathland north of Sydney was examined. Plant community composition and species frequency and density (of a subset of species) were compared among sites burnt by either one, two or three fires in the period 1988-1990 inclusive. Constrained ordination indicated that number of fires had a signifi...
Article
Factors influencing the survival of seedlings of the wet mallee-eucalypt Eucalyptus luehmanniana F.Muell. were examined using seedlings germinated in the laboratory and planted into the field. The effects of time since fire (0, 13 and 26 years), predation and position relative to adult canopy on seedling survival and growth in the first year after...

Citations

... Bushfire often has negative impacts on native wildlife (e.g., mammals 34 ), but can have positive effects on invasive species (e.g., cats, foxes 35 ). However, the effects of bushfire on anurans are not well understood, and impacts differ depending on species and life stages. ...
... An especially dangerous bushfire future is projected for Australia's temperate forest regions [1], as warming intensifies the decline of southern Australia's winter rainfall and increases the number of extreme heat events [2]. This combination will drive greater likelihood of intense forest fire conditions [3], with more hot, dry, windy weather, such as recently witnessed during the "Black Summer" of 2019-2020, which resulted in the most extensive forest fires in Australia's recorded history [1,4,5]. These mega-fires pose increasing risks to human life, biodiversity and socioeconomic wellbeing in Australia and other compound/interacting threats to biodiversity, including species composition, plant functional type, habitat and canopy structure, in peri-urban forests of southeast Australia and globally. ...
... This process can be realistic for some RLE measures such as loss in extent over time, i.e., once a given ecosystem type has been converted for intensive land uses, the "collapsed" state is quite apparent. However, for other measures such as environmental degradation, the threshold of ecosystem collapse may only be described qualitatively (e.g., the point where native species composition has been transformed and is no longer "recognizable" as the type originally described in the chosen ecosystem classification [29]). That is, the actual threshold of collapse is generally unknown. ...
... In addition, recent studies have further documented that stalagmites are robust archives of paleo-fire activity (e.g., Nagra et al., 2016;Treble et al., 2016;Bian et al., 2019). Given the more than doubling of extreme seasonal fire weather conditions in CA over the past 4 decades (Goss et al., 2020), there is an opportunity to integrate fire-derived proxies into cave monitoring studies in fire-prone regions. ...
... At more temperate latitudes, researchers have discovered that speleothems can preserve evidence of past wildfires. These combustion events temporarily alter the 18 O and trace element composition of drip water in underlying cavern systems, even for low-severity fires (Treble et al. 2016;Coleborn et al. 2018). This approach may allow speleothems to act as archives for past natural and anthropogenic fires. ...
... Herbivores may concentrate in post-fire regrowth to exploit foraging resources, limiting survival and growth of post-fire seedlings and resprouts (Giljohann et al., 2017;Leigh & Holgate, 1979). They may also degrade ecosystem function by reducing plant biomass and litter and disrupting soil structure (Eldridge et al., 2019), and these effects are likely exacerbated by fire C2. ...
... Similarly, increasing attention has focused on the significance of the role of soil microbiomes in degraded karst ecosystems. Key environmental factors, such as vegetation succession , soil pH (Qi et al., 2018), soil particulate organic matter chemistry (Xiao et al., 2017), soil CO 2 (Coleborn et al., 2016), and rhizosphere exudates (Pan et al., 2016), have often been used to highlight the differences in microbial communities between karst areas and non-karst areas (Fan et al., 2019). The current research has adequately revealed the relationship between plants and soil microorganisms. ...
... In contrast, GAB springs have been subject to extinction and diminishment because of aquifer drawdown since pastoral settlement, and their dependent species of plants and animals have also declined, including numerous local extinctions (Rossini et al. 2018). Numerous palatable trees and shrubs are in decline across the study area (Auld et al. 2015, Tiver and Andrew 1997, although the long-term dynamics of their populations require further research . ...
... Limiting the recruitment and regeneration of long-lived perennials creates a 'time-lag' effect; once the current generation of shrubs dies out, a severe shift in the demography and hence in the structure of the shrub layer will occur (Crisp 1978). Unprecedented changes in the arid zone bird community are anticipated if the ageing generation of long-lived perennial shrubs thins out and dies without recovery (Reid & Fleming 1992;Vesk & Mac Nally 2006;Auld et al. 2015). ...
... Adam et al. (1985), for example, identified a range of tall reedbeds, short grasslands and sedgelands, non-saltmarsh sedgelands, wet meadows, semi-aquatic and aquatic herbfields and open freshwater swamps in their inventory of New South Wales coastal wetlands. In parts of low-lying coastal floodplain along the New South Wales coast, reedbeds give way to meadows dominated by shorter sedges and grasses, including several species of Paspalum, Panicum, Pseudoraphis, Eleocharis and Isolepis, of which Paspalum distichum and Eleocharis equisetina are the most common (Keith and Scott 2005;Keith et al. 2007). These species tend to occupy the brackish backplains between the channels of larger rivers, where they receive periodic overbank flows or sheet flows from lithic slopes adjacent to the floodplain so that tidal influence is diluted, but water tables are retained close to the surface for extended periods (Boon et al. in press). ...