Biodiversity & Conservation

, Volume 13, Issue 2, pp 437–452 | Cite as

Composition and diversity of the spider fauna in the canopy of a montane forest in Tanzania

  • Line L. Sørensen


Spiders were sampled using insecticide knockdown in an African montane forest in the Uzungwa Mountains of Tanzania. The results are used to discuss the faunal composition at the site and in comparison to other sites, and the implications of the results for estimating spider diversity in Africa are discussed. A total of 5233 adults comprising 149 species were collected from 11 samples covering a total of 906 m2 of projected area. Three species contributed 45% of the sample. Previous insecticide knockdown studies of tropical lowland forest canopies have shown a dominance of Theridiidae, Salticidae and Araneidae. In the present study Linyphiidae dominated in abundance and were the second most diverse in terms of species richness. Other abundant families were Oonopidae and Pholcidae, while Theridiidae, Salticidae and Araneidae were rich in species. This supports a previous study, which indicated that the importance of linyphiids increases with altitude. Species richness was predicted using a number of estimators, which produced relatively similar results. Using the abundance-based estimator, Chao 1, the predicted richness for the total area sampled is 183 ± 15 species. This indicates that at least 20% of the area's spider community remains unsampled. A high ratio of undescribed species (approximately 80%) and a relatively high species turnover compared to a site 20 km away within the same forest complex suggests that the number of spiders in Africa could well be much higher than the current, published estimate of 20000 species.

