Seed viability of early maturing alpine ash (Eucalyptus delegatensis subsp. delegatensis) in the Australian Alps, south-eastern Australia, and its implications for management under changing fire regimes

2017 ◽  
Vol 65 (7) ◽  
pp. 517 ◽  
Author(s):  
Michael D. Doherty ◽  
A. Malcolm Gill ◽  
Geoffrey J. Cary ◽  
Mike P. Austin

Eucalyptus delegatensis R.T. Baker subsp. delegatensis is an interval-sensitive, fire-killed eucalypt that dominates large tracts of montane forest in the Australian Alps. Although it has been widely accepted in forest management that E. delegatensis takes 20 years to flower and fruit after stand-replacing fire events, recent observations after high intensity fires in the Australian Alps have shown that early flowering and fruiting is occurring from what can be termed ‘precocious’ individuals in some areas. In some instances, early flowering and fruit set is occurring within 6 years after stand-replacing fire. One historical study in the Australian Capital Territory had noted that such seed was viable, but we found no reported experiments documenting this or detailing the degree of viability. Here we discuss the results of a germination experiment undertaken on seed collected from Namadgi National Park from early-maturing alpine ash trees. Although at the low end of known viability estimates for E. delegatensis, seed from these individuals was nonetheless found to be viable, with a mean of 455 (s.d. = 139) germinants per 10 g of chaff and seed mix. We discuss this result in relation to fire management in the Australian Alps and suggest further research that needs to be undertaken to better document and understand the phenomenon.


2021 ◽  
Author(s):  
Giovanni Di Virgilio ◽  
Jason P. Evans ◽  
Alejandro Di Luca ◽  
Michael R. Grose ◽  
Vanessa Round ◽  
...  

<p>Coarse resolution global climate models (GCM) cannot resolve fine-scale drivers of regional climate, which is the scale where climate adaptation decisions are made. Regional climate models (RCMs) generate high-resolution projections by dynamically downscaling GCM outputs. However, evidence of where and when downscaling provides new information about both the current climate (added value, AV) and projected climate change signals, relative to driving data, is lacking. Seasons and locations where CORDEX-Australasia ERA-Interim and GCM-driven RCMs show AV for mean and extreme precipitation and temperature are identified. A new concept is introduced, ‘realised added value’, that identifies where and when RCMs simultaneously add value in the present climate and project a different climate change signal, thus suggesting plausible improvements in future climate projections by RCMs. ERA-Interim-driven RCMs add value to the simulation of summer-time mean precipitation, especially over northern and eastern Australia. GCM-driven RCMs show AV for precipitation over complex orography in south-eastern Australia during winter and widespread AV for mean and extreme minimum temperature during both seasons, especially over coastal and high-altitude areas. RCM projections of decreased winter rainfall over the Australian Alps and decreased summer rainfall over northern Australia are collocated with notable realised added value. Realised added value averaged across models, variables, seasons and statistics is evident across the majority of Australia and shows where plausible improvements in future climate projections are conferred by RCMs. This assessment of varying RCM capabilities to provide realised added value to GCM projections can be applied globally to inform climate adaptation and model development.</p>



2011 ◽  
Vol 59 (1) ◽  
pp. 70 ◽  
Author(s):  
Sapphire J. M. McMullan-Fisher ◽  
Tom W. May ◽  
Richard M. Robinson ◽  
Tina L. Bell ◽  
Teresa Lebel ◽  
...  

Fungi are essential components of all ecosystems in roles including symbiotic partners, decomposers and nutrient cyclers and as a source of food for vertebrates and invertebrates. Fire changes the environment in which fungi live by affecting soil structure, nutrient availability, organic and inorganic substrates and other biotic components with which fungi interact, particularly mycophagous animals. We review the literature on fire and fungi in Australia, collating studies that include sites with different time since fire or different fire regimes. The studies used a variety of methods for survey and identification of fungi and focussed on different groups of fungi, with an emphasis on fruit-bodies of epigeal macrofungi and a lack of studies on microfungi in soil or plant tissues. There was a lack of replication of fire treatment effects in some studies. Nevertheless, most studies reported some consequence of fire on the fungal community. Studies on fire and fungi were concentrated in eucalypt forest in south-west and south-eastern Australia, and were lacking for ecosystems such as grasslands and tropical savannahs. The effects of fire on fungi are highly variable and depend on factors such as soil and vegetation type and variation in fire intensity and history, including the length of time between fires. There is a post-fire flush of fruit-bodies of pyrophilous macrofungi, but there are also fungi that prefer long unburnt vegetation. The few studies that tested the effect of fire regimes in relation to the intervals between burns did not yield consistent results. The functional roles of fungi in ecosystems and the interactions of fire with these functions are explained and discussed. Responses of fungi to fire are reviewed for each fungal trophic group, and also in relation to interactions between fungi and vertebrates and invertebrates. Recommendations are made to include monitoring of fungi in large-scale fire management research programs and to integrate the use of morphological and molecular methods of identification. Preliminary results suggest that fire mosaics promote heterogeneity in the fungal community. Management of substrates could assist in preserving fungal diversity in the absence of specific information on fungi.



