Guttation, a process of natural secretion, is often observed during early morning or in the late hours of the day as liquid drops are exuded from uninjured leaves through special microscopic structures called ‘hydathodes’. Unlike stomata, hydathodes are always open for the liquid to flow out of leaves. The recent botanical, physiological and biotechnological innovations have unravelled its basic and practical utility, which could lead to breakthroughs in new healthcare systems and ease global food-security concerns.
Australian Journal of Botany
Volume 61 Number 7 2013
BT13214Correlated morphological and genetic patterns in Embothrium coccineum (Proteaceae) across climate and geography: can Embothrium survive patagonian climate change?
Covering 20° of latitude in the Patagonian Andes, Embothrium occupies a range of habitats that are moving with climate change. We show that current biotic patterns vary with climate across geography, forecast responses to ongoing climate change, and predict that Embothrium must move, but will persist. Our approach can be used for other species facing similar climatic challenges.
BT13191The carbon and nitrogen cost associated with the growth, reproductive and dormant phases of two South African semi-arid geophytic species of Gethyllis (Amaryllidaceae)
South Africa has a rich floral heritage and the conservation thereof is of international importance. Gethyllis multifolia is threatened and G. villosa not, while both species are occupying the same natural habitat, and it was discovered that G. villosa uses its available natural resources more effectively than does G. multifolia. This data could reveal to the South African floral conservation agencies which factors contribute to the declining numbers of certain species and how this problem should be addressed.
BT13194An apomictic tetraploid Paspalum chaseanum cytotype and its cytogenetic relationship with P. plicatulum (Poaceae): taxonomic and genetic implications
A new apomictic autotetraploid cytotype is reported for Paspalum chaseanum. Interspecific hybridisation between this accession and a sexual tetraploid P. plicatulum plant indicated that both species are closely related and belong to the same subgeneric taxonomic group. Fertility of the hybrids suggested that gene transferring between these two forage grass species is a possibility in breeding programs.
BT12024Eucalypt forests as indicators of the gradients within the central Queensland serpentine landscape of Australia
The vegetation of the central Queensland serpentine landscape displays typical serpentine syndrome of short stature, low species richness and high levels of endemism. We found that the structure of the eucalypt forests could be used as biological indicators of the severity of the serpentine soils. In particular the relative basal area of the overstorey tree Corymbia xanthope correlates to the soil Mg : Ca quotients.
BT13141Population biology of coppicing plants: survival of mallee (Eucalyptus spp.) populations exposed to contrasting fire and cutting regimes
This paper examines data obtained from two experiments running concurrently over an 8-year period designed to investigate the survival of mallee eucalypts exposed to various decapitation treatments applied at contrasting frequencies. Annual autumn decapitation, with or without combined spring decapitation, gave the most rapid rates of depletion.
BT13115Fire does not stimulate flowering of the grasstree Xanthorrhoea latifolia subsp. latifolia in central Queensland
Many southern Australian grasstrees, genus Xanthorrhoea, flower profusely after fire and the genus is often described as fire-dependent, but little is known about the responses to fire by northern Australian species. We found that up to 44% of an unburnt population of Xanthorrhoea latifolia subsp. latifolia in central Queensland flowered every autumn and an experiment showed that fire had no effect on flowering. This emphasises the importance of studying each species so as to formulate effective fire-management guidelines.
BT13217Physical and chemical drivers of vegetation in groundwater-source pools on the Bogong High Plains, Victoria
This is a descriptive study of groundwater-source pools across three catchments on the Bogong High Plains, Victoria (Australia). The most common species of bryophyte identified in the groundwater-source pools was Blindia robusta. The groundwater was found to be deficient in all ionic components. High levels of dissolved CO2 were observed, attributed to organic matter recharge during the aquifer recharge process.