Australian Journal of Botany
Volume 64 Numbers 7 & 8 2016
RESEARCH FRONT: Fire in Australia
The hypothesis that long-term nutrient poverty in Australian soils led to intense fires explains many fire responses of Australian species, as does the near-global evidence for fire during the Cretaceous. The Neogene drying of Australia allowed the rise to dominance of some important components of the extant fire adapted taxa that originated in the Late Cretaceous, but were not prominent in the rainforest-dominated Palaeocene.
BT16109Cretaceous fire in Australia: a review with new geochemical evidence, and relevance to the rise of the angiosperms
Numerous Australian plants show fire-adapted traits that may have evolved in the Cretaceous. Fossil evidence of Cretaceous fires elsewhere on Earth has been much better known than in Australia, but we confirm that Cretaceous fire evidence does occur widely in Australia. Cretaceous burning reasonably influenced the evolution of modern Australian environments, with the most interesting evidence being the success of members of the Proteaceae family, lineages of which were important in burnt, open habitats at least 70 million years ago.
The extrapolation back in time of characters found in living species and populations to their common ancestor suggests that the eucalypts, and possibly the fire-adapted traits that now allow eucalypts to dominate sclerophyll forests and woodlands in Australia, had evolved ~65 million years ago. This is some 12 million years earlier than the oldest known eucalypt fossils. Our paper identifies reasons underlying this discrepancy and suggests ways this might be resolved.
Eucalypts dominate the Australian vegetation today and thrive in a high fire frequency environment. Their macrofossil record suggests they originated in the Weddellian Biogeographic Province, around the Cretaceous–Paleogene boundary, in an area with high natural fire frequency and some dry periods when flammable fuel could accumulate.
BT16165Fire and Late Oligocene to Mid-Miocene peat mega-swamps of south-eastern Australia: a floristic and palaeoclimatic interpretation
The Late Oligocene to Mid-Miocene brown coals of the Gippsland Basin in southern Victoria preserve a rich botanical suite of macro- and microfossils, sometimes associated with fusinite or fossil charcoal remains. Detailed pollen and macrofossil analyses have identified many plant taxa with affinities to modern genera and families that are associated with the charcoal deposits. The palaeobotanical and geological setting for the deposition of these ancient Tertiary peat mega-swamps is outlined against a background influence of fire in a mesothermal climate, with the likelihood of a pronounced seasonal influence.
BT16081A framework for testing the influence of Aboriginal burning on grassy ecosystems in lowland, mesic south–eastern Australia
How Aborigines shaped the Australian environment with fire has been fiercely contested by historians and ecologists. The present paper uses ecological theory, and historic archives to review and test our understanding of the role of Aboriginal burning in temperate grasslands. Fire-stick farming for the production of staple roots was likely instrumental in grassland formation and maintenance, and implies targeted management that affected the structure and function of temperate grassy ecosystems.
The arrival of people did not itself cause large extensive change in fire regimes in Pleistocene Australia. However, people caused megafaunal extinction, and this resulted in dramatic changes to fire and vegetation, but only in some environments.
BTv64n8_ED2Virtual Issue in Australian Journal of Botany: rare and threatened plant conversation and recovery
BT16105Whole-chloroplast analysis as an approach for fine-tuning the preservation of a highly charismatic but critically endangered species, Wollemia nobilis (Araucariaceae)
The critically endangered Wollemi pine is the sole remnant of an ancient lineage with extremely low, and previously undetected, genetic variation. Advanced genomic techniques enabled the detection of genetic diversity at two sites. This information is critical for ex situ preservation of this charismatic species and highlights the simple application of new technologies to biodiversity conservation.
BT16061Ex situ germplasm preservation and plant regeneration of a threatened terrestrial orchid, Caladenia huegelii, through micropropagation and cryopreservation
The spider orchids (Caladenia) of Australia comprise the largest single terrestrial orchid genus, with >300 species, however many are threatened in their natural habitats – including the grand spider orchid (C. huegelii). We report on development of successful tissue culture and cryopreservation protocols for off-site (ex situ) germplasm conservation.
Tree height control is important in the management of macadamia orchards. Hedging the tops of the trees is quick and cheap, but brings with it a large yield penalty. We show that hedging only half the tops of the trees has much less of a yield penalty and restricts the regrowth.
Long-lived seed banks provide the ability for many plants to survive extended periods of drought. The failure of P. spinescens (a key wetland plant in Barmah Forest) to germinate post-drought was found to be implicated with the lack of a viable long-lived seed bank. For this species in this system, regeneration from stem fragments and rootstock may be more important than germination from seeds.
Australia’s native baobab, Adansonia gregorii, is the only baobab tree outside the African continent and is thought to be hawkmoth-pollinated. The aim was to identify major pollinators. The results of the current study show that the tree is mammal-pollinated, with the black flying fox (Pteropus alecto) as the main pollinator.
BT16128High nuclear genetic differentiation, but low chloroplast diversity in a rare species, Aluta quadrata (Myrtaceae), with a disjunct distribution in the Pilbara, Western Australia
The rare Pilbara species Aluta quadrata is found in three geographically separated locations in the Hamersley Range, and a genetic study identified a moderate to high contemporary differentiation among locations, but low historical differentiation. The differences among locations suggest the use of local seed sources for augmentation or establishment of new populations, as may be required to manage impacts from mining operations.
BT15280Photosynthetic and anatomical responses of three plant species at two altitudinal levels in the Neotropical savannah
Three plants from Neotropical savannah were evaluated at two altitudinal areas, separated by 700 m. The leaf anatomy, the quantum yield of photosystem II, and the photosynthetic pigments were taken during the rainy season. High structural modifications and low physiological alterations were apparent, showing that the abiotic factors appear to modulate the plastic responses of plants across altitude.
BT16091Genetic and morphological analysis of multi-stemmed plants of tuart (Eucalyptus gomphocephala)
Investigation of genetic and morphological differentiation in tree and multi-stemmed forms of tuart (Eucalyptus gomphocephala) showed no genetic differentiation associated with growth habit, but there were some morphological differences in buds and fruits. The differences in growth habit in fragmented populations at the northern end of the distribution on the Swan Coastal Plain in Western Australia are likely to be due to environmental factors associated with harsh conditions.
BT12225_COCorrigendum to: New handbook for standardised measurement of plant functional traits worldwide
The peer-reviewed and edited version of record published online before inclusion in an issue
BT16177Shifting from acquisitive to conservative: the effects of Phoradendron affine (Santalaceae) infection in leaf morpho-physiological traits of a Neotropical tree species
As parasitic plants, mistletoes are functionally adapted to use host resources for their own growth and reproduction. As a response to mistletoe infection, infected branches produce leaves with morpho-physiological traits that allow higher resource conservation.
BT16148A genetic, demographic and habitat evaluation of an endangered ephemeral species Xerothamnella herbacea from Australia
Xerothamnella herbacea is an endangered herbaceous species from the Brigalow Belt impacted by gas pipeline developments. Most populations consisted of less than 100 plants with moderate to low genetic diversity and inbred. Geographic proximity does not predict genetic similarity of populations and diversity is not correlated with population size.
The highly toxic species of Ricinus communis L., was investigated for leaf anatomy, histochemistry and composition of secondary metabolites. Leaves of simple structure with numerous idioblasts and strong positive reaction to histochemical reagents for terpenes, flavonoids, phenolics and alkaloids. Among the secondary metabolites detected is the highly toxic alkaloid ricinine.
BT16154Leaf and culm silicification of Pampas grass (Cortaderia selloana) developed on different soils from Pampean region, Argentina
Here we analysed the relation between the accumulation of silica-made particles and environmental and biological factors, a relation scarcely known in pampean grasses. Grasses, along with other plants, produce glass-like particles in their tissues which have multiple functions during plant growth and development. Understanding the factors affecting silica accumulation in plants has implications for managing agroecosystems and Si-requiring crops such as rice.
BT16155Germination ecology of six species of Eucalyptus in shrink–swell vertosols: moisture, seed depth and seed size limit seedling emergence
Six Eucalyptus species with diverse seed sizes were sown in vertosol soils in a glasshouse to investigate the influence of sowing depth and three soil-moisture scenarios on seedling emergence. All species had greater emergence when sown superficially but responded differently to the watering treatments. Seed size had little effect.
BT16125Comparison of two monodominant species in New Caledonia: floristic diversity and ecological strategies of Arillastrum gummiferum (Myrtaceae) and Nothofagus aequilateralis (Nothofagaceae) rainforests
Arillastrum gummiferum (Myrtaceae) and Nothofagus aequilateralis (Nothofagaceae) are two tree species known to dominate the upper canopy of some rainforests on ultramafic substrates in New Caledonia. Structure, diversity and composition of these forests were investigated to better understand the ecological mechanisms leading to their monodominance.
These articles have been peer reviewed and accepted for publication. They are still in production and have not been edited, so may differ from the final published form.
Subtropical native grasslands may not require fire, mowing or grazing to maintain native plant diversity
Temporal vegetation changes in a Seasonally Dry Tropical Forest enclave in an ecotonal region between Brazilâs savanna and semiarid zones
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Australian Journal of Botany 61 (3)N. Pérez-Harguindeguy, S. Díaz, E. Garnier, S. Lavorel, H. Poorter, P. Jaureguiberry, M. S. Bret-Harte, W. K. Cornwell, J. M. Craine, D. E. Gurvich, C. Urcelay, E. J. Veneklaas, P. B. Reich, L. Poorter, I. J. Wright, P. Ray, L. Enrico, J. G. Pausas, A. C. de Vos, N. Buchmann, G. Funes, F. Quétier, J. G. Hodgson, K. Thompson, H. D. Morgan, H. ter Steege, L. Sack, B. Blonder, P. Poschlod, M. V. Vaieretti, G. Conti, A. C. Staver, S. Aquino, J. H. C. Cornelissen
Australian Journal of Botany 51 (4)J. H. C. Cornelissen, S. Lavorel, E. Garnier, S. Díaz, N. Buchmann, D. E. Gurvich, P. B. Reich, H. ter Steege, H. D. Morgan, M. G. A. van der Heijden, J. G. Pausas, H. Poorter
Fire regime and vegetation change in the transition from Aboriginal to European land management in a Tasmanian eucalypt savannaAustralian Journal of Botany 64 (5)Louise M. Romanin, Feli Hopf, Simon G. Haberle, David M. J. S. Bowman
Spinifex–mallee revegetation: implications for restoration after mineral-sands mining in the Murray–Darling BasinAustralian Journal of Botany 64 (6)Ian R. K. Sluiter, Andrew Schweitzer, Ralph Mac Nally
Pollen morphology of the Myrtaceae. Part 1: tribes Eucalypteae, Lophostemoneae, Syncarpieae, Xanthostemoneae and subfamily PsiloxyloideaeAustralian Journal of Botany 60 (3)Andrew H. Thornhill, Geoff S. Hope, Lyn A. Craven, Michael D. Crisp
Australian Journal of Botany 64 (8)M. Byrne, A. Koenders, K. Rogerson, J. Sampson, E. J. B. van Etten
Whole-chloroplast analysis as an approach for fine-tuning the preservation of a highly charismatic but critically endangered species, Wollemia nobilis (Araucariaceae)Australian Journal of Botany 64 (8)Abigail Greenfield, Hannah McPherson, Tony Auld, Sven Delaney, Catherine A. Offord, Marlien van der Merwe, Jia-Yee S. Yap, Maurizio Rossetto
Lost in time and space: re-assessment of conservation status in an arid-zone flora through targeted field surveyAustralian Journal of Botany 62 (8)J. L. Silcock, A. J. Healy, R. J. Fensham
Seed dormancy and germination in different populations of the Argentinan endemic halophyte grass, Sporobolus phleoides (Poaceae: Chloridoideae)Australian Journal of Botany 64 (6)Geraldina Alicia Richard, María Carolina Cerino, José Francisco Pensiero, Juan Marcelo Zabala
Australian Journal of Botany 60 (3)Andrew H. Thornhill, Peter G. Wilson, Jeff Drudge, Matthew D. Barrett, Geoff S. Hope, Lyn A. Craven, Michael D. Crisp
Australian Journal of Botany 64 (6)Ben J. French, Lynda D. Prior, Grant J. Williamson, David M. J. S. Bowman
Moss and vascular epiphyte distributions over host tree and elevation gradients in Australian subtropical rainforestAustralian Journal of Botany 63 (8)Jennifer C. Sanger, James B. Kirkpatrick
Australian Journal of Botany 63 (8)M. M. Holloway-Phillips, H. Huai, A. Cochrane, A. B. Nicotra
Root biomass, root:shoot ratio and belowground carbon stocks in the open savannahs of Roraima, Brazilian AmazoniaAustralian Journal of Botany 60 (5)Reinaldo Imbrozio Barbosa, Jhonson Reginaldo Silva dos Santos, Mariana Souza da Cunha, Tania Pena Pimentel, Philip Martin Fearnside
Australian Journal of Botany 59 (7)Carlos E. González-Orozco, Shawn W. Laffan, Joseph T. Miller
Restoration of eucalypt grassy woodland: effects of experimental interventions on ground-layer vegetationAustralian Journal of Botany 62 (7)S. McIntyre, R. B. Cunningham, C. F. Donnelly, A. D. Manning
Consequences of long- and short-term fragmentation on the genetic diversity and differentiation of a late successional rainforest coniferAustralian Journal of Botany 59 (4)Rohan Mellick, Andrew Lowe, Maurizio Rossetto
Australian Journal of Botany 60 (2)R. P. Skelton, J. J. Midgley, J. M. Nyaga, S. D. Johnson, M. D. Cramer
Correlations between environmental factors, the biomass of exotic annual grasses and the frequency of native perennial grassesAustralian Journal of Botany 54 (7)Tanja I. Lenz, José M. Facelli
Overcoming physical seed dormancy in priority native species for use in arid-zone restoration programsAustralian Journal of Botany 64 (5)Todd E. Erickson, David J. Merritt, Shane R. Turner