Skip to main content

Forest-fragment quality rather than matrix habitat shapes herbivory on tree recruits in South Africa

  • Alexandra Botzat (a1), Lena Fischer (a1) and Nina Farwig (a1)

Forest fragmentation can alter herbivory on tree recruits with possible consequences for regeneration. We assessed effects of forest-fragment quality (tree diversity, vegetation complexity, relative abundance of pioneer trees) and matrix habitat on arthropods and herbivory in KwaZulu-Natal, South Africa. We compared arthropod abundances and herbivory on woody seedlings and saplings among four forest-fragment types differing in size and matrix (large fragments and small fragments surrounded by natural grassland, eucalypt and sugarcane plantations; nplots = 24) using analyses of covariance. We recorded 3385 arthropods and inspected 897 seedlings (71 species) and 876 saplings (91 species). Relative abundance of predators increased with fragment quality; that of herbivores decreased. Herbivory responses to fragment quality varied: seedling herbivory decreased with relative abundance of pioneers and sapling herbivory increased with vegetation complexity. Matrix effects were low with little variation in relative abundance of predators (0.39–0.53) and herbivores (0.22–0.32), proportion of seedling (8.3–11.0%) and sapling herbivory (12.4–14.3%) among the forest-fragment types. These findings indicate that herbivory on tree recruits is mediated by forest-fragment quality rather than matrix habitat. Future studies should evaluate whether contrasting effects of fragment quality on arthropods and herbivory are caused by weak trophic interactions and variable herbivore compositions.

Corresponding author
1Corresponding author. Email:
Hide All
BALVANERA, P., PFISTERER, A. B., BUCHMANN, N., HE, J. S., NAKASHIZUKA, T., RAFFAELLI, D. & SCHMID, B. 2006. Quantifying the evidence for biodiversity effects on ecosystem functioning and services. Ecology Letters 9:11461156.
BENÍTEZ-MALVIDO, J. & LEMUS-ALBOR, A. 2005. The seedling community of tropical rain forest edges and its interaction with herbivores and pathogens. Biotropica 37:301313.
BIBBY, C. J., BURGESS, N. D., HILL, D. A. & MUSTOE, S. H. 2000. Bird census techniques. Academic Press, London. 302 pp.
BOON, R. 2010. Pooley's trees of eastern South Africa – a complete guide. Flora and Fauna Publications Trust, Durban. 624 pp.
CHAPLIN-KRAMER, R., O'ROURKE, M. E., BLITZER, E. J. & KREMEN, C. 2011. A meta-analysis of crop pest and natural enemy response to landscape complexity. Ecology Letters 14:922932.
COATES PALGRAVE, M. 2005. Keith Coates Palgrave trees of Southern Africa. Struik Publishers, Cape Town. 1000 pp.
COLEY, P. D. 1980. Effects of leaf age and plant life-history patterns on herbivory. Nature 284:545546.
COOPER, K. H. 1985. The conservation status of indigenous forests in the Transvaal, Natal and O.F.S., South Africa. Wildlife Society of Southern Africa, Durban. 108 pp.
CRAWLEY, M. J. 2007. The R book. John Wiley & Sons, Chichester. 951 pp.
DALLING, J. W. & HUBBELL, S. P. 2002. Seed size, growth rate and gap microsite conditions as determinants of recruitment success for pioneer species. Journal of Ecology 90:557568.
EELEY, H. A. C., LAWES, M. J. & PIPER, S. E. 1999. The influence of climate change on the distribution of indigenous forest in KwaZulu-Natal, South Africa. Journal of Biogeography 26:595617.
FAHRIG, L., BAUDRY, J., BROTONS, L., BUREL, F. G., CRIST, T. O., FULLER, R. J., SIRAMI, C., SIRIWARDENA, G. M. & MARTIN, J. L. 2011. Functional landscape heterogeneity and animal biodiversity in agricultural landscapes. Ecology Letters 14:101112.
FAVERI, S. B., VASCONCELOS, H. L. & DIRZO, R. 2008. Effects of Amazonian forest fragmentation on the interaction between plants, insect herbivores, and their natural enemies. Journal of Tropical Ecology 24:5764.
GARCÍA-GUZMÁN, G. & DIRZO, R. 2001. Patterns of leaf-pathogen infection in the understory of a Mexican rain forest: incidence, spatiotemporal variation, and mechanisms of infection. American Journal of Botany 88:634645.
HAYNES, K. J. & CRIST, T. O. 2009. Insect herbivory in an experimental agroecosystem: the relative importance of habitat area, fragmentation, and the matrix. Oikos 118:14771486.
JACTEL, H. & BROCKERHOFF, E. G. 2007. Tree diversity reduces herbivory by forest insects. Ecology Letters 10:835848.
LANGELLOTTO, G. A. & DENNO, R. F. 2004. Responses of invertebrate natural enemies to complex-structured habitats: a meta-analytical synthesis. Oecologia 139:110.
LAURANCE, W. F., DELAMONICA, P., LAURANCE, S. G., VASCONCELOS, H. L. & LOVEJOY, T. E. 2000. Conservation – rainforest fragmentation kills big trees. Nature 404:836.
LAURANCE, W. F., NASCIMENTO, H. E. M., laurance, S. G., ANDRADE, A. C., Fearnside, P. M., Ribeiro, J. E. L. & CAPRETZ, R. L. 2006. Rain forest fragmentation and the proliferation of successional trees. Ecology 87:469482.
LAWES, M. J. 1990. The distribution of the samango monkey (Cercopithecus mitis erythrarchus Peters, 1852 and Cercopithecus mitis labiatus Geoffroy, I., 1843) and forest history in southern Africa. Journal of Biogeography 17:669680.
LAWES, M. J., LAMB, B. C. C. & BOUDREAU, S. 2005. Area- but no edge-effect on woody seedling abundance and species richness in old Afromontane forest fragments. Journal of Vegetation Science 16:363372.
LEIBOLD, M. A., CHASE, J. M., SHURIN, J. B. & DOWNING, A. L. 1997. Species turnover and the regulation of trophic structure. Annual Review of Ecology and Systematics 28:467494.
MARON, J. L. & CRONE, E. 2006. Herbivory: effects on plant abundance, distribution and population growth. Proceedings of the Royal Society B–Biological Sciences 273:25752584.
MCCANN, K., HASTINGS, A. & HUXEL, G. R. 1998. Weak trophic interactions and the balance of nature. Nature 395:794798.
PICKER, M., GRIFFITHS, C. & WEAVING, A. 2004. Field guide to insects of South Africa. Struik Publishers, Cape Town. 440 pp.
POLIS, G. A., SEARS, A. L. W., HUXEL, G. R., STRONG, D. R. & MARON, J. 2000. When is a trophic cascade a trophic cascade? Trends in Ecology and Evolution 15:473475.
RICHARDS, L. A. & COLEY, P. D. 2007. Seasonal and habitat differences affect the impact of food and predation on herbivores: a comparison between gaps and understory of a tropical forest. Oikos 116:3140.
ROOT, R. B. 1973. Organization of a plant–arthropod association in simple and diverse habitats – fauna of collards (Brassica oleracea). Ecological Monographs 43:95120.
RUIZ-GUERRA, B., GUEVARA, R., MARIANO, N. A. & DIRZO, R. 2010. Insect herbivory declines with forest fragmentation and covaries with plant regeneration mode: evidence from a Mexican tropical rain forest. Oikos 119:317325.
SALA, O. E., CHAPIN, F. S., ARMESTO, J. J., BERLOW, E., BLOOMFIELD, J., DIRZO, R., HUBER-SANWALD, E., HUENNEKE, L. F., JACKSON, R. B., KINZIG, A., LEEMANS, R., LODGE, D. M., MOONEY, H. A., OESTERHELD, M., POFF, N. L., SYKES, M. T., WALKER, B. H., WALKER, M. & WALL, D. H. 2000. Biodiversity – global biodiversity scenarios for the year 2100. Science 287:17701774.
SCHOLTZ, C. H. & HOLM, E. 1985. Insects of Southern Africa. Butterworths, Durban. 502 pp.
SCHULDT, A., BARUFFOL, M., BOHNKE, M., BRUELHEIDE, H., HARDTLE, W., LANG, A. C., NADROWSKI, K., VON OHEIMB, G., VOIGT, W., ZHOU, H. Z. & ASSMANN, T. 2010. Tree diversity promotes insect herbivory in subtropical forests of south-east China. Journal of Ecology 98:917926.
SOBEK, S., SCHERBER, C., STEFFAN-DEWENTER, I. & TSCHARNTKE, T. 2009. Sapling herbivory, invertebrate herbivores and predators across a natural tree diversity gradient in Germany's largest connected deciduous forest. Oecologia 160:279288.
STEFFAN-DEWENTER, I. 2003. Importance of habitat area and landscape context for species richness of bees and wasps in fragmented orchard meadows. Conservation Biology 17:10361044.
TERBORGH, J., LOPEZ, L., NUÑEZ, P., RAO, M., SHAHABUDDIN, G., ORIHUELA, G., RIVEROS, M., ASCANIO, R., ADLER, G. H., LAMBERT, T. D. & BALBAS, L. 2001. Ecological meltdown in predator-free forest fragments. Science 294:19231926.
TSCHARNTKE, T. & BRANDL, R. 2004. Plant–insect interactions in fragmented landscapes. Annual Review of Entomology 49:405430.
TSCHARNTKE, T., KLEIN, A. M., KRÜSS, A., STEFFAN-DEWENTER, I. & THIES, C. 2005. Landscape perspectives on agricultural intensification and biodiversity – ecosystem service management. Ecology Letters 8:857874.
TSCHARNTKE, T., BOMMARCO, R., CLOUGH, Y., CRIST, T. O., KLEIJN, D., RAND, T. A., TYLIANAKIS, J. M., VAN NOUHUYS, S. & VIDAL, S. 2007. Conservation biological control and enemy diversity on a landscape scale. Biological Control 43:294309.
TYLIANAKIS, J. M., DIDHAM, R. K., BASCOMPTE, J. & WARDLE, D. A. 2008. Global change and species interactions in terrestrial ecosystems. Ecology Letters 11:13511363.
VALLADARES, G., SALVO, A. & CAGNOLO, L. 2006. Habitat fragmentation effects on trophic processes of insect–plant food webs. Conservation Biology 20:212217.
WHITE, J. A. & WHITHAM, T. G. 2000. Associational susceptibility of cottonwood to a box elder herbivore. Ecology 81:17951803.
WIRTH, R., MEYER, S. T., LEAL, I. R. & TABARELLI, M. 2008. Plant herbivore interactions at the forest edge. Progress in Botany 69:423448.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Journal of Tropical Ecology
  • ISSN: 0266-4674
  • EISSN: 1469-7831
  • URL: /core/journals/journal-of-tropical-ecology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 1
Total number of PDF views: 31 *
Loading metrics...

Abstract views

Total abstract views: 391 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 24th April 2018. This data will be updated every 24 hours.