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Australian Journal of Botany Australian Journal of Botany Society
Southern hemisphere botanical ecosystems
RESEARCH ARTICLE

Effects of fire frequency and microhabitat on the ground layer in a grassy woodland

Penny J. Watson A and E. Charles Morris https://orcid.org/0000-0002-9427-0612 A B
+ Author Affiliations
- Author Affiliations

A School of Science, Western Sydney University, PO Box 1797, Penrith, NSW 2071, Australia.

B Corresponding author. Email: c.morris@westernsydney.edu.au

Australian Journal of Botany 68(6) 425-438 https://doi.org/10.1071/BT20047
Submitted: 4 May 2020  Accepted: 22 September 2020   Published: 12 November 2020

Abstract

Grassy woodlands worldwide are vertically structured by trees, a ground layer of grasses and forbs, and a variable mid-storey. In Western Sydney’s Cumberland Plain Woodland this mid-storey is increasingly dominated by the prickly shrub Bursaria spinosa Cav. subsp. spinosa. We investigated whether tree and shrub vegetation affects species richness and composition of ground layer microhabitats in this woodland, and whether fire frequency directly affects the ground layer in addition to any indirect effects via overstorey vegetation. Replicate sites were located in areas that had burnt with a frequency that was high, moderate or low. All sites had a similar time since last fire. Three microhabitats (open, under Bursaria, around tree) within each site were sampled for species richness and composition of native and exotic species. Native species richness was not significantly affected by either microhabitat or fire frequency, for total species, grasses or forbs; however the relative abundance of native grasses decreased significantly as fire frequency declined, while the relative abundance of native forbs increased. Exotic species richness was lowest at high fire frequency and significantly higher at low fire frequency. Species composition was significantly affected by both microhabitat and fire frequency combining independently. Planned burning at relatively short intervals can help managers retain grassy habitat for open patch species, habitat for ground layer species that do best under frequent fire, and a robust Themeda triandra Forssk. sward antagonistic to weeds.

Keywords: Bursaria spinosa, CAP analysis, Cumberland Plain Woodland, encroachment, endangered grassy woodlands, fire interval, microhabitats, patch.


References

Anderson MJ, Gorley RN, Clarke KR (2008) ‘PERMANOVA+ for PRIMER: guide to software and statistical methods.’ (PRIMER-E Ltd: Plymouth, UK)

Baker AG, Catterall C, Benkendorff K, Fensham RJ (2020) Rainforest expansion reduces understorey plant diversity and density in open forest of eastern Australia. Austral Ecology
Rainforest expansion reduces understorey plant diversity and density in open forest of eastern Australia.Crossref | GoogleScholarGoogle Scholar |

Belsky AJ, Canham CD (1994) Forest gaps and isolated savanna trees. Bioscience 44, 77–84.
Forest gaps and isolated savanna trees.Crossref | GoogleScholarGoogle Scholar |

Belsky A, Mwonga S, Amundson R, Duxbury J, Ali A (1993) Comparative effects of isolated trees on their undercanopy environments in high- and low-rainfall savannas. Journal of Applied Ecology 30, 143–155.
Comparative effects of isolated trees on their undercanopy environments in high- and low-rainfall savannas.Crossref | GoogleScholarGoogle Scholar |

Benson DH (1992) The natural vegetation of the Penrith 1 : 100 000 map sheet. Cunninghamia 2, 541–596.

Benson EJ, Hartnett DC (2006) The role of seed and vegetative reproduction in plant recruitment and demography in tallgrass prairie. Plant Ecology 187, 163–178.
The role of seed and vegetative reproduction in plant recruitment and demography in tallgrass prairie.Crossref | GoogleScholarGoogle Scholar |

Benson EJ, Hartnett DC, Mann KH (2004) Belowground bud banks and meristem limitation in tallgrass prairie plant populations. American Journal of Botany 91, 416–421.
Belowground bud banks and meristem limitation in tallgrass prairie plant populations.Crossref | GoogleScholarGoogle Scholar | 21653397PubMed |

Birk EM, Bridges RG (1989) Recurrent fires and fuel accumulation in even-aged blackbutt (Eucalyptus pilularis) forests. Forest Ecology and Management 29, 59–79.
Recurrent fires and fuel accumulation in even-aged blackbutt (Eucalyptus pilularis) forests.Crossref | GoogleScholarGoogle Scholar |

Borer ET, Seabloom EW, Gruner DS, et al. (2014) Herbivores and nutrients control grassland plant diversity via light limitation. Nature 508, 517–520.
Herbivores and nutrients control grassland plant diversity via light limitation.Crossref | GoogleScholarGoogle Scholar | 24670649PubMed |

Breshears DD (2006) The grassland-forest continuum: trends in ecosystem properties for woody plant mosaics? Frontiers in Ecology and the Environment 4, 96–104.
The grassland-forest continuum: trends in ecosystem properties for woody plant mosaics?Crossref | GoogleScholarGoogle Scholar |

Cary GJ, Morrison DA (1995) Effects of fire frequency on plant species composition of sandstone communities in the Sydney region: combinations of inter-fire intervals. Australian Journal of Ecology 20, 418–426.
Effects of fire frequency on plant species composition of sandstone communities in the Sydney region: combinations of inter-fire intervals.Crossref | GoogleScholarGoogle Scholar |

Chilcott C, Reid NCH, King K (1997) Impact of trees on the diversity of pasture species and soil biota in grazed landscapes on the Northern Tablelands, NSW. In ‘Conservation outside nature reserves’. (Eds P Hale, D Lamb) pp. 378–386. (Centre for Conservation Biology, University of Queensland: Brisbane, Qld, Australia)

Costello DA, Lunt ID, Williams JE (2000) Effects of invasion by the indigenous shrub Acacia sophorae on plant composition of coastal grasslands in south-eastern Australia. Biological Conservation 96, 113–121.
Effects of invasion by the indigenous shrub Acacia sophorae on plant composition of coastal grasslands in south-eastern Australia.Crossref | GoogleScholarGoogle Scholar |

Dalgleish HJ, Hartnett DC (2009) The effects of fire frequency and grazing on tallgrass prairie productivity and plant composition are mediated through bud bank demography. Herbaceous Plant Ecology 201, 411–420.
The effects of fire frequency and grazing on tallgrass prairie productivity and plant composition are mediated through bud bank demography.Crossref | GoogleScholarGoogle Scholar |

Fitzgerald JK (2009) The soil of abandoned farmland, Cumberland Plain woodland and restored vegetation. PhD thesis, University of Western Sydney, Hawkesbury, NSW, Australia.

French K, Callaghan B, Hill S (2000) Classifying endangered vegetation communities: a case study of Cumberland Plain woodlands. Pacific Conservation Biology 6, 120–129.
Classifying endangered vegetation communities: a case study of Cumberland Plain woodlands.Crossref | GoogleScholarGoogle Scholar |

Fynn RWS, Morris CD, Edwards TJ (2004) Effect of burning and mowing on grass and forb diversity in a long-term grassland experiment. Applied Vegetation Science 7, 1–10.
Effect of burning and mowing on grass and forb diversity in a long-term grassland experiment.Crossref | GoogleScholarGoogle Scholar |

Gibbs L, Reid N, Whalley RDB (1999) Relationships between tree cover and grass dominance in a grazed temperate stringybark (Eucalyptus laevopinea) open-forest. Australian Journal of Botany 47, 49–60.
Relationships between tree cover and grass dominance in a grazed temperate stringybark (Eucalyptus laevopinea) open-forest.Crossref | GoogleScholarGoogle Scholar |

Gleadow RM, Ashton DH (1981) Invasion by Pittosporum undulatum of the forests of central Victoria. I. Invasion patterns and plant morphology. Australian Journal of Botany 29, 705–720.
Invasion by Pittosporum undulatum of the forests of central Victoria. I. Invasion patterns and plant morphology.Crossref | GoogleScholarGoogle Scholar |

Gott B (2004) The role of indigenous fire regimes in guiding bushfire management today. In ‘Bushfire in a changing environment: new directions in management’. (Eds A Baker, M Sparks, B Diekman, S Edmonson, M Misdale, A Hillier, R. Wells) pp. 123–128. (Conference Proceedings, Nature Conservation Council of NSW: Sydney, Australia)

Grace JB, Anderson TM, Seabloom EW, 23 others (2016) Integrative modelling reveals mechanisms linking productivity and plant species richness. Nature 529, 390–393.
Integrative modelling reveals mechanisms linking productivity and plant species richness.Crossref | GoogleScholarGoogle Scholar | 26760203PubMed |

Hastwell GT, Morris EC (2013) Structural features of fragmented woodland communities affect leaf litter decomposition rates. Basic and Applied Ecology 14, 298–308.
Structural features of fragmented woodland communities affect leaf litter decomposition rates.Crossref | GoogleScholarGoogle Scholar |

Hunter JT (2003) Persistence on inselbergs: the role of obligate seeders and resprouters. Journal of Biogeography 30, 497–510.
Persistence on inselbergs: the role of obligate seeders and resprouters.Crossref | GoogleScholarGoogle Scholar |

Keith D (2004) ‘Ocean shores to desert dunes: the native vegetation of New South Wales and the ACT.’ (Department of Environment and Conservation NSW: Hurstville, NSW, Australia)

Kenny B, Sutherland E, Tasker E, Bradstock R (2003) ‘Guidelines for ecologically sustainable fire management.’ (NSW National Parks and Wildlife Service: Hurstville, NSW, Australia)

Knapp AK, Smith MD, Collins SL, Zambatis N, Peel M, Emery S, Wojdak J, Horner-Devine MC, Biggs H, Kruger J, Andleman SJ (2004) Generality in ecology: testing North American grassland rules in South African savannas. Frontiers in Ecology and the Environment 2, 483–491.
Generality in ecology: testing North American grassland rules in South African savannas.Crossref | GoogleScholarGoogle Scholar |

Lewis T, Reif M, Prendergast E, Tran C (2012) The effect of long-term repeated burning and fire exclusion on above- and below-ground Blackbutt (Eucalyptus pilularis) forest vegetation assemblages. Austral Ecology 37, 767–778.
The effect of long-term repeated burning and fire exclusion on above- and below-ground Blackbutt (Eucalyptus pilularis) forest vegetation assemblages.Crossref | GoogleScholarGoogle Scholar |

Lunt ID (1990) Impact of an autumn fire on a long-grazed Themeda triandra (kangaroo grass) grassland: implications for management of invaded, remnant vegetations. Victorian Naturalist 107, 45–51.

Lunt ID (1997) Effects of long-term vegetation management on remnant grassy forests and anthropogenic native grasslands in south-eastern Australia. Biological Conservation 81, 287–297.
Effects of long-term vegetation management on remnant grassy forests and anthropogenic native grasslands in south-eastern Australia.Crossref | GoogleScholarGoogle Scholar |

Lunt ID, Morgan JW (1999) Effect of fire frequency on plant composition at the Laverton North Grassland Reserve, Victoria. Victorian Naturalist 116, 84–89.

Magcale-Macandog DB, Whalley RDB (1994) Factors affecting the distribution and abundance of Microlaena stipoides (Labill.) R.Br. on the Northern Tablelands of New South Wales. The Rangeland Journal 16, 26–38.
Factors affecting the distribution and abundance of Microlaena stipoides (Labill.) R.Br. on the Northern Tablelands of New South Wales.Crossref | GoogleScholarGoogle Scholar |

Morgan JW (1996) Secondary juvenile period and community recovery following late-spring burning of a kangaroo grass Themeda triandra grassland. Victorian Naturalist 113, 47–57.

Morgan JW (1998a) Patterns of invasion of an urban remnant of a species-rich grassland in southeastern Australia by non-native plant species. Journal of Vegetation Science 9, 181–190.
Patterns of invasion of an urban remnant of a species-rich grassland in southeastern Australia by non-native plant species.Crossref | GoogleScholarGoogle Scholar |

Morgan JW (1998b) Importance of canopy gaps for recruitment of some forbs in Themeda triandra-dominated grasslands in south-eastern Australia. Australian Journal of Botany 46, 609–627.
Importance of canopy gaps for recruitment of some forbs in Themeda triandra-dominated grasslands in south-eastern Australia.Crossref | GoogleScholarGoogle Scholar |

Morgan JW (1998c) Composition and seasonal flux of the soil seed bank of species-rich Themeda triandra grasslands in relation to burning history. Journal of Vegetation Science 9, 145–156.
Composition and seasonal flux of the soil seed bank of species-rich Themeda triandra grasslands in relation to burning history.Crossref | GoogleScholarGoogle Scholar |

Morgan JW (2015) Biomass management in native grasslands. In ‘Land of sweeping plains’. (Eds NSG Williams, A Marshall, JW Morgan) pp. 201–222. (CSIRO Publishing: Melbourne, Vic., Australia)

Morgan JW, Lunt ID (1999) Effects of time-since-fire on the tussock dynamics of a dominant grass (Themeda triandra) in a temperate Australian grassland. Biological Conservation 88, 379–386.
Effects of time-since-fire on the tussock dynamics of a dominant grass (Themeda triandra) in a temperate Australian grassland.Crossref | GoogleScholarGoogle Scholar |

Morgan JW, Williams NSG (2015) The ecology and dynamics of temperate native grasslands in south-eastern Australia. In ‘Land of sweeping plains’. (Eds NSG Williams, A Marshall, JW Morgan) pp. 61–86. (CSIRO Publishing: Melbourne, Vic., Australia)

Morris EC, Watson PJ (2020) Fire frequency effects in a grassy woodland: trees and grasses. Austral Ecology
Fire frequency effects in a grassy woodland: trees and grasses.Crossref | GoogleScholarGoogle Scholar |

Morris EC, de Barse M, Sanders J (2016) Effect of burning and rainfall on former agricultural land with remnant woodland flora. Austral Ecology 41, 74–86.
Effect of burning and rainfall on former agricultural land with remnant woodland flora.Crossref | GoogleScholarGoogle Scholar |

Morrison DA, Cary GJ, Pengelly SM, Ross DG, Mullins BJ, Thomas CR, Anderson TS (1995a) Effects of fire frequency on plant species composition of sandstone communities in the Sydney region: inter-fire interval and time-since-fire. Australian Journal of Ecology 20, 239–247.
Effects of fire frequency on plant species composition of sandstone communities in the Sydney region: inter-fire interval and time-since-fire.Crossref | GoogleScholarGoogle Scholar |

Morrison DA, LeBrocque AF, Clarke PJ (1995b) An assessment of some improved techniques for estimating the abundance (frequency) of sedentary organisms. Vegetatio 120, 131–145.
An assessment of some improved techniques for estimating the abundance (frequency) of sedentary organisms.Crossref | GoogleScholarGoogle Scholar |

Nichols PBW, Morris EC, Keith DA (2010) Testing a facilitation model for ecosystem restoration: does tree planting restore ground layer species in a grassy woodland? Austral Ecology 35, 888–897.
Testing a facilitation model for ecosystem restoration: does tree planting restore ground layer species in a grassy woodland?Crossref | GoogleScholarGoogle Scholar |

Nieuwenhuis A (1987) The effect of fire frequency on the sclerophyll vegetation of the West Head, New South Wales. Australian Journal of Ecology 12, 373–385.
The effect of fire frequency on the sclerophyll vegetation of the West Head, New South Wales.Crossref | GoogleScholarGoogle Scholar |

Office of Environment and Heritage (2010) ‘NSW Flora fire response database. Ver. 2.0.’ (Fire Ecology Unit, Office of Environment and Heritage: Hurstville, NSW, Australia)