2021 ◽  
Vol 9 ◽  
Author(s):  
Michael F. Clarke ◽  
Luke T. Kelly ◽  
Sarah C. Avitabile ◽  
Joe Benshemesh ◽  
Kate E. Callister ◽  
...  

Fire shapes ecosystems globally, including semi-arid ecosystems. In Australia, semi-arid ‘mallee’ ecosystems occur primarily across the southern part of the continent, forming an interface between the arid interior and temperate south. Mallee vegetation is characterized by short, multi-stemmed eucalypts that grow from a basal lignotuber. Fire shapes the structure and functioning of mallee ecosystems. Using the Murray Mallee region in south-eastern Australia as a case study, we examine the characteristics and role of fire, the consequences for biota, and the interaction of fire with other drivers. Wildfires in mallee ecosystems typically are large (1000s ha), burn with high severity, commonly cause top-kill of eucalypts, and create coarse-grained mosaics at a regional scale. Wildfires can occur in late spring and summer in both dry and wet years. Recovery of plant and animal communities is predictable and slow, with regeneration of eucalypts and many habitat components extending over decades. Time since the last fire strongly influences the distribution and abundance of many species and the structure of plant and animal communities. Animal species display a discrete set of generalized responses to time since fire. Systematic field studies and modeling are beginning to reveal how spatial variation in fire regimes (‘pyrodiversity’) at different scales shapes biodiversity. Pyrodiversity includes variation in the extent of post-fire habitats, the diversity of post-fire age-classes and their configuration. At regional scales, a desirable mix of fire histories for biodiversity conservation includes a combination of early, mid and late post-fire age-classes, weighted toward later seral stages that provide critical habitat for threatened species. Biodiversity is also influenced by interactions between fire and other drivers, including land clearing, rainfall, herbivory and predation. Extensive clearing for agriculture has altered the nature and impact of fire, and facilitated invasion by pest species that modify fuels, fire regimes and post-fire recovery. Given the natural and anthropogenic drivers of fire and the consequences of their interactions, we highlight opportunities for conserving mallee ecosystems. These include learning from and fostering Indigenous knowledge of fire, implementing actions that consider synergies between fire and other processes, and strategic monitoring of fire, biodiversity and other drivers to guide place-based, adaptive management under climate change.



2003 ◽  
Vol 12 (4) ◽  
pp. 309 ◽  
Author(s):  
Robert E. Keane ◽  
Geoffrey J. Cary ◽  
Russell Parsons

Spatial depictions of fire regimes are indispensable to fire management because they portray important characteristics of wildland fire, such as severity, intensity, and pattern, across a landscape that serves as important reference for future treatment activities. However, spatially explicit fire regime maps are difficult and costly to create requiring extensive expertise in fire history sampling, multivariate statistics, remotely sensed image classification, fire behaviour and effects, fuel dynamics, landscape ecology, simulation modelling, and geographical information systems (GIS). This paper first compares three common strategies for predicting fire regimes (classification, empirical, and simulation) using a 51�000�ha landscape in the Selway-Bitterroot Wilderness Area of Montana, USA. Simulation modelling is identified as the best overall strategy with respect to developing temporally deep spatial fire patterns, but it has limitations. To illustrate these problems, we performed three simulation experiments using the LANDSUM spatial model to determine the relative importance of (1) simulation time span; (2) fire frequency parameters; and (3) fire size parameters on the simulation of landscape fire return interval. The model used to simulate fire regimes is also very important, so we compared two spatially explicit landscape fire succession models (LANDSUM and FIRESCAPE) to demonstrate differences between model predictions and limitations of each on a neutral landscape. FIRESCAPE was developed for simulating fire regimes in eucalypt forests of south-eastern Australia. Finally, challenges for future simulation and fire regime research are presented including field data, scale, fire regime variability, map obsolescence, and classification resolution.



Soil Research ◽  
1971 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
PH Walker ◽  
AB Costin

Reddish dust, transported by strong winds from the dry central regions of Australia, is periodically deposited in the humid eastern part of the continent. Dust sampled in snow on the Australian alps during 1968 is comparable in amount with accession reported earlier in the 1900's in New Zealand and Melbourne. The dust reported here has a median diameter of 4 pm, relatively high organic content, and mineralogy in the less than 2 pm fraction dominated by illite and kaolin. The rate of dust accession during the past was probably sufficient to have modified alpine soils. In particular, snow patch soils have a particle size and mineralogy consistent with dust enrichment. A much lower rate of dust accession seems to occur at present in Canberra on the Southern Tablelands.



