Pasture production in cleared and uncleared grazing systems of central Queensland, Australia
K. Kaur A D , R. K. Jalota B , D. J. Midmore A and J. Rolfe CA Plant Sciences Group, Primary Industries Research Centre, Central Queensland University, Rockhampton, Qld 4702, Australia.
B Centre for Environment Management, Central Queensland University, Emerald Campus, Qld 4720, Australia.
C Central Queensland University, Emerald Campus, Emerald, Qld 4720, Australia.
D Corresponding author. Email: Kamaljit.sangha@jcu.edu.au
The Rangeland Journal 27(2) 143-149 https://doi.org/10.1071/RJ05012
Submitted: 31 December 2004 Accepted: 2 September 2005 Published: 21 November 2005
Abstract
Clearing land of trees and introducing exotic pastures to enhance pasture and cattle production and hence enterprise financial performance are widely practised in Queensland. The results from many previous studies on tree clearing have emphasised the gains in pasture production, but over periods of less than 10–15 years after clearing. The present study questioned the sustainability of pasture production in cleared systems over a longer time-frame (>10 years of clearing). For this, three different age groups of clearing i.e. 5 year, 11–13 year and 33 year were selected in each of 3 major types of tree communities i.e. Eucalyptus populnea, E. melanophloia and Acacia harpophylla in central Queensland. Paired comparisons of cleared and uncleared (intact) pasture systems were selected for each age group of clearing. The results suggest that the initial gains in pasture production upon clearing were compatible with published studies. However, for longer periods of time since clearing, the gains in pasture production were not sustained and were accompanied by risks of land degradation and loss of pasture plant diversity. For E. populnea and A. harpophylla, the maximum benefits from clearing were achieved at 13–15 years whereas for E. melanophloia, any benefits existed only over a short period of 5–6 years. The study emphasises that each tree community exhibits a specific response with regard to the duration of increased pasture production following clearing. To estimate the total benefits from tree clearing in pasture development, it is important to consider both monetary benefits and non-monetary losses from clearing for different types of tree communities.
Additional keywords: woodland pastures, soils, time after clearing.
Acknowledgments
Our sincere thanks to the landholders Mrs. and Mr. Spooner for permission to carry out this research on their property and for their co-operation during the field work. The laboratory space and equipment provided by the Department of Natural Resources and Mines and the Department of Primary Industries at Emerald is highly acknowledged. Funds were provided by Central Queensland University, Queensland. Thanks to anonymous reviewers for their comments to improve this manuscript.
ABS (2003).
Back P. V.,
Anderson E. R.,
Burrows W. H.,
Kennedy M. J. J., Carter J. O.
(1997)
Burrows W. H.
(1993) Deforestation in savanna context – problems and benefits for pastoralism. : ‘Grasslands for our world. XVII International Grassland Congress’. (Ed. M. J. Baker )
pp. 839–846. (SIR Publishing: New Zealand and Queensland.)
Burrows W. H.
(2002) Harry Stobbs Memorial Lecture, 2002. Seeing the wood(land) for the trees - an individual perspective of Queensland woodland studies (1965–2005). Tropical Grasslands 36, 202–217.
Burrows B., Scanlan J. C., Anderson E. R.
(1988) Plant ecological relations in open forests, woodlands and shrublands. : ‘Native pastures in Queensland’. (Eds W. H. Burrows, J. C. Scanlan, M. T. Rutherford)
pp. 72–90. (Queensland Department of Primary Industries, Queensland Government: Brisbane.)
Burrows W. H.,
Carter J. O.,
Scanlan J. C.,, Anderson E. R.
(1990) Management of savannas for livestock production in north-east Australia: contrasts across the tree-grass continuum. Journal of Biogeography 17, 503–512.
Converys M. K.
(1999) Factors affecting soil test interpretation. : ‘Soil analysis – an interpretation manual’. (Eds K. I. Peverill, L. A. Sparrow, D. J. Reuter)
pp. 23–24. (CSIRO Publishing: Melbourne.)
Department of Natural Resources and Mines (2003).
GenStat Committee (2002).
Henderson, P. A. ,
and
Seaby, R. M. H. (1998).
Jackson J., Ash A. J.
(1998) Tree-grass relationships in open eucalypt woodlands of northeastern Australia: influence of trees on pasture productivity, forage quality and species distribution. Agroforestry Systems 40, 159–176.
| Crossref | GoogleScholarGoogle Scholar |
Jackson J., Ash A. J.
(2001) The role of trees in enhancing soil nutrient availability for native perennial grasses in open eucalypt woodlands of north-east Queensland. Australian Journal of Agricultural Research 52, 377–386.
| Crossref | GoogleScholarGoogle Scholar |
Kent, M. ,
and
Coker, P. (1992).
Lawrence P. A., Cowie B. A., Graham T. W. G., Catchpoole V.
(1988) Fertility decline.
: ‘Sown pastures for the brigalow lands’. Conference and workshop series, C94005. (Ed. I. J. Partridge ,
B. Burrows ,
E. J. Weston )
pp. 23–25. (Department of Primary Industries: Brisbane.)
Mordelet P., Menaut J. C.
(1995) Influence of trees on above ground production dynamics of grasses in a humid savanna. Journal of Vegetation Science 6, 223–228.
Obot E. A.
(1988) Estimating the optimum tree density for maximum herbaceous production in Guinea savanna of Nigeria. Journal of Arid Environments 14, 267–273.
Patterson H. D., Thompson R.
(1971) Recovery of inter-block information when block sizes are unequal. Biometrika 58, 545–554.
Rolfe J.
(2002) Economics of vegetation clearing in Queensland. The Rangeland Journal 24, 152–169.
Sangha K.,
Jalota R., Midmore D. J.
(2005) Impact of tree clearing on soil pH and nutrient availability in grazing systems of central Queensland, Australia. Australian Journal of Soil Research 43, 51–60.
| Crossref | GoogleScholarGoogle Scholar |
Scanlan J. C.
(1991) Woody overstorey and herbaceous understorey biomass in Acacia harpophylla (Brigalow) woodlands. Australian Journal of Ecology 16, 521–529.
Scanlan J. C.
(2002) Some aspects of tree-grass dynamics in Queensland’s grazing lands. The Rangeland Journal 24, 56–81.
Scanlan J. C.,, Burrows W. H.
(1990) Woody overstorey impact on herbaceous understorey in Eucalyptus spp. communities in Central Queensland. Australian Journal of Ecology 15, 191–197.
Tilman D.,
Knops J.,
Wedin D.,
Reich P.,
Ritchie M.,, Siemann E.
(1997) The influence of functional diversity and composition on ecosystem processes. Science 277, 1300–1302.
| Crossref | GoogleScholarGoogle Scholar |
Vance E. D.,
Brookes P. C., Jenkinson D. S.
(1987) An extraction method for measuring soil microbial biomass C. Soil Biology and Biochemistry 19, 703–707.
| Crossref | GoogleScholarGoogle Scholar |
Walker J.,
Moore R. M., Robertson J. A.
(1972) Herbage response to tree and shrub thinning in Eucalyptus populnea shrub woodlands. Australian Journal of Agricultural Research 23, 405–410.
| Crossref | GoogleScholarGoogle Scholar |
Walker J.,
Robertson J. A.,
Penridge L. K., Sharpe P. J. H.
(1986) Herbage response to tree thinning in a Eucalyptus crebra woodland. Australian Journal of Ecology 11, 135–141.
Weltzin J. F., Coughenour M. B.
(1990) Savanna tree influence on understorey vegetation and soil nutrients in northwestern Kenya. Journal of Vegetation Science 1, 325–332.
Wilson S. D.
(1998) Competition between grasses and woody plants. : ‘Population biology of grasses’. (Ed. G. P. Cheplick )
pp. 231–254. (Cambridge University Press: Cambridge, UK.)
