Skip to main content Accessibility help
×
Home

Coping with herbivory at the juvenile stage: responses to defoliation and stem browsing in the African savanna tree Colophospermum mopane

  • David C. Hartnett (a1), Jacqueline P. Ott (a1), Kathryn Sebes (a1) and Marks K. Ditlhogo (a2)

Abstract:

Responses of plants to herbivory are dependent on the type of damage and the ontogenetic stage of the plant. We compared the effects of stem pruning and defoliation on seedlings of Colophospermum mopane, an ecologically important tree species widely distributed in southern Africa. The growth of 160 greenhouse-grown juveniles were measured for 6-mo after germination and then 6-mo after treatments including 50% defoliation, 100% defoliation, 50% stem pruning and controls. Pruning resulted in 30% reductions in total leaf area, height and biomass. Partial defoliation resulted in 30% reductions in total leaf area and plant biomass. However, complete defoliation resulted in a 30% increase in biomass production, a doubling in leaf and lateral branch number, a 45% reduction in leaf size, and no change in total leaf area. Thus, completely defoliated seedlings showed greater performance than those that were only partially defoliated, indicating that C. mopane has become adapted to the chronic and severe defoliation inflicted by Imbrasia belina caterpillars. Comparison of our results with other studies indicates that C. mopane seedlings are less herbivory-tolerant than adults and that pruning has more negative effects than defoliation. Thus, seedling browsers may constrain recruitment in C. mopane, influencing its population dynamics and abundance.

Copyright

Corresponding author

1Corresponding author. Email: dchart@ksu.edu

References

Hide All
BELSKY, A. J. 1984. Role of small browsing mammals in preventing woodland regeneration in Serengeti National Park, Tanzania. African Journal of Ecology 22:271279.
BERGSTROM, R., SKARPE, C. & DANELL, K. 2000. Plant responses and herbivory following simulated browsing and stem cutting of Combretum apiculatum. Journal of Vegetation Science 11:409414.
BOEGE, K. & MARQUIS, R. 2005. Facing herbivory as you grow up: the ontogeny of resistance in plants. Trends in Ecology and Evolution 20:441448.
BRYANT, J. P., HEITKÖNIG, I., KUROPAT, P. & OWEN-SMITH, N. 1991. Effects of severe defoliation on the long-term resistance to insect attach and on leaf chemistry in six woody species of the Southern African savanna. American Naturalist 137:5063.
COATES PALGRAVE, K. 2000. Trees of southern Africa. (Second edition). Struik Publishers, Cape Town. 959 pp.
DIRZO, R. 1984. Herbivory: a phytocentric overview. Pp. 141165 in Dirzo, R. & Sarukhan, J. (eds). Perspectives on plant population ecology. Sinauer Associates, Sunderland. 478 pp.
DITLHOGO, M. K. 1996. The natural history of Imbrasia belina (Westwood) (Lepidoptera: Saturniidae) and some factors affecting its abundance in north-eastern Botswana. Ph.D. thesis, University of Manitoba, Winnipeg, Canada.
DUBLIN, H. T., SINCLAIR, A. R. E. & MCGLADE, J. 1990. Elephants and fire as causes of stable states in Serengeti Mara woodlands. Journal of Animal Ecology 59:11471164.
GADD, M. E., YOUNG, T. P. & PALMER, T. M. 2001. Effects of simulated shoot and leaf herbivory on vegetative growth and plant defence in Acacia drepanolobium. Oikos 92:515521.
HIGGINS, S. I., BOND, W. J. & TROLLOPE, W. S. W. 2000. Fire, resprouting and variability: a recipe for grass–tree coexistence in savanna. Journal of Ecology 88:213229.
HRABAR, H., HATTAS, D. & DU TOIT, J. T. 2009. Differential effects of defoliation by mopane caterpillars and pruning by African elephants on the re-growth of Colophospermum mopane foliage. Journal of Tropical Ecology 25:301309.
LEHTILA, K., HAUKIOJA, E., KAITANIEMI, P. & LAINE, K. A. 2000. Allocation of resources within mountain birch canopy after simulated winter browsing. Oikos 90:160170.
MESSINA, F. J., DURHAM, S. L., RICHARDS, J. H. & MCARTHUR, E. D. 2002. Trade-off between plant growth and defence? A comparison of sagebrush populations. Oecologia 131:4351.
MOE, S. R., RUTINA, L. P., HYTTEBORN, H. & DU TOIT, J. T. 2009. What controls woodland regeneration after elephants have killed the big trees? Journal of Applied Ecology 46:223230.
MORUAKGOMO, M. B. W. 1996. Commercial utilization of Botswana's veld products – the economics of Phane: the dimension of Phane trade. Pp. 2331 in Gashe, A. B. & Mpuchane, S. F. (eds). Phane – Proceedings of the first multidisciplinary symposium on Phane. Department of Biological Sciences & Kalahari Conservation Society, Gaborone.
OBERPRIELER, R. G. 1995. The emperor moths of Namibia. Sigma Press, Pretoria. 91 pp.
PALMER, E. & PITMAN, N. 1973. Trees of southern Africa covering all known indigenous species in the Republic of South Africa, South-West Africa, Botswana, Lesotho and Swaziland. Balkema, Cape Town. 736 pp.
PIENE, H., MACLEAN, D. A. & LANDRY, M. 2003. Spruce budworm defoliation and growth loss in young balsam fir: relationships between volume growth and foliage weight in spaced and un-spaced, defoliated and protected stands. Forest Ecology and Management 179:3753.
PINHEY, E. C. G. 1972. Emperor moths of South and Central Africa. Struik Publishers, Cape Town. 150 pp.
ROOKE, T. & BERGSTROM, R. 2007. Growth, chemical responses and herbivory after simulated leaf browsing in Combretum apiculatum. Plant Ecology 189:201212.
ROOKE, T., BERGSROM, R., SKARPE, C. & DANELL, K. 2004. Morphological responses of woody species to simulated twig-browsing in Botswana. Journal of Tropical Ecology 20:281289.
RUESS, R. W. & HALTER, F. C. 1990. Impact of large herbivores on the Seronela woodlands, Serengeti National Park, Tanzania. African Journal of Ecology 28:259275.
SANKARAN, M., RATNAM, J. & HANAN, N. P. 2004. Tree coexistence in savannas revisited – insights from an examination of assumptions and mechanisms invoked in existing models. Ecology Letters 7:480490.
SMALLIE, J. J. & O'CONNOR, T. G. 2000. Elephant utilization of Colophospermum mopane: possible benefits of hedging. African Journal of Ecology 38:352359.
STAVER, A. C., BOND, W. J., STOCK, W. D., VAN RENSBURG, S. J. & WALDRAM, M. S. 2009. Browsing and fire interact to suppress tree density in an African savanna. Ecological Applications 19:19091919.
TAYLOR, F. W. 1982. Final report on the potential for commercialization of veld products. Volume II: The resources and its commercial exploitation. Government Printer, Gaborone, Botswana. 255 pp.
VENTER, F. & VENTER, J. 2007. Indigenous trees. Briza Publications, Pretoria. 320 pp.

Keywords

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed