Arid land vegetation dynamics after a rare flooding event : influence of fire and grazing
- Authors: Westbrooke, Martin , Florentine, Singarayer , Milberg, Per
- Date: 2005
- Type: Text , Journal article
- Relation: Journal of Arid Environments Vol. 61, no. 2 (Apr 2005), p. 249-260
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- Description: Arid vegetation is subjected to more or less frequent fire, drought, and sporadic flooding events and grazing. Whilst fire, drought and grazing have been the subject of considerable research, little is known of the impact of flooding in arid environments. In this study we examined opportunistically the effects of a flooding event, and its interaction with fire and grazing on moulding arid vegetation in New South Wales, Australia. We assessed vegetation approximately 2 and 5 years after recession of the water in fenced and unfenced plots subjected to different combinations of flooding and fire. Number of species per area dropped from 11.8 to 5.7 per 625 m(2). Vegetation in plots left open to grazing by vertebrates differed from fenced plots, but the amount of variation explained was small compared with flooding and the change over time. The taxa mostly associated with flooding were Eragrostis spp., Pseudognaphalium luteoalbum and the exotic Nicotiana glauca. Major flooding events not only trigger native species' germination and recruitment but may also create an avenue for exotic species to invade. (C) 2004 Elsevier Ltd. All rights reserved.
- Description: C1
- Description: 2003001050
Post-wildfire seedling colonisation patterns in a Eucalyptus delegatemsis (Myrtaceae) windthrow site at Snowy Rover National Park, Victoria
- Authors: Florentine, Singarayer , Westbrooke, Martin , Milberg, Per , Gibson, Matthew
- Date: 2008
- Type: Text , Journal article
- Relation: Australian Forestry Vol. 71, no. 1 (2008), p. 48-53
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- Description: During June 1998, a severe windstorm caused significant damage to a sub-alpine stand of Eucalyptus delegatensis (Myrtaceae) at the Snowy River National Park. In 2002, about 4.5 y after the windstorm, a study documented the effects on E. delegatensis and early understorey succession. In February 2003, wildfire burnt across the windthrow site and we examined the seedling recruitment patterns at windthrow–burn and burn-only sites. Our aim was to document the regeneration of the canopy-dominant E. delegatensis and to confirm that Acacia dealbata is a pioneer species that potentially interferes with or prevents regeneration of E. delegatensis. Permanent transects were established within the windthrow–burn and burn-only sites. The data suggest that the heavily disturbed (mounded) soil at the windthrow site had a strong positive influence on regeneration of both species. By providing favourable growing conditions, the disturbed soil appears to have assisted seedling survival and subsequent growth of the E. delegatensis, despite competition from dense, concurrently established A. dealbata.
- Description: C1
Decade-long response of arid-land mallee vegetation to fire, flooding and grazing in south-eastern Australia
- Authors: Florentine, Singarayer , Milberg, Per , Di Stefano, Julian , Westbrooke, Martin , Graz, Patrick
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Arid Environments Vol. 121, no. October (2015), p. 7-14
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- Description: Australian arid vegetation has evolved within highly variable environments characterised by low rainfall and sporadic fire events. Episodic high rainfall events are a significant factor in plant species recruitment, but their unpredictability makes them difficult to study. We report on the response of vascular plants to a major rainfall event and flood in an arid region of south-eastern Australia. Fire that occurred two months before the flood was incorporated into the study. Paired fenced and unfenced plots were established at control locations and also in areas that had been either flooded, burnt, or flooded and burnt. Objectives were to quantify the long-term effects of fire, flood and vertebrate herbivory, and their interactions, on vegetation composition, plant life forms and species diversity. We found that relative to controls (i) there was a significant effect of flooding on vegetation composition, (ii) changes in life form abundance were driven by flooding and grazing, (iii) there was a strong positive relationship between grazer exclusion and species diversity that was maintained over time and (iv) there was little effect of fire. Understanding the long-term effects of both natural disturbances and vertebrate herbivory will benefit plant conservation in the arid zone. © 2015 Elsevier Ltd.
Potential contributions of the soil seed bank and seed rain for accelerating the restoration of riparian catchments in Australia
- Authors: Florentine, Singarayer , Milberg, Per , Westbrooke, Martin
- Date: 2023
- Type: Text , Journal article
- Relation: Global Ecology and Conservation Vol. 47, no. (2023), p.
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- Description: The quality and quantity of soil seed bank composition can play a key role in secondary succession restoration efforts such as those involved in this study, which concerned the restoration of damaged native sites in riparian environments in Victoria, Australia. The objective of this study of the restoration work was to determine the role played by naturally existing soil seed bank in the success of natural restoration in these restored and unmanaged riparian areas. In this regard, we sampled the soil seed bank, seed rain, seedlings in the field and vegetation cover from three sub catchments defined by restoration attempts which had been conducted (i) < 3 years, (ii) 4–8 years, and (iii) > 9 years previous to sampling. In addition, (iv) in order to provide comparative data, adjacent sites (iv) chosen for future restoration and (v) with remnant vegetation, were also sampled. From samples, a total of 8858 seedlings were recorded from the seed bank and the vegetation survey showed 170 species, with exotic species being more numerous than native. The seed rain (a total of 1422 seeds) was dominated by exotic species at all sites. When comparing the vegetation distribution and the seed rain composition, it was clear that whilst the seed bank was more promising as a comparative recruitment source of native species, there were still too many sites dominated by exotic species to rely on this as a long-term restoration strategy. However, this study indicated that there were significant variations in restoration potential among the sites, suggesting that some careful prior site selection for investment of restoration efforts is an important issue. As a consequence, we have recommended that a detailed understanding of the soil seed bank and seed rain species composition prior to the restoration is essential, since a positive seed bank composition with a significant relative density of native species seeds, will provide an indication of native species’ resilience and their potential for recovery. We therefore believe that the findings of this study will provide valuable information to natural resource management agencies regarding the strategy for prioritisation of restoration sites, which will be more beneficial than randomly selecting sites for habitat restoration. In addition, with successful sector restoration, it is expected that the increasing usefulness of the seed bank will allow further restoration of adjacent areas with time. © 2023 The Authors