2008 ◽  
Vol 17 (6) ◽  
pp. 809 ◽  
Author(s):  
Ross A. Bradstock

Large fires coincident with drought occurred in south-eastern Australia during 2001–2007. Perceptions of large, intense fires as being ecologically ‘disastrous’ are common. These are summarised by four hypotheses characterising large fires as: (i) homogenous in extent and intensity; (ii) causing large-scale extinction due to perceived lack of survival and regeneration capacity among biota; (iii) degrading due to erosion and related edaphic effects; (iv) unnatural, as a consequence of contemporary land management. These hypotheses are examined using available evidence and shown to inadequately account for effects of large fires on biodiversity. Large fires do not burn homogeneously, though they may produce intensely burnt patches and areas. The bulk of biota are resilient through a variety of in situ persistence mechanisms that are reinforced by landscape factors. Severe erosive episodes following fire tend to be local and uncertain rather than global and inevitable. Redistribution of soil and nutrients may reinforce habitat variation in some cases. Signals of fire are highly variable over prehistoric and historic eras, and, in some cases, contemporary and pre-European signal levels are equivalent. The most important effects of large fires in these diverse ecological communities and landscapes stem from their recurrence rate. Adaptive management of fire regimes rather than fire events is required, based on an understanding of risks posed by particular regimes to biota.



2013 ◽  
Vol 22 (7) ◽  
pp. 947 ◽  
Author(s):  
Katrin Lowe ◽  
J. Guy Castley ◽  
Jean-Marc Hero

Fire has varying effects on species ecology. Knowledge of amphibian responses to fire is particularly limited, with variable responses reported amongst studies. Variability is attributed to differences in fire regimes, sampling methodologies, historical exposure to fire and species traits. Acid frogs, a group of amphibians restricted to acidic coastal heath wetlands of eastern Australia, occupy a discrete ecological niche that is exposed to regular and intense fires. Visual encounter surveys conducted monthly over 2 years revealed different short- and long-term responses to fire in three threatened acid frog species (Litoria olongburensis, Litoria freycineti and Crinia tinnula). Fires altered the thermal properties of habitats by increasing substrate temperature and widening daily temperature ranges. Acid frog populations did not suffer adversely from moderate intensity fires as suitable refuges, including standing water, were available. All species were present shortly after fire with subsequent successful reproduction occurring once wetlands were sufficiently inundated. Time since fire was a strong predictor of landscape scale differences in average relative abundance of acid frogs, yet the relationships varied among species. This highlights the importance of assessing community-wide responses to fire at the landscape scale. The dynamic and adaptive responses observed within acid frog populations demonstrate substantial resilience to fire processes in these fire prone environments.



2005 ◽  
Vol 53 (5) ◽  
pp. 445 ◽  
Author(s):  
S. Clarke ◽  
K. French

Grasses form an important component of grassy woodlands, although their response to fire has been understudied. In this study, fire germination responses of 22 Poaceae species from an endangered grassy-woodland community in eastern Australia were investigated. Seeds of 20 native and two exotic species were subjected to heat (no heat, 40, 80 and 120°C) and smoke treatment (10% dilution smoke water) and the percentage germination was compared. Germination response of species showed no consistent pattern to phylogeny and was highly variable. Germination in six species was unaffected by the application of heat or smoke. In five species, heat, irrespective of smoke application, influenced germination. Smoke, irrespective of heat treatment, influenced six species. For a further six species, the effect of smoke varied with temperature. These results suggest that fire regimes will influence the recruitment of grass species differentially and maintaining regional species richness is likely to require the maintenance of a heterogeneous fire regime across the landscape.



2014 ◽  
Vol 40 (2) ◽  
pp. 170-177 ◽  
Author(s):  
Sarsha Gorissen ◽  
Jacqueline Mallinson ◽  
Matthew Greenlees ◽  
Richard Shine


2012 ◽  
Vol 21 (3) ◽  
pp. 197 ◽  
Author(s):  
Lucy G. Halliday ◽  
J. Guy Castley ◽  
James A. Fitzsimons ◽  
Cuong Tran ◽  
Jan Warnken

Fire is an important natural disturbance process within the Australian landscape, but the complex and hazardous nature of fire creates a conservation management dilemma. For landholders of private conservation lands, management for conservation of biodiversity and risk reduction is complicated. Private conservation landholders in eastern Australia directed far less effort towards fire management than other conservation management actions, despite clearly acknowledging the risk and associated responsibilities of fire management on their lands. Nonetheless, landholders did undertake actions to reduce fuel hazards and prepare for wildfire events on their land. Despite the established role and benefits of fire to many ecosystems in the region, landholder understanding of the ecological role of fire was generally poor. Few landholders were aware of ecologically appropriate fire regimes for the vegetation types on their property, and few undertook fire management actions to achieve ecological outcomes. Site-specific obstacles, lack of fire management knowledge and experience, and legal and containment concerns contributed to the low level of fire management observed. There is a need for property-specific fire management planning across all private conservation lands, to further integrate ecological fire requirements into biodiversity management, and prioritise actions that aim to improve conservation outcomes while safeguarding life and property.



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