Insecticide knockdown sampling Species richness 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Adis J. and Harvey M.S. 2000. How many Arachnida and Myriapoda are there world-wide and in Amazonia. Studies on Neotropical Fauna and Environment 35: 139–141.Google Scholar
  2. Adis J., Harada A.Y., da Fonseca C.R.V., Paarmann W. and Rafael J.A. 1998. Arthropods obtained from the Amazonian tree species 'Cupiuba' (Goupia glabra) by repeated canopy fogging with natural pyrethrum. Acta Amazonica 28: 273–283.Google Scholar
  3. Adis J., Lubin Y.D. and Montgomery G.G. 1984. Arthropods from the canopy of inundated and terra firme forests near Manaus, Brazil, with critical considerations on the pyrethrum-fogging technique. Studies on Neotropical Fauna and Environment 19: 223–236.Google Scholar
  4. Adis J., Paarmann W., da Fonseca C.R.V. and Rafael J.A. 1997. Knock-down efficiency of natural pyrethrum and survival rate of living arthropods obtained by canopy fogging in Central Amazonia. In: Stork N.E., Adis J. and Didham R.K. (eds), Canopy Arthropods. Chapman & Hall, London, pp. 67–81.Google Scholar
  5. Alderweireldt M. and Jocque R. 1994. Biodiversity in Africa and Europe: the case of spiders (Araneae). Biologisch Jaarboek Dodonaea 61: 57–67.Google Scholar
  6. Basset Y. 1990. The arboreal fauna of the rainforest tree Argyrodendron actinophyllum as sampled with restricted canopy fogging: composition of the fauna. The Entomologist 109: 173–183.Google Scholar
  7. Basset Y. 1991. The taxonomic composition of the arthropod fauna associated with an Australian rainforest tree. Australian Journal of Zoology 39: 171–190.Google Scholar
  8. Basset Y. 2001. Invertebrates in the canopy of tropical rain forests: how much do we really know? Plant Ecology 153: 87–107.Google Scholar
  9. Basset Y. and Arthington A.H. 1992. The arthropod community of an Australian rainforest tree: abundance of component taxa, species richness and guild structure. Australian Journal of Ecology 17: 89–98.Google Scholar
  10. Basset Y., Springate N.D., Aberlenc H.P. and Delvare G. 1997. A review of methods for sampling arthropods in tree canopies. In: Stork N.E., Adis J. and Didham R.K. (eds), Canopy Arthropods. Chapman & Hall, London, pp. 27–52.Google Scholar
  11. Chao A. 1984. Non-parametric estimation of the number of classes in a population. Scandinavian Journal of Statistics 11: 265–270.Google Scholar
  12. Chazdon R.L., Colwell R.K., Denslow J.S. and Guariguata M.R. 1998. Statistical methods for estimating species richness of woody regeneration in primary and secondary rain forests of northeastern Costa Rica. In: Dallmeier F. and Comisky J.A. (eds), Forest Biodiversity Research, Monitoring and Modelling: Conceptual Background and Old World Case Studies. Man and the Biosphere Vol. 20. Parthenon Press, Paris, France, pp. 285–309.Google Scholar
  13. Coleman B.D. 1981. On random placement and species-area relations. Mathematical Bioscience 54: 191–215.Google Scholar
  14. Coleman B.D., Mares M.A., Willig M.R. and Hsieh Y.-H. 1982. Randomness, area, and species richness. Ecology 63: 1121–1133.Google Scholar
  15. Colwell R.K. 1997. EstimateS: Statistical Estimation of Species Richness and Shared Species from Samples. Version 5. User's Guide and Application. Published at: http: / / /estimates.Google Scholar
  16. Colwell R.K. and Coddington J.A. 1994. Estimating the extent of terrestrial biodiversity through extrapolation. Philosophical Transactions of the Royal Society of London B 345: 101–118.Google Scholar
  17. Dippenaar-Schoeman A.S. and Jocqué R. 1997. African Spiders: An Identification Manual.: Plant Protection Research Institute Handbook 9. Biosystematics Division, Pretoria, South Africa.Google Scholar
  18. Emerit M. 1997. A contribution to the knowledge of Malagasy spiders: the presence of Chorizopinae, an Asian subfamily of Araneidae. Revue Arachnologique 12: 43–52.Google Scholar
  19. Erwin T.L. 1989. Canopy arthropod biodiversity: a chronology of sampling techniques and results. Revista Peruana Entomologia 32: 71–77.Google Scholar
  20. Gagné W.C. 1979. Canopy-associated arthropods in Acacia koa and Metrosideros tree communities along an altitudinal transect in Hawaii Island. Pacific Insects 21: 56–82.Google Scholar
  21. Gotelli N.J. and Colwell R.K. 2001. Quantifying biodiversity: procedures and pitfalls in the measurement and comparison of species richness. Ecology Letters 4: 379–391.Google Scholar
  22. Greenstone M.W. 1984. Determinants of web spider species diversity: vegetational structural diversity vs. prey availability. Oecologia 62: 299–304.Google Scholar
  23. Guilbert E. 1997. Arthropod biodiversity in the canopy of New Caledonian forests. In: Stork N.E., Adis J. and Didham R.K. (eds), Canopy Arthropods. Chapman & Hall, London, pp. 265–277.Google Scholar
  24. Guilbert E., Baylac M. and Najt J. 1995. Canopy arthropod diversity in a new Caledonian primary forest sampled by fogging. Pan-Pacific Entomologist 71: 3–12.Google Scholar
  25. Guilbert E., Chazeau J. and Larbogne L.D. 1994. Canopy arthropod diversity of New Caledonian forests sampled by fogging: preliminary results. Memoirs of the Queensland Museum 36: 77–85.Google Scholar
  26. Halaj J., Ross D.W. and Moldenke A.R. 1998. Habitat structure and prey availability as predictors of the abundance and community organization of spiders in Western Oregon forest canopies. Journal of Arachnology 26: 203–220.Google Scholar
  27. Halaj J., Ross D.W. and Moldenke A.R. 2000. Importance of habitat structure to the arthropod food-web in Douglas-fir canopies. Oikos 90: 139–152.Google Scholar
  28. Höfer H., Brescovit A.D., Adis J. and Paarman W. 1994. The spider fauna of neotropical tree canopies in Central Amazonia: first results. Studies on Neotropical Fauna and Environment 29: 23–32.Google Scholar
  29. Jennings D.T. and Collins J.A. 1987. Coniferous-habitat associations of spiders (Araneae) of red spruce foliage. Journal of Arachnology 14: 315–325.Google Scholar
  30. Jocqué R. 1984. Considérations concernant l'abondance relative des araignées errantes et des araignées à toile vivant au niveau du sol. Revue Arachnologique 5: 193–204.Google Scholar
  31. Kitching R.L., Bergelson J.M., Lowman M.D., McIntyre S. and Carruthers G. 1993. The biodiversity of arthropods from Australian canopies: general introduction, methods, sites and ordinal results. Australian Journal of Ecology 18: 181–191.Google Scholar
  32. Krebs C.J. 1989. Ecological Methodology. Harper Collins Publishers, New York.Google Scholar
  33. Liao C.-H., Li Y.-Q. and Lin S.-M. 1993. Analysis of spider community structure from the canopy of Acacia mangiun. Acta Zoologica Sinica 39 (in Chinese): 374–384.Google Scholar
  34. Lovett J.C. 1992. Main report of the Udzungwa Forest Management Project Identification Mission. Forest and Beekeeping Division, Ministry of Tourism, Natural Resources and Environment, and DANIDA, Dar es Salaam, Tanzania.Google Scholar
  35. Lovett J.C. and Wasser S. 1993. Biogeography and Ecology of the Rainforest of Eastern Africa. Cambridge University Press, Cambridge, UK.Google Scholar
  36. Lowman M.D. and Wittman P.K. 1996. Forest canopies: methods, hypothesis, and future directions. Annual Review of Ecology and Systematics 27: 55–81.Google Scholar
  37. Magurran A.E. 1988. Ecological Diversity and its Measurement. Chapman & Hall, London.Google Scholar
  38. Majer J.D. and Recher H.F. 1988. Invertebrate communities on Western Australian eucalypts: a comparison of branch clipping and chemical knockdown procedures. Australian Journal of Ecology 13: 279–284.Google Scholar
  39. Majer J.D., Recher H.F. and Keals N. 1996. Branchlet shaking: a method for sampling tree canopy arthropods under windy conditions. Australian Journal of Ecology 21: 229–234.Google Scholar
  40. Majer J.D., Recher H.F. and Postle A.C. 1994. Comparison of arthropod species richness in eastern and western Australian canopies: a contribution to the species number debate. Memoirs of the Queensland Museum 36: 121–131.Google Scholar
  41. Martin J.L. 1966. The insect ecology of Red Pine plantations in central Ontario IV. The crown fauna. Canadian Entomologist 98: 10–27.Google Scholar
  42. McKamey S.H. 1999. Biodiversity of tropical Homoptera, with the first data from Africa. American Entomologist 45: 213–222.Google Scholar
  43. Nyffeler M. and Benz G. 1979. Zur Ökologischen Bedeutung der Spinnen der Vegetationsschicht von Getreide-und Rapsfeldern bei Zürich (Schweiz). Zeitschrift für Angewandte Entomologie 87: 348–376.Google Scholar
  44. Ozanne C.M.P. 1996. The arthropod communities of coniferous forest trees. Selbyana 17: 43–49.Google Scholar
  45. Ozanne C.M.P. 1999. A comparison of the canopy arthropod communities of coniferous and broadleaved trees in the United Kingdom. Selbyana 20: 290–298.Google Scholar
  46. Ozanne C.M.P., Speight M.R., Hambler C. and Evans H.F. 2000. Isolated trees and forest patches: patterns in canopy arthropod abundance and diversity in Pinus sylvestris (Scots Pine). Forest Ecology and Management 137: 53–63.Google Scholar
  47. Platnick N.I. 1999. Dimensions of biodiversity: targeting megadiverse groups. In: Cracraft J. and Grifo F.T. (eds), The Living Planet in Crisis: Biodiversity Science and Policy. Columbia University Press, New York, pp. 33–52.Google Scholar
  48. Platnick N.I. and Forster R.R. 1989. A revision of the temperate South American and Australian spiders of the familiy Anapidae (Araneae, Araneoidea). Bulletin of the American Museum of Natural History 190: 1–139.Google Scholar
  49. Recher H.F., Majer J.D. and Ganesh S. 1998. Seasonality of canopy invertebrate communities in eucalypt forests of eastern and western Australia. Australian Journal of Ecology 21: 64–80.Google Scholar
  50. Russell-Smith A. and Stork N.E. 1994. Abundance and diversity of spiders from the canopy of tropical rainforests with particular reference to Sulawesi, Indonesia. Journal of Tropical Ecology 10: 545–558.Google Scholar
  51. Russell-Smith A. and Stork N.E. 1995. Composition of spider communities in the canopies of rainforest trees in Borneo. Journal of Tropical Ecology 11: 223–235.Google Scholar
  52. Samu F. and Lövei G.L. 1995. Species richness of a spider community (Araneae): extrapolation from simulated increasing sampling effort. European Journal of Entomology 92: 633–638.Google Scholar
  53. Scharff N. 1990. Spiders of the family Linyphiidae from the Uzungwa Mountains, Tanzania (Araneae). Entomologica Scandinavica Suppl. 36: 1–95.Google Scholar
  54. Scharff N. 1992. The linyphiid fauna of eastern Africa (Araneae: Linyphiidae)-distribution, diversity and endemism. Biological Journal of the Linnean Society 45: 117–154.Google Scholar
  55. Silva D. 1996. Species composition and community structure of Peruvian rainforest spiders: a case study from a seasonally inundated forest along the Samiria river. Proceedings of the XIIIth International Congress of Arachnology, Geneva, 3-8 September 1995. Revue de Suisse Zoologie,Vol. hors serie, pp. 597–610.Google Scholar
  56. Silva D. and Coddington J.A. 1996. Spiders of Pakitza (Madre de Dios) Peru: species richness and notes on community structure. In: Wilson D.E. and Sandoval A. (eds), The Biodiversity of Pakitza and its Environs. Smithsonian Institution, Washington, DC, pp. 241–299.Google Scholar
  57. Smith E.P. and van Belle G. 1984. Nonparametric estimation of species richness. Biometrics 40: 119–129.Google Scholar
  58. Southwood T.R.E., Moran V.C. and Kennedy C.E.J. 1982. The richness, abundance and biomass of the arthropod communities on trees. Journal of Animal Ecology 51: 635–647.Google Scholar
  59. Sørensen L.L. 2003. Stratification of the spider fauna in a Tanzanian forest. In: Basset Y., Novotny V., Miller S.E. and Kitching R.L. (eds), Arthropods of Tropical Forests: Spatio-Temporal Dynamics and Resource Use in the Canopy. Cambridge University Press, Cambridge, UK, pp. 92–101.Google Scholar
  60. Sørensen L.L., Coddington J.A. and Scharff N. 2002. Inventorying and estimating sub-canopy spider diversity using semi-quantitative sampling methods in an Afromontane forest. Environmental Entomology 31: 319–330.Google Scholar
  61. Stevenson B.G. and Dindal D.L. 1982. Effect of leaf shape on forest litter spiders: community organisation and microhabitat selection of immature Enoplognatha ovata (Cleck) (Theridiidae). Journal of Arachnology 10: 165–178.Google Scholar
  62. Stork N.E. 1987a. Arthropod faunal similarity of Bornean rain forest trees. Ecological Entomology 12:219–226.Google Scholar
  63. Stork N.E. 1987b. Guild structure of arthropods from Bornean rain forest trees. Ecological Entomology 12: 69–80.Google Scholar
  64. Stork N.E. 1988. Insect diversity: facts, fiction and speculation. Biological Journal of the Linnean Society 35: 321–337.Google Scholar
  65. Stork N.E. 1991. The composition of the arthropod fauna of Bornean lowland rain forest trees. Journal of Tropical Ecology 7: 161–180.Google Scholar
  66. Stratton G.E., Uetz G.W. and Dillery D.G. 1979. A comparison of the spiders of three coniferous tree species. Journal of Arachnology 6: 219–226.Google Scholar
  67. Stuntz S. 2001. The influence of epiphytes on arthropods in the tropical forest canopy, Ph.D. Thesis, University of Wurzburg, Wurzburg, Germany (http: / / liste. html).Google Scholar
  68. Turnbull A.L. 1973. Ecology of the true spiders (Araneomorphae). Annual Review of Entomology 18: 305–348.Google Scholar
  69. Uetz G.W. 1991. Habitat structure and spider foraging. In: Bell S.S., McCoy E.D. and Mushinsky H.R. (eds), Habitat Structure. The Physical Arrangement of Objects in Space. Chapman & Hall, London, pp. 325–348.Google Scholar
  70. Watanabe H. 1997. Estimation of arboreal and terrestrial arthropod densities in the forest canopy as measured by insecticide smoking. In: Stork N.E., Adis J. and Didham R.K. (eds), Canopy Arthropods. Chapman & Hall, London, pp. 401–414.Google Scholar
  71. Watanabe H. and Ruaysoongnern S. 1989. Estimation of arboreal arthropod density in a dry evergreen forest in northeastern Thailand. Journal of Tropical Ecology 5: 151–158.Google Scholar

Copyright information

© Kluwer Academic Publishers 2004

Authors and Affiliations

  • Line L. Sørensen
    • 1
  1. 1.Zoological MuseumUniversity of CopenhagenCopenhagen ØDenmark

Personalised recommendations