Defoliation regrowth and dry matter partitioning in the two arid zone grasses, Aristida armata and Thyridolepis mitchelliana
- 1 January 1987
- journal article
- research article
- Published by CSIRO Publishing in Australian Journal of Agricultural Research
- Vol. 38 (5), 881-893
- https://doi.org/10.1071/ar9870881
Abstract
Plants of the desirable rangeland grass, Thyridolepis mitchelliana, and its undesirable companion, Aristida armata, were defoliated at various ages, and their subsequent regrowth and seed production compared with that of intact plants. Young plants of T. mitchelliana, but not A. armata, often failed to survive severe defoliation. Seed production by A. armata greatly exceeded that of T. mitchelliana and was much less affected by defoliation. In both defoliated and intact plants, the proportion of dry matter in inflorescences was several times greater for A. armata than T. mitchelliana, but the reverse occurred with leaf production. Root growth was little affected by defoliation, and there was no evidence of export of root material to support tops regrowth. Total plant production of both species was unaffected by the loss of half the tops, but was depressed by more severe defoliation. The differences between the two species in their reaction to defoliation seem sufficient to explain the displacement of T. mitchelliana by A. armata which followed the introduction of domestic livestock. Under grazing, A. armata is likely to have a reproductive advantage, and the implications of this for pasture management are examined.Keywords
This publication has 2 references indexed in Scilit:
- Fertilizer Effects on above- and Belowground Biomass of Four SpeciesJournal of Range Management, 1982
- Effects of Rest following Defoliations on the Recovery of Several Range SpeciesJournal of Range Management, 1977