Sustainable harvest rates of ironwood, Erythrophleum chlorostachys, in the Northern Territory, Australia
Garry D. Cook A D , Robert J. Taylor B , Richard J. Williams A and the late John C. G. Banks CA Tropical Savannas Management CRC and CSIRO Sustainable Ecosystems, PMB 44, Winnellie, Darwin, NT 0822, Australia.
B Biodiversity Conservation, Department of Infrastructure Planning and Environment, PO Box 496, Palmerston, NT 0831, Australia. Present Address: Environmental Services Corporate Services and Infrastructure Northern Territory/Kimberley Department of Defence, Defence Establishment Berrimah PMB 13, Winnellie, NT 082, Australia.
C School of Resources, Environment and Society, Australian National University, Canberra, ACT 0200, Australia.
D Corresponding author. Email: Garry.Cook@csiro.au
Australian Journal of Botany 53(8) 821-826 https://doi.org/10.1071/BT05003
Submitted: 4 January 2005 Accepted: 11 July 2005 Published: 14 December 2005
Abstract
Ironwood, Erythrophleum chlorostachys (F.Muell.) Baill., is harvested for timber in the Northern Territory. Available data on ironwood growth rates and stand structures were collated to help inform sustainable management. In 32 plots (0.1 ha each) within 300 km2 of a widespread savanna vegetation type in the Northern Territory, ironwood trees represent ∼11% of the total basal area of all trees and 12% of all individual trees >3 m high. Nevertheless, the density of potentially harvestable trees with a diameter at breast height >35 cm is low at 150 km–2, whereas the density of trees in the preferred size of >40 cm is only 30 km–2. The slow growth rate means that the sustainable harvest is only 1.8 trees km–2 year–1. This represents a maximum estimate that does not account for the high rate of poorly formed boles and the lower density of ironwood throughout most of its range. Limited data on tree growth rates of isolated seedlings and coppice indicate that trees could reach harvestable sizes in decades instead of centuries if competition with other species is reduced; however, there has been no assessment of the relative wood quality of fast- and slow-growing ironwoods.
Acknowledgments
Funding was provided by Agriculture, Fisheries and Forestry Australia through their Montreal Criteria and Indicators program. Mike Clark of Greening Australia provided information on planting dates and location of the trees at Berrimah. Richard Luxton provided the historic photographs in Fig. 2. We thank Jack Cusack, the late Judy McCutcheon and Ivan McManus for measuring trees at Kapalga, and the managers and traditional owners of Kakadu National Park for access to the sites. Robert Eager, Alan Andersen and Alaric Fisher provided helpful comments on the draft manuscript.
Andersen AN,
Braithwaite RW,
Cook GD,
Corbett LK,
Williams RJ,
Douglas MM,
Gill AM,
Setterfield SA, Muller WJ
(1998) Fire research for conservation management in tropical savannas: introducing the Kapalga fire experiment. Australian Journal of Ecology 23, 95–110.
Boland, DJ ,
Brooker, MIH ,
Chippendale, GM ,
Hall, N ,
Hyland, BPM ,
Johnstone, RD ,
Kleinig, DA ,
and
Turner, JD (1984).
Brock, J (1988).
Buhmann J,
Robins R, Cause M
(1976) Wood identification of spearthrowers in the Queensland Museum. Newsletter. Australian Institute of Aboriginal Studies 5, 43–44.
Chidumayo E, Frost P
(1996) Population biology of miombo trees. In ‘The Miombo in transition: woodlands and welfare in Africa’. (Ed. B Campbell)
pp. 59–71. (Center for International Forestry Research: Bogor, Indonesia)
Cook GD, Corbett LK
(2003) Kapalga and the fire experiment. In ‘Fire in tropical savannas: the Kapalga fire experiment’. (Eds AN Andersen, GD Cook, RJ Williams)
pp. 15–32. (Springer-Verlag: New York)
Cook GD,
Liedloff AC,
Eager RW,
Chen X,
Williams RJ,
O’Grady AP, Hutley LB
(2005) The estimation of carbon budgets of frequently burnt tree stands in savannas of northern Australia using allometric analysis and isotopic discrimination. Australian Journal of Botany 53, 621–630.
| Crossref |
Durrieu de Madron L, Forni E
(1997) Forest management in eastern Cameroon: stand structure and logging periodicity. Bois et Forets des Tropiques 254, 39–50.
Fensham RJ, Bowman DMJS
(1992) Stand structure and the influence of overwood on regeneration in tropical eucalypt forest on Melville Island. Australian Journal of Botany 40, 335–352.
Fox RE, Clark NB
(1972) The incidence of termites in eucalypts of the Darwin area. Australian Forest Research 5, 29–36.
Gerard J
(1991) Gutta percha, ironwood and lancewood. Three new valuable species from north Australia. An example of technological selection and promotion of lesser known tropical species. Bois et Forets des Tropiques 228, 63–73.
Gotz, E (1983).
Granger L, Taylor R
(2002) Regeneration in logged and unlogged sites. In ‘Ironwood in the Northern Territory: aspects of its ecology in relation to timber harvesting’. (Ed. R Taylor)
pp. 101–112. (Northern Territory Department of Infrastructure, Planning and Environment: Palmerston, NT)
Guinto DF,
House APN,
Xu ZH, Saffingna PG
(1999) Impacts of repeated fuel reduction burning on tree growth, mortality and recruitment in mixed species eucalypt forests of southeast Queensland, Australia. Forest Ecology and Management 115, 13–27.
| Crossref | GoogleScholarGoogle Scholar |
Hanssen NL, Wigston DL
(1989) Approaches to a forest history of the Northern Territory. In ‘Australia’s ever-changing forests’. (Eds KJ Frawley, N Semple)
(Department of Geography and Oceanography, University College, Australian Defence Force Academy: Campbell, ACT)
Iwainde F
(1998) Regeneration of Cooktown ironwood in Mary River East Station in the Northern Territory of Australia. Masters Thesis in Tropical Environmental Management
(Northern Territory University:
Darwin)
Koumba Zaou P,
Mapaga D,
Nze Nguema S, Deleporte P
(1998) Growth of thirteen timber species pleated in Gabonese forest. Bois et Forets des Tropiques 256, 21–33.
Mucha SB
(1979) Estimation of tree ages from growth rings of eucalypts in northern Australia. Australian Forestry 42, 13–16.
Prior LD,
Eamus D, Bowman DMJS
(2004) Tree growth rates in north Australian savanna habitats: seasonal patterns and correlations with leaf attributes. Australian Journal of Botany 52, 303–314.
| Crossref | GoogleScholarGoogle Scholar |
Taylor R, Granger L, Perry L
(2002) Timber harvesting in the Northern Territory. In ‘Ironwood in the Northern Territory: aspects of its ecology in relation to timber harvesting’. (Ed. R Taylor)
pp. 113–120. (Northern Territory Department of Infrastructure, Planning and Environment: Palmerston, NT)
Werner PA
(1986) Population dynamics and productivity of selected forest trees in Kakadu National Park. Final Report to Australian National Parks and Wildlife Service. CSIRO Tropical Ecosystems Research Centre, Darwin.
Williams RJ,
Cook GD,
Gill AM, Moore PHR
(1999a) Fire regime, fire intensity and tree survival in a tropical savanna in northern Australia. Australian Journal of Ecology 24, 50–59.
| Crossref | GoogleScholarGoogle Scholar |
Williams RJ,
Myers BA,
Eamus D, Duff GA
(1999b) Reproductive phenology of woody species in a north Australia tropical savanna. Biotropica 31, 626–636.
Wilson BA, Brocklehurst PS, Clark MJ, Dickinson KJM
(1990)
Woinarski JCZ, Dawson F
(2001) Limitless lands and limited knowledge: coping with uncertainty and ignorance in northern Australia. In ‘Ecology, uncertainty and policy: managing ecosystems for sustainability’. (Eds TW Norton, JW Handmer, SR Dovers)
pp. 83–115. (Pearson Education: New York)
Woinarski J, Beggs K, Hempel C, Price O, Fisher A
(2002) Ironwood: an ecological summary. In ‘Ironwood in the Northern Territory: aspects of its ecology in relation to timber harvesting’. (Ed. R Taylor)
pp. 10–21. (Northern Territory Department of Infrastructure, Planning and Environment: Palmerston, NT)
Woinarski J, Beggs K, Hempel C, Price O, Fisher A
(2002) Distribution and biomass in the Northern Territory. In ‘Ironwood in the Northern Territory: aspects of its ecology in relation to timber harvesting’. (Ed. R Taylor)
pp. 22–68. (Northern Territory Department of Infrastructure, Planning and Environment: Palmerston, NT)
