Abstract
A 3-year study was undertaken on and around a prominent South African mesa to determine its role for grasshoppers in a sea of grazed flatlands. The number of grasshopper species and individuals on the summit, slopes and flatlands varied significantly in relation to measured environmental variables. The summit, through inaccessibility to livestock grazing, was effectively a conservation refugium for one highly responsive grasshopper species, Orthochtha dasycnemis. There was no significant difference in species richness between years of sampling, although there were significant variations in grasshopper abundance between years. The difference in rainfall between years was significant and appeared to be the key factor influencing grasshopper population dynamics. This study clearly shows that a mesa can act as a conservation island and refugium supporting an insect assemblage that would be otherwise altered by heavy livestock grazing on the surrounding flatlands. This summit assemblage was strongly linked with those on the slopes, and is determined by low grazing intensity and associated soil and vegetation structure.
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References
A.J. Armstrong H.J. van Hensbergen (1999) ArticleTitleIdentification of priority regions for animal conservation in afforestable montane grasslands of the northern Eastern Cape ProvinceSouth Africa Biological Conservation 87 93–103 Occurrence Handle10.1016/S0006-3207(98)00030-5
W. Barthlott A. Gröger S. Porembski (1993) ArticleTitleSome remarks on the vegetation of tropical inselbergs: diversity and ecological differentiation Biogeògraphica 69 105–124
M. Begon J.L. Harper C.R. Townsend (1990) Ecology: Individuals, Populations and Communities Blackwell Oxford
G.E. Belovsky J.B. Slade (1995) ArticleTitleDynamics of two montana grasshopper populations: relationships among weatherfood abundance and interspecific competition Oecologia 101 383–396 Occurrence Handle10.1007/BF00328826
H.E. Braker (1989) ArticleTitleEvolution and ecology of oviposition on host plants by acridid grasshoppers Biological Journal of the Linnean Society 38 389–406
J.L. Capinera T.S. Sechrist (1982) ArticleTitleGrasshopper (Acrididae)-host plant associations: response of grasshopper populations to cattle grazing intensity Canadian Entomologist 114 1055–1062
B.Q. Chambers M.J. Samways (1998) ArticleTitleGrasshopper response to a 40-year experimental burning and mowing regimewith recommendations for invertebrate conservation management Biodiversity and Conservation 7 985–1012
M.A. Chappell D.W. Whitman (1990) Grasshopper thermoregulation R.F. Chapman A. Joern (Eds) Biology of Grasshoppers Wiley New York 143–172
R.F. Chapman W.W. Page A.G. Cook (1979) ArticleTitleA study of population changes in the grasshopper Zonocerus variegatusin southern Nigeria Journal of Animal Ecology 48 247–270
J.P. Curry (1994) Grassland Invertebrates. Ecology, Influence on Soil Fertility and Effects on Plant Growth Chapman and Hall UK
R. Daubenmire (1965) ArticleTitleA canopy coverage method of vegetation analysis Northwest Sci. 33 43–46
W.R.J. Dean M.T. Hoffman M.E. Meadows S.J. Milton (1995) ArticleTitleDesertification in the semi-arid KarooSouth Africa: review and reassessment Journal of Arid Environments 30 247–264 Occurrence Handle10.1016/S0140-1963(05)80001-1
J.P. Dempster (1963) ArticleTitleThe population dynamics of grasshoppers and locusts Biological Reviews 38 490–529
P.C. Eterovick J.E.C. Figueira J. Vasconcellosento (1997) ArticleTitleCryptic coloration and choice of escape microhabitats by grasshoppers (Orthoptera: Acrididae) Biological Journal of the Linnean Society 61 485–499
M. Fogden P. Fogden (1974) Animals and Their Colours Crown New York
M.V. Gandar (1982) ArticleTitleThe dynamics and trophic ecology of grasshoppers (Acridoidea) in a South African savanna Oecologia 54 370–378 Occurrence Handle10.1007/BF00380006
M.V. Gandar (1983) Ecological notes and annotated checklist of the grasshoppers (Orthoptera: Acrididae) of the Savanna Ecosystem Project Study AreaNylsvley South African National Scientific Programmes Pretoria
S. Gebeyehu M.J. Samways (2002) ArticleTitleGrasshopper assemblage response to a restored national park (Mountain Zebra National Park, South Africa) Biodiversity and Conservation 11 283–304 Occurrence Handle10.1023/A:1014514007744
N.D. Holmes D.S. Smith A. Johnston (1979) ArticleTitleEffect of grazing by cattle on the abundance of grasshoppers on fescue grassland Journal of Range Management 32 310–311
F.B. Isely (1937) ArticleTitleSeasonal succession, soil relations, numbers, and regional distribution of northeastern Texas acridians Ecological Monographs 7 317–344
A. Joern (1979) ArticleTitleResource utilization and community structure in assemblages of arid grassland grasshoppers (Orthoptera: Acrididae) Transactions of the American Entomological Society 105 253–300
W.P. Kemp T.M. Kalaris W.F. Quimby (1989) ArticleTitleRangeland grasshopper (Orthoptera: Acrididae) spatial variability: macroscale population assessment Journal of Economic Entomology 82 1270–1276
W.P. Kemp (1992) ArticleTitleRangeland grasshoppers (Orthoptera: Acrididae) community structure: a working hypothesis Environmental Entomology 21 461–470
W.P. Kemp D. Brian (1993) ArticleTitleDensity dependence in rangeland grasshoppers (Orthoptera: Acrididae) Oecologia 96 1–8 Occurrence Handle10.1007/BