Skip to main content

Advertisement

SpringerLink
Log in

Changes in arthropod diversity along a land use driven gradient of shrub cover in savanna rangelands: identification of suitable indicators

  • Original Paper
  • Published:
Biodiversity and Conservation Aims and scope Submit manuscript

Abstract

Shrub encroachment linked to heavy grazing has dramatically changed savanna landscapes, and is a major form of rangeland degradation. Our understanding of how shrub encroachment affects arthropod communities is poor, however. Here, we investigate the effects of shrub encroachment on abundance and diversity of ground-dwelling (wingless) arthropods at varying levels of shrub cover in the southern Kalahari. We also ascertain if invertebrate assemblage composition changes with habitat structure and identify which aspects of habitat structure (e.g., grass cover, herbaceous plant cover, shrub density) correlate most strongly with these changes. Ant, scorpion and dung beetle abundance increased with shrub cover, whereas grasshoppers and solifuges declined. Spider and beetle abundance exhibited hump-shaped relationships with shrub cover. RTU richness within orders either mirrored abundances, or exhibited no trend. Shrub density was the habitat component most correlated with similarities between invertebrate assemblages. Ground-dwelling arthropods showed clear shifts in species assemblage composition at a similarity level of 65% according to shrub density. Changes in indicator species showed that within the Tenebrionidae (darkling beetles), certain species respond positively to shrub thickening, replacing other species within the Family. Small-bodied, wingless Scarabaeidae (dung beetles) tended to increase with increased shrub density and three species emerged as significant indicators of more thickened habitats, although this might be a response to greater dung availability, rather than habitat structure itself. We conclude that because ground-dwelling invertebrates showed such clear responses in species assemblage composition, they present excellent candidates for use as indicator species in further studies into bush encroachment.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

References

  • Archer S, Schimel DS, Holland EA (1995) Mechanisms of shrubland expansion—land use, climate or Co-2. Clim Change 29:91–99. doi:10.1007/BF01091640

    Article  Google Scholar 

  • Blaum N, Wichmann M (2007) Short term transformation of matrix into hospitable habitat facilitates gene flow and mitigates fragmentation. J Anim Ecol 76:1116–1127. doi:10.1111/j.1365-2656.2007.01283.x

    Article  PubMed  Google Scholar 

  • Blaum N, Rossmanith E, Fleissner G, Jeltsch F (2007a) The conflicting importance of shrubby landscape structures for the reproductive success of the yellow mongoose (Cynictis penicillata). J Mammal 88:194–200. doi:10.1644/05-MAMM-A-314R3.1

    Article  Google Scholar 

  • Blaum N, Rossmanith E, Jeltsch F (2007b) Land use affects rodent communities in Kalahari savannah rangelands. Afr J Ecol 45:189–195. doi:10.1111/j.1365-2028.2006.00696.x

    Article  Google Scholar 

  • Blaum N, Rossmanith E, Popp A, Jeltsch F (2007c) Shrub encroachment affects mammalian carnivore abundance and species richness in semiarid rangelands. Acta Oecol 31:86–92. doi:10.1016/j.actao.2006.10.004

    Article  Google Scholar 

  • Blaum N, Rossmanith E, Schwager M, Jeltsch F (2007d) Responses of mammalian carnivores to land use in arid savanna rangelands. Basic Appl Ecol 8:552–564. doi:10.1016/j.baae.2006.09.003

    Article  Google Scholar 

  • Blaum N (in press a) Seasonal differences in spatial distribution of small carnivores in fragmented savannah landscapes. Afr J Ecol. doi:10.1111/j.1365-2028.2008.00958.x

  • Blaum N, Tietjen B, Rossmanith E (in press b) The impact of livestock husbandry on small and medium sized carnivores in Kalahari savannah rangelands. J Wildl Manag

  • Blaum N, Engeman RM, Wasiolka B, Rossmanith E (2008) Indexing small mammalian carnivores in the southern Kalahari, South Africa. Wildl Res 35:72–79. doi:10.1071/WR07023

    Article  Google Scholar 

  • Cabral AC, De Miguel JM, Rescia AJ, Schmitz MF, Pineda FD (2003) Shrub encroachment in Argentinean savannas. J Veg Sci 14:145–152. doi:10.1658/1100-9233(2003)014[0145:SEIAS]2.0.CO;2

    Article  Google Scholar 

  • Cagnolo L, Molina SI, Valladares GR (2002) Diversity and guild structure of insect assemblages under grazing and exclusion regimes in a montane grassland from central Argentinia. Biodivers Conserv 11:407–420. doi:10.1023/A:1014861906082

    Article  Google Scholar 

  • Chapin FS, Zavaleta ES, Eviner VT, Naylor RL, Vitousek PM, Reynolds HL, Hooper DU, Lavorel S, Sala OE, Hobbie SE, Mack MC, Diaz S (2000) Consequences of changing biodiversity. Nature 405:234–242. doi:10.1038/35012241

    Article  PubMed  CAS  Google Scholar 

  • Churchill TB, Ludwig JA (2004) Changes in spider assemblages along grassland and savanna grazing gradients in northern Australia. Rangel J 26:3–16. doi:10.1071/RJ04001

    Article  Google Scholar 

  • Cingolani AM, Noy-Meir I, Diaz S (2005) Grazing effects on rangeland diversity, a synthesis of contemporary models. Ecol Appl 15:757–773. doi:10.1890/03-5272

    Article  Google Scholar 

  • Clarke KR, Ainsworth M (1993) A method of linking multivariate community structure to environmental variables. Mar Ecol Prog Ser 92:205–219. doi:10.3354/meps092205

    Article  Google Scholar 

  • Clarke KR, Gorley RN (2001) Plymouth routines in multivariate ecological research (PRIMER). Primer-E Ltd, Plymouth

    Google Scholar 

  • Dean WRJ, Macdonald IAW (1994) Historical changes in stocking rates of domestic livestock as a measure of semi-arid, and arid rangeland degradation in the Cape Province, South Africa. J Arid Environ 26:281–298. doi:10.1006/jare.1994.1030

    Article  Google Scholar 

  • Dean WRJ, Milton SJ (1995) Plant and invertebrate assemblages on old fields in the arid southern Karoo, South Africa. Afr J Ecol 33:1–13. doi:10.1111/j.1365-2028.1995.tb00777.x

    Article  Google Scholar 

  • Duelli P, Obrist MK, Schmatz DR (1999) Biodiversity evaluation in agricultural landscapes: above-ground insects. Agric Ecosyst Environ 74:33–64. doi:10.1016/S0167-8809(99)00029-8

    Article  Google Scholar 

  • Dufrêne M, Legendre P (1997) Species assemblages and indicator species: the need for a flexible asymmetrical approach. Ecol Monogr 67:345–366

    Google Scholar 

  • Ehrlich PR (1994) Biodiversity and ecosystem function: need we know more? In: Schulze E-D, Mooney HA (eds) Biodiversity and ecosystem function. Springer, Berlin

    Google Scholar 

  • Ewers MR, Didham RK (2006) Confounding factors in the detection of species responses to habitat fragmentation. Biol Rev Camb Philos Soc 81:117–142. doi:10.1017/S1464793105006949

    PubMed  Google Scholar 

  • Fabricius C, Burger M, Hockey PAR (2003) Comparing biodiversity between protected areas and adjacent rangeland in xeric succulent thicket, South Africa: arthropods and reptiles. J Appl Ecol 40:392–403

    Google Scholar 

  • Gandar MV (1982) Trophic ecology and plant herbivore energetics. Ecol Stud 42:514–534

    Google Scholar 

  • Greenslade PJM (1964) Pitfall trapping as a method for studying populations of Carabidae (Coleoptera). J Anim Ecol 33:1–310

    Google Scholar 

  • Greenslade PJM (1992) Conserving invertebrate diversity in agricultural, forestry and natural ecosystem in Australia. Agric Ecosyst Environ 40:297–312. doi:10.1016/0167-8809(92)90099-W

    Article  Google Scholar 

  • Herremans M (1998) Conservation status of birds in Botswana in relation to land use. Biol Conserv 86:139–160. doi:10.1016/S0006-3207(98)00016-0

    Article  Google Scholar 

  • Hill JK, Hamer KC, Lace LA, Banham WMT (1995) Effects of selective logging on tropical forest butterflies on Buru, Indonesia. J Appl Ecol 32:754–760. doi:10.2307/2404815

    Article  Google Scholar 

  • Hoffmann BD (2000) Changes in ant species composition and community organisation along grazing gradients in semi-arid rangelands of the northern Territory. Rangel J 22:171–189. doi:10.1071/RJ0000171

    Article  Google Scholar 

  • Jankielsohn A, Scholtz CH, Louw SV (2001) Effect of habitat transformation on dung beetle assemblages: a comparison between a South African nature reserve and neighboring farms. Environ Entomol 30:474–483

    Article  Google Scholar 

  • Janzen DH (1987) Insect diversity of a Costa Rican dry forest: why keep it and how? Biol J Linn Soc Lond 30:343–356. doi:10.1111/j.1095-8312.1987.tb00307.x

    Article  Google Scholar 

  • Jeltsch F, Milton SJ, Dean WRJ, Van Rooyen N (1997) Analysing shrub encroachment in the southern Kalahari a grid-based modelling approach. J Appl Ecol 34:1497–1508. doi:10.2307/2405265

    Article  Google Scholar 

  • Kraaij T, Ward D (2006) Effects of rain, nitrogen, fire and grazing on tree recruitment and early survival in bush-encroached savanna, South Africa. Plant Ecol 186:235–246. doi:10.1007/s11258-006-9125-4

    Article  Google Scholar 

  • Krell FT (2004) Parataxonomy vs. taxonomy in biodiversity studies—pitfalls and applicability of ‘morphospecies’ sorting. Biodivers Conserv 13:795–812. doi:10.1023/B:BIOC.0000011727.53780.63

    Article  Google Scholar 

  • Leistner OA (1967) The plant ecology of the southern Kalahari. Mem Bot Surv S Afr 38:1–171

    Google Scholar 

  • Lobo JM, Hortal J, Cabrero-Sanudo FJ (2006) Regional and local influence of grazing activity on the diversity of a semi-arid dung beetle community. Divers Distrib 12:111–123. doi:10.1111/j.1366-9516.2006.00194.x

    Article  Google Scholar 

  • MacArthur RH, Wilson OE (1967) The theory of island biogeography. Princeton University Press, Princeton

    Google Scholar 

  • Mazía C, Chaneton EJ, Kitzberger T (2006) Small-scale habitat use and assemblage structure of ground-dwelling beetles in a Patagonian shrub steppe. J Arid Environ 67:177–194. doi:10.1016/j.jaridenv.2006.02.006

    Article  Google Scholar 

  • McCune B, Grace JB (2002) Analysis of ecological communities. MjM Software Design, Gleneden Beach, OR

    Google Scholar 

  • McGeogh MA, van Rensburg BJ, Botes A (2002) The verification and application of bioindicators: a case study of dung beetles in a savanna ecosystem. J Appl Ecol 39:661–672. doi:10.1046/j.1365-2664.2002.00743.x

    Article  Google Scholar 

  • Meik JM, Jeo RM, Mendelson III Jr, Jenks KE (2002) Effects of bush encroachment on an assemblage of diurnal lizard species in central Namibia. Biol Conserv 106:29–36. doi:10.1016/S0006-3207(01)00226-9

    Article  Google Scholar 

  • Milton SJ, Dean WRJ (1995) How useful is the keystone species concept, and can it be applied to Acacia erioloba in the Kalahari Desert? Z Okologie Naturschutz 4:147–156

    Google Scholar 

  • Moleele NM, Perkins JS (1998) Encroaching woody plant species and boreholes, is cattle density the main driving factor in the Olifants Drift communal grazing lands, south-eastern Botswana? J Arid Environ 40:245–253. doi:10.1006/jare.1998.0451

    Article  Google Scholar 

  • Mucina L, Rutherford MC, Powrie LW (eds) (2005) Vegetation map of South Africa, Lesotho and Swaziland, 1:1000000 scale sheet maps. South African National Biodiversity Institute, Pretoria

    Google Scholar 

  • Oliver I, Beattie AJ (1993) A possible method for the rapid assessment of biodiversity. Conserv Biol 7:562–568. doi:10.1046/j.1523-1739.1993.07030562.x

    Article  Google Scholar 

  • Rice WR (1989) Analyzing tables of statistical tests. Evol Int J Org Evol 43:223–225. doi:10.2307/2409177

    Google Scholar 

  • Rivers-Moore JL, Samways MJ (1996) Game and cattle trampling, and impacts of human dwellings on arthropods at a game park. Biodivers Conserv 5:1545–1557. doi:10.1007/BF00052115

    Article  Google Scholar 

  • Samways MJ (1994) Insect conservation biology. Chapman and Hall, London

    Google Scholar 

  • Sankaran M, Hanan NP, Scholes RJ, Ratnam J, Augustine DJ, Cade BS, Gignoux J, Higgings SI, Le Roux X, Ludwig F, Ardo J, Banyikwa F, Bronn A, Bucini G, Caylor KK, Coughenour MB, Diouf A, Ekaya W, Feral CJ, February EC, Frost PGH, Hiernaux P, Hrabar H, Metzger KL, Prins HHT, Ringrose S, Sea W, Tews J, Worden J, Zambatis N (2005) Determinants of woody cover in African savannas. Nature 438:846–849. doi:10.1038/nature04070

    Article  PubMed  CAS  Google Scholar 

  • Scholes RJ, Walker BH (1993) An African savanna synthesis of the Nylsvley study. Cambridge University Press, Cambridge

    Google Scholar 

  • Scholtz CH, Holm E (1989) Insects of southern Africa. Butterworths, Durban

    Google Scholar 

  • Schowalter TD (2006) Insect ecology: an ecosystem approach, 2nd edn. Elsevier, London

    Google Scholar 

  • Seastedt TR, Crossley DA (1984) The influence of arthropods on ecosystems. Bioscience 34:157–161. doi:10.2307/1309750

    Article  Google Scholar 

  • Seymour CL (2006) The influence of size and density on Acacia erioloba’s role as a keystone species in the southern Kalahari. Dissertation, University of Cape Town

  • Seymour CL, Dean WRJ (1999) Effects of heavy grazing on invertebrate assemblages in the Succulent Karoo, South Africa. J Arid Environ 43:267–286. doi:10.1006/jare.1999.0552

    Article  Google Scholar 

  • Siemann E, Tilman D, Haarstad J, Ritchi M (1998) Experimental tests of the dependence of arthropod diversity on plant diversity. Am Nat 152:738–750. doi:10.1086/286204

    Article  PubMed  CAS  Google Scholar 

  • Skarpe C (1990) Shrub layer dynamics under different herbivore densities in an arid savanna, Botswana. J Appl Ecol 27:873–885. doi:10.2307/2404383

    Article  Google Scholar 

  • Skarpe C (1991) Spatial patterns and dynamics of woody vegetation in an arid savanna. J Veg Sci 2:565–572. doi:10.2307/3236039

    Article  Google Scholar 

  • Spitzer K, Jaros J, Havelka J, Leps J (1997) Effect of small-scale disturbance on butterfly communities of an Indochinese montane rainforest. Biol Conserv 80:9–15. doi:10.1016/S0006-3207(96)00079-1

