Do we know enough about vegetation dynamics to manage fire regimes in central Australia?

Abstract. A terrestrial biosphere model with dynamic vegetation capability, Integrated Biosphere Simulator (IBIS2), coupled to the NCAR Community Atmosphere Model (CAM2) is used to investigate the multiple climate-forest equilibrium states of the climate system. A 1000-year control simulation and another 1000-year land cover change simulation that consisted of global deforestation for 100 years followed by re-growth of forests for the subsequent 900 years were performed. After several centuries of interactive climate-vegetation dynamics, the land cover change simulation converged to essentially the same climate state as the control simulation. However, the climate system takes about a millennium to reach the control forest state. In the absence of deep ocean feedbacks in our model, the millennial time scale for converging to the original climate state is dictated by long time scales of the vegetation dynamics in the northern high latitudes. Our idealized modeling study suggests that the equilibrium state reached after complete global deforestation followed by re-growth of forests is unlikely to be distinguishable from the control climate. The real world, however, could have multiple climate-forest states since our modeling study is unlikely to have represented all the essential ecological processes (e.g. altered fire regimes, seed sources and seedling establishment dynamics) for the re-establishment of major biomes.

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European impact on fire regimes and vegetation dynamics at the steppe-forest ecotone of southern Patagonia

The Holocene ◽

10.1191/0959683603hl647rp ◽

2003 ◽

Vol 13 (4) ◽

pp. 567-579 ◽

Cited By ~ 54

Author(s):

Ulli M. Huber ◽

Vera Markgraf

Keyword(s):

Vegetation Dynamics ◽

Fire Regimes ◽

Southern Patagonia ◽

Forest Ecotone

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Improved simulation of fire–vegetation interactions in the Land surface Processes and eXchanges dynamic global vegetation model (LPX-Mv1)

Geoscientific Model Development ◽

10.5194/gmd-7-2411-2014 ◽

2014 ◽

Vol 7 (5) ◽

pp. 2411-2433 ◽

Cited By ~ 16

Author(s):

D. I. Kelley ◽

S. P. Harrison ◽

I. C. Prentice

Keyword(s):

Land Surface ◽

Fire Regimes ◽

Surface Processes ◽

Bark Thickness ◽

Northern Australia ◽

Decomposition Rates ◽

Vegetation Model ◽

Dynamic Global Vegetation Model ◽

Central Australia ◽

Global Vegetation

Abstract. The Land surface Processes and eXchanges (LPX) model is a fire-enabled dynamic global vegetation model that performs well globally but has problems representing fire regimes and vegetative mix in savannas. Here we focus on improving the fire module. To improve the representation of ignitions, we introduced a reatment of lightning that allows the fraction of ground strikes to vary spatially and seasonally, realistically partitions strike distribution between wet and dry days, and varies the number of dry days with strikes. Fuel availability and moisture content were improved by implementing decomposition rates specific to individual plant functional types and litter classes, and litter drying rates driven by atmospheric water content. To improve water extraction by grasses, we use realistic plant-specific treatments of deep roots. To improve fire responses, we introduced adaptive bark thickness and post-fire resprouting for tropical and temperate broadleaf trees. All improvements are based on extensive analyses of relevant observational data sets. We test model performance for Australia, first evaluating parameterisations separately and then measuring overall behaviour against standard benchmarks. Changes to the lightning parameterisation produce a more realistic simulation of fires in southeastern and central Australia. Implementation of PFT-specific decomposition rates enhances performance in central Australia. Changes in fuel drying improve fire in northern Australia, while changes in rooting depth produce a more realistic simulation of fuel availability and structure in central and northern Australia. The introduction of adaptive bark thickness and resprouting produces more realistic fire regimes in Australian savannas. We also show that the model simulates biomass recovery rates consistent with observations from several different regions of the world characterised by resprouting vegetation. The new model (LPX-Mv1) produces an improved simulation of observed vegetation composition and mean annual burnt area, by 33 and 18% respectively compared to LPX.

