Features of Coning and Foliar Phenology, Size Classes, and Insect Associates of Cycas armstrongii (Cycadaceae) in the Northern Territory, Australia

1992 ◽  
Vol 119 (1) ◽  
pp. 39 ◽  
Author(s):  
Robert Ornduff
1997 ◽  
Vol 45 (5) ◽  
pp. 893 ◽  
Author(s):  
D. M. J. S. Bowman

A study of the size-class distributions of the Australian boab, Adansonia gibbosa (A.Cunn.) Guymer ex D.Baum, a tree endemic to north-western Australia, was conducted in Gregory National Park and Keep River National Park, in the Northern Territory. It was found that populations of A. gibbosa on alluvial plains had high densities of small, immature stems < 10 cm dbh (diameter at breast height), and that the density of immature stems decreased with increasing distance from a river. By contrast, there was an absence of small size classes in a population growing on a sandstone escarpment. On limestone substrates, high densities of small size-class stems were observed at a site topographically protected from wildfire, but there was an absence of small size classes at a site exposed to wildfires. Differences in gross allocation patterns, as inferred from relationships between tree height, trunk diameter and height of the swollen trunk, were observed between alluvial, sandstone and limestone substrates. These differences suggest growth rates also differ on distinct substrates. There was a highly significant negative association between the presence of fruit and evidence of recent fire damage for stems greater than 10 cm dbh. This pattern may be related to the destruction of reproductive structures by late dry season fire. However, additional factors appear to control fruit production, as 36% of the unburnt stems > 10 cm dbh also lacked fruit. Juvenile plants resprout from swollen tap roots after wildfire, thus frequent fires would be required to have a long-term impact on stands of A. gibbosa heavily stocked with juveniles that possess swollen tap roots. However, it is unknown at what age juveniles develop swollen tap roots and if all juveniles with swollen tap roots resprout following fire damage. It is hypothesised that the local distribution of A. gibbosa is controlled by fire history, and that changes in fire regimes associated with cattle grazing are causing changes in the distribution of this species. More research is required to critically evaluate this conjecture.


2013 ◽  
Vol 10 (1) ◽  
pp. 101-114 ◽  
Author(s):  
Catherine Martel ◽  
Andrew Taylor ◽  
Dean Carson

Building on Fielding’s idea of escalator regions as places where young people migrate (often temporarily) to get rapid career advancement, this paper proposes a new perspective on 'escalator migration' as it applies to frontier or remote regions in particular. Life events, their timing and iterations have changed in the thirty years since Fielding first coined the term ‘escalator region’, with delayed adulthood, multiple career working lives, population ageing and different dynamics between men and women in the work and family sphere. The object of this paper is to examine recent migration trends to Australia's Northern Territory for evidence of new or emerging 'escalator migrants'.


1991 ◽  
Vol 24 (9) ◽  
pp. 31-43 ◽  
Author(s):  
M. D. Burgess

A harsh climate, extended dry periods and relatively expensive water resources underly the potential for effluent reuse in the Northern Territory, Australia. The cost of supplying potable water and the potential offsetting effects of utilising sewage effluent are reviewed. The need to firmly establish the true cost to the community of different supply options is identified. Major cost benefits accrue where reuse will enable deferment of either significant potable source augmentation or sewage treatment works upgrading and where horticultural prospects are good at a reuse site close to the treatment works. An overall strategy plan for increasing the potential of reuse is described. This plan includes firm cost management procedures, marketing activities, appropriate land planning measures and a commitment to research and development.


2017 ◽  
Vol 6 (2) ◽  
pp. 5256
Author(s):  
Daryoush Shafiei ◽  
Prof. Basavaiah*

In mulberry (Morus spp.), the process of selection of promising hybrids from F1 population requires the screening of a large number of progenies and a long period. To develop a simple and faster approach for screening, studies were conducted using F1 seeds of two crosses. The details of screening studies conducted in relation to seed-size and seedling-size are reported separately in two parts. In this part, the F1 seeds were size-graded as small, medium and large seeds; their progenies were raised separately and screened in nursery. There was a considerable degree of variation in size of seeds and medium-size class seeds were in high percentage in both the crosses. The length, width and weight of seeds were also varied between the seed size classes significantly in both the crosses. The seed size classes differ with high significance in shoot length and Root collar diameter and also differ significantly in root length and weight of seedlings. The positive correlation between the seed size and growth of seedlings, seed size and germination, seed size and seedling survival in nursery indicated that size-grading of seeds and rejection of small seeds in the beginning of screening process may help to increase the efficiency of screening by increasing the chances of getting superior hybrids from limited progenies. However, confirmation on the performance of large seedlings from small seed size class may help to draw conclusion. Hence, the studies are continued with size- grading of seedlings in the next part of screening study.


Author(s):  
Samuel Curkpatrick

The musical project Crossing Roper Bar (CRB) is based on a collaboration between Wägilak songmen from Australia’s Northern Territory and the Australian Art Orchestra (AAO). Individuals drawn into this collaboration bring their distinct voices and histories to performance, while opening themselves to those of others. A new, malleable approach to orchestral performance in Australia is the result of this collaboration, which places improvisation at the centre of conversational musical interaction. This chapter introduces orthodox narrative elements of Wägilak manikay (song) that are creatively renewed and sustained in CRB. It highlights how the collaboration demonstrates the compelling play of musical performance that can generate nuanced, respectful and ongoing interactions between individuals, and between individuals and traditions. Amidst the vibrant, cultural diversity of contemporary Australian society, CRB suggests new possibilities for productive and relevant orchestral music-making.


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