    Article  Google Scholar 

  • Steenkamp HE, Chown SL (1996) Influence of dense stands of an exotic tree, Prosopis glandulosa Benson, on a savanna dung beetle (Coleoptera: Scarabaeinae) assemblage in southern Africa. Biol Conserv 78:301–311. doi:10.1016/S0006-3207(96)00047-X

    Article  Google Scholar 

  • Tews J, Brose U, Grimm V, Tielbörger K, Wichmann MC, Schwager M, Jeltsch F (2004) Animal species diversity driven by habitat heterogeneity/diversity: the importance of keystone structures. J Biogeogr 31:79–92

    Google Scholar 

  • Tews J, Milton SJ, Esther A, Jeltsch F (2006) Linking a population model with a landscape model: assessing the impact of land use and climate change on savanna shrub cover dynamics. Ecol Modell 195:219–228. doi:10.1016/j.ecolmodel.2005.11.025

    Article  Google Scholar 

  • Thiele T, Jeltsch F, Blaum N (2008) Importance of woody vegetation for foraging site selection in the southern Pied Babbler (Turdoides bicolor) under two different land use regimes. J Arid Environ 72:471–482. doi:10.1016/j.jaridenv.2007.06.011

    Article  Google Scholar 

  • Van Rooyen N, Bredenkamp G, Theron GK (1991) Kalahari vegetation veldt condition trends and ecological status of species. Koedoe 34:61–72

    Google Scholar 

  • Wasiolka B (2003) Ecological functions of shrubby vegetation structures for faunal diversity in the southern Kalahari. MSc Thesis, University of Potsdam

  • Wettenstein W, Schmid B (1999) Conservation of arthropod diversity in montane wetlands: effect of altitude, habitat quality and habitat fragmentation on butterflies and grasshoppers. J Appl Ecol 36:363–373. doi:10.1046/j.1365-2664.1999.00404.x

    Article  Google Scholar 

  • Wiens JA, Milne BT (1989) Scaling of “landscapes” in landscape ecology, or, landscape ecology from a beetle’s perspective. Landsc Ecol 3:87–96. doi:10.1007/BF00131172

    Article  Google Scholar 

  • Zar JH (1998) Biostatistical analysis, 4th edn. Prentice-Hall, Upper Saddle River

    Google Scholar 

Download references

Acknowledgments

The work was funded by the German Ministry of Education and Research (BMBF) in the framework of BIOTA Southern Africa (01LC0024). We gratefully thank the Northern Cape Nature Conservation for research permission in the study area (permit numbers: 197/2001, 294/2002). An anonymous reviewer provided helpful comments on an earlier version of the manuscript.

Author information

Authors and Affiliations

  1. Department of Plant Ecology and Nature Conservation, Institute of Biochemistry and Biology, University of Potsdam, Maulbeerallee 2, 14469, Potsdam, Germany

    Niels Blaum, Eva Rossmanith & Florian Jeltsch

  2. Applied Biodiversity Research, Kirstenbosch Research Centre, South African National Biodiversity Institute, Private Bag X7, Claremont, 7735, South Africa

    Colleen Seymour

  3. Department of Ecology, Institute of Zoology, University of Mainz, Johann-Joachim Becherweg 13, 55099, Mainz, Germany

    Monika Schwager

Authors
  1. Niels Blaum
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Colleen Seymour
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Eva Rossmanith
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Monika Schwager
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Florian Jeltsch
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Niels Blaum.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Blaum, N., Seymour, C., Rossmanith, E. et al. Changes in arthropod diversity along a land use driven gradient of shrub cover in savanna rangelands: identification of suitable indicators. Biodivers Conserv 18, 1187–1199 (2009). https://doi.org/10.1007/s10531-008-9498-x

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10531-008-9498-x

Keywords

Search

Navigation