Outhred RK (1984) Semi-quantitative sampling in vegetation survey. In ‘Survey methods for nature conservation’. (Eds K Myers, CR Margules, I Musto) pp. 87–100. (CSIRO: Canberra, ACT, Australia)

Price JN, Morgan JW (2008) Woody plant encroachment reduces species richness of herb-rich woodlands in southern Australia. Austral Ecology 33, 278–289.
Woody plant encroachment reduces species richness of herb-rich woodlands in southern Australia.Crossref | GoogleScholarGoogle Scholar |

Price JN, Good MK, Schutlz NL, Guja LK, Morgan JW (2019) Multivariate drivers of diversity in temperate Australian native grasslands. Australian Journal of Botany 67, 367–380.
Multivariate drivers of diversity in temperate Australian native grasslands.Crossref | GoogleScholarGoogle Scholar |

Prober SM, Lunt ID (2009) Restoration of Themeda australis swards suppresses soil nitrate and enhances ecological resistance to invasion by exotic annuals. Biological Invasions 11, 171–181.
Restoration of Themeda australis swards suppresses soil nitrate and enhances ecological resistance to invasion by exotic annuals.Crossref | GoogleScholarGoogle Scholar |

Prober SM, Thiele KR (2005) Restoring Australia’s temperate grasslands and grassy woodlands: integrating function and diversity. Ecological Management & Restoration 6, 16–27.
Restoring Australia’s temperate grasslands and grassy woodlands: integrating function and diversity.Crossref | GoogleScholarGoogle Scholar |

Prober SM, Lunt ID, Thiele KR (2002a) Determining reference conditions for management and restoration of temperate grassy woodlands: relationships among trees, topsoils and understorey flora in little-grazed remnants. Australian Journal of Botany 50, 687–697.
Determining reference conditions for management and restoration of temperate grassy woodlands: relationships among trees, topsoils and understorey flora in little-grazed remnants.Crossref | GoogleScholarGoogle Scholar |

Prober SM, Thiele KR, Lunt ID (2002b) Identifying ecological barriers to restoration in temperate grassy woodlands: soil changes associated with different degradation states. Australian Journal of Botany 50, 699–712.
Identifying ecological barriers to restoration in temperate grassy woodlands: soil changes associated with different degradation states.Crossref | GoogleScholarGoogle Scholar |

Prober SM, Thiele KR, Lunt ID, Koen TB (2005) Restoring ecological function in temperate grassy woodlands: manipulating soil nutrients, exotic annuals and native perennial grasses through carbon supplements and spring burns. Journal of Applied Ecology 42, 1073–1085.
Restoring ecological function in temperate grassy woodlands: manipulating soil nutrients, exotic annuals and native perennial grasses through carbon supplements and spring burns.Crossref | GoogleScholarGoogle Scholar |

Prober SM, Thiele KR, Lunt ID (2007) Fire frequency regulates tussock grass composition, structure and resilience in endangered temperate woodlands. Austral Ecology 32, 808–824.
Fire frequency regulates tussock grass composition, structure and resilience in endangered temperate woodlands.Crossref | GoogleScholarGoogle Scholar |

Prober S, Taylor S, Edwards R, Mills B (2009) Effectiveness of repeated autumn and spring fires for understorey restoration in weed‐invaded temperate eucalypt woodlands. Applied Vegetation Science 12, 440–450.
Effectiveness of repeated autumn and spring fires for understorey restoration in weed‐invaded temperate eucalypt woodlands.Crossref | GoogleScholarGoogle Scholar |

Prober SM, Thiele KR, Speijers J (2013) Management legacies shape decadal-scale responses of plant diversity to experimental disturbance regimes in fragmented grassy woodlands. Journal of Applied Ecology 50, 376–386.
Management legacies shape decadal-scale responses of plant diversity to experimental disturbance regimes in fragmented grassy woodlands.Crossref | GoogleScholarGoogle Scholar |

Prober SM, Gosper CR, Gilfedder L, Harwood TD, Thiele KR, Williams KJ, Yates CJ (2017) Temperate eucalypt woodlands. In ‘Australian vegetation’. 3rd edn. (Ed. D Keith) pp. 410–437. (Cambridge University Press: Melbourne, Vic., Australia)

Rhoades CC (1996) Single-tree influences on soil properties in agroforestry: lessons from natural forest and savanna ecosystems. Agroforestry Systems 35, 71–94.
Single-tree influences on soil properties in agroforestry: lessons from natural forest and savanna ecosystems.Crossref | GoogleScholarGoogle Scholar |

Richards AE, Brackin R, Lindsay DAJ, Schmidt S (2012) Effect of fire and tree-grass patches on soil nitrogen in Australian tropical savannas. Austral Ecology 37, 668–677.
Effect of fire and tree-grass patches on soil nitrogen in Australian tropical savannas.Crossref | GoogleScholarGoogle Scholar |

Robertson D (1985) Interrelations between kangaroos, fire and vegetation dynamics at Gellibrand Hill Park, Victoria. PhD thesis, University of Melbourne, Parkville, Vic., Australia.

Stuwe J, Parsons RF (1977) Themeda australis grasslands on the basalt plains, Victoria: floristics and management effects. Australian Journal of Ecology 2, 467–476.
Themeda australis grasslands on the basalt plains, Victoria: floristics and management effects.Crossref | GoogleScholarGoogle Scholar |

Tozer M (2003) The native vegetation of the Cumberland Plain, western Sydney: systematic classification and field identification of communities. Cunninghamia 8, 1–75.

Tozer MG, Leishmann MR, Auld TD (2015) Ecosystem risk assessment for Cumberland Plain woodland, New South Wales, Australia. Austral Ecology 40, 400–410.
Ecosystem risk assessment for Cumberland Plain woodland, New South Wales, Australia.Crossref | GoogleScholarGoogle Scholar |

Tremont RM, McIntyre S (1994) Natural grassy vegetation and native forbs in temperate Australia: structure, dynamics and life histories. Australian Journal of Botany 42, 641–658.
Natural grassy vegetation and native forbs in temperate Australia: structure, dynamics and life histories.Crossref | GoogleScholarGoogle Scholar |

Uys RG, Bond WJ, Everson TM (2004) The effect of different fire regimes on plant diversity in southern African grasslands. Biological Conservation 118, 489–499.
The effect of different fire regimes on plant diversity in southern African grasslands.Crossref | GoogleScholarGoogle Scholar |

Vetaas OR (1992) Micro-site effects of trees and shrubs in dry savannas. Journal of Vegetation Science 3, 337–344.
Micro-site effects of trees and shrubs in dry savannas.Crossref | GoogleScholarGoogle Scholar | 33171387PubMed |

Watson PJ, Bradstock RA, Morris EC (2009) Fire frequency influences composition and structure of the shrub layer in an Australian subcoastal temperate grassy woodland. Austral Ecology 34, 218–232.
Fire frequency influences composition and structure of the shrub layer in an Australian subcoastal temperate grassy woodland.Crossref | GoogleScholarGoogle Scholar |

Wilson B (2002) Influence of scattered paddock trees on surface soil properties: a study of the Northern Tablelands of NSW. Ecological Management & Restoration 3, 211–219.
Influence of scattered paddock trees on surface soil properties: a study of the Northern Tablelands of NSW.Crossref | GoogleScholarGoogle Scholar |

Woinarski JCZ, Risler J, Kean L (2004) Response of vegetation and vertebrate fauna to 23 years of fire exclusion in a tropical Eucalyptus open forest, Northern Territory, Australia. Austral Ecology 29, 156–176.
Response of vegetation and vertebrate fauna to 23 years of fire exclusion in a tropical Eucalyptus open forest, Northern Territory, Australia.Crossref | GoogleScholarGoogle Scholar |