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Improved simulation of fire-vegetation interactions in the Land surface Processes and eXchanges dynamic global vegetation model (LPX-Mv1)

Geoscientific Model Development Discussions ◽

10.5194/gmdd-7-931-2014 ◽

2014 ◽

Vol 7 (1) ◽

pp. 931-1000 ◽

Cited By ~ 7

Author(s):

D. I. Kelley ◽

S. P. Harrison ◽

I. C. Prentice

Keyword(s):

Land Surface ◽

Fire Regimes ◽

Surface Processes ◽

Bark Thickness ◽

Northern Australia ◽

Decomposition Rates ◽

Vegetation Model ◽

Dynamic Global Vegetation Model ◽

Central Australia ◽

Global Vegetation

Abstract. The Land surface Processes and eXchanges (LPX) model is a fire-enabled dynamic global vegetation model that performs well globally but has problems representing fire regimes and vegetative mix in savannas. Here we focus on improving the fire module. To improve the representation of ignitions, we introduced a treatment of lightning that allows the fraction of ground strikes to vary spatially and seasonally, realistically partitions strike distribution between wet and dry days, and varies the number of dry-days with strikes. Fuel availability and moisture content were improved by implementing decomposition rates specific to individual plant functional types and litter classes, and litter drying rates driven by atmospheric water content. To improve water extraction by grasses, we use realistic plant-specific treatments of deep roots. To improve fire responses, we introduced adaptive bark thickness and post-fire resprouting for tropical and temperate broadleaf trees. All improvements are based on extensive analyses of relevant observational data sets. We test model performance for Australia, first evaluating parameterisations separately and then measuring overall behaviour against standard benchmarks. Changes to the lightning parameterisation produce a more realistic simulation of fires in southeastern and central Australia. Implementation of PFT-specific decomposition rates enhances performance in central Australia. Changes in fuel drying improve fire in northern Australia, while changes in rooting depth produce a more realistic simulation of fuel availability and structure in central and northern Australia. The introduction of adaptive bark thickness and resprouting produces more realistic fire regimes in savannas, including simulating biomass recovery rates consistent with observations. The new model (LPX-Mv1) improves Australian vegetation composition by 33% and burnt area by 19% compared to LPX.

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Importance of diurnal refugia to a hare-wallaby reintroduction in Western Australia

Wildlife Research ◽

10.1071/wr05088 ◽

2006 ◽

Vol 33 (5) ◽

pp. 355 ◽

Cited By ~ 10

Author(s):

Blair Hardman ◽

Dorian Moro

Keyword(s):

Release Site ◽

Fire Regimes ◽

Suitable Habitat ◽

Shark Bay ◽

Introduced Herbivores ◽

Radio Transmitters ◽

Opposite Sex ◽

Central Australia ◽

In Fire ◽

Cover Up

In an effort to learn more about the potential for reintroduction of hare-wallabies to sites in Australia, 34 captive-bred hare-wallabies were released onto Peron Peninsula within the Shark Bay World Heritage Property in 2001 as part of an experimental reintroduction program. One objective of this experiment was to characterise their behaviour and daytime refugia to identify suitable habitat for future releases. The mala (Lagorchestes hirsutus) and merrnine (Lagostrophus fasciatus) were fitted with radio-transmitters and tracked daily. Merrnine were more faithful to a previously occupied shelter than mala. Mala maintained a solitary daytime habit at all times. Within the study area, mala preferentially sought low-lying vegetation primarily comprising the species Lamarchea hakeifolia, which provided dense cover up to 1 m in height, under which they constructed scrapes. L. hakeifolia was preferred as shelter vegetation instead of Triodia (spinifex) hummocks, despite Triodia hummock habitat being preferred by mala in central Australia. Merrnine occupied taller vegetation with an open understorey to 1.5 m, although the extremity of the understorey remained dense at this height. Individual merrnine sometimes sheltered with conspecifics of the opposite sex. Since both species utilised floristically and structurally variable vegetation, we suggest that they have the ability to cope with vegetation that has been altered by changes in fire regimes and introduced herbivores. This is particularly important for future reintroduction exercises as the results suggest that vegetation characteristics required to support these species, particularly mala, may be variable rather than limited to perceived necessary habitat types in central Australia or on islands. These results should allow future reintroduction projects to consider a wider range of release-site options during their planning phase.

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Fire regime (recency, interval and season) changes the composition of spinifex (Triodia spp.)-dominated desert dunes

Australian Journal of Botany ◽

10.1071/bt06240 ◽

2007 ◽

Vol 55 (7) ◽

pp. 709 ◽

Cited By ~ 27

Author(s):

Boyd R. Wright ◽

Peter J. Clarke

Keyword(s):

Functional Groups ◽

Fire Regime ◽

Woody Species ◽

Fire Regimes ◽

Fire Season ◽

Sand Ridge ◽

Transient Effects ◽

Time Since Fire ◽

Central Australia ◽

Fire Intervals

Between 2000 and 2002, central Australia experienced the largest fire season in three decades when ~500 000 km2 burned. The effects of these and preceding wildfires in the 1980s on spinifex (Triodia spp.) sand-ridge plant communities were examined at 38 sites in central Australia. We used both multivariate and univariate techniques to assess floristic differences among sites of contrasting time-since-fire, fire season and fire interval. Time-since-fire had a consistent floristic influence across the landscape, with increased abundances of ephemeral grasses and forbs and Triodia seedlings, and species richness soon after fire but decreasing long after fire. Fire season had little effect on most functional groups of plants, although seedlings of woody species were significantly more abundant following summer than winter fires. Likewise, recent short fire intervals appeared to have little impact on the population dynamics of most functional groups, although some transient effects were observed on abundances of ephemeral forbs, Triodia seedlings and herbaceous clonal species. Long-term woody species abundances appeared to be affected by short fire intervals in the 1980s when repeated fires seemed to stimulate recruitment of some resprouting species. The present study highlighted the relative stability of spinifex vegetation types in the face of landscape-scale pyric perturbation, but emphasised that localised shifts in the composition and structure of the plant community may occur under certain fire regimes.

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Fire and its management in central Australia

The Rangeland Journal ◽

10.1071/rj07037 ◽

2008 ◽

Vol 30 (1) ◽

pp. 109 ◽

Cited By ~ 40

Author(s):

G. P. Edwards ◽

G. E. Allan ◽

C. Brock ◽

A. Duguid ◽

K. Gabrys ◽

...

Keyword(s):

Land Use ◽

Large Scale ◽

Fire Management ◽

Aboriginal People ◽

Fire Regimes ◽

Management Objectives ◽

Pastoral Production ◽

Fire Exclusion ◽

Central Australia ◽

Large Scale Land

Over the last 130 years, patterns of land use in central Australia have altered dramatically, and so too have fire regimes and fire management objectives. Although Aboriginal people still have tenure over large parts of the landscape, their lifestyles have changed. Most Aboriginal people now live in towns and settlements and, although fire management is still culturally important, the opportunities for getting out on country to burn are constrained. Large parts of the landscape are now used for pastoral production. Under this land use the management objective is often one of fire exclusion. The other large-scale land use is for conservation. Here, fire management has a greater focus on conserving biodiversity using various burning strategies. In this paper we explore contemporary fire regimes in central Australia. Widespread fire events are found to be associated with two or more consecutive years of above-average rainfall. Although most of the fires linked with these high rainfall periods occur during the warmer months, in recent times these fires have exhibited increased activity during the cooler months. There has been a concomitant increase in the number and size of these fires and in the number of fires associated with roads. We also explored current fire management issues on Aboriginal, pastoral and conservation lands. Current fire management goals are not being wholly met on any of these land tenures in central Australia and social conflict sometimes emerges as a result. There are overlaps in management aims, issues and the under-achievement of desired outcomes across the land tenures which lead us to five key recommendations for improving fire management outcomes in central Australia. We finish with some comments on associated opportunities for livelihood enhancement based on the management of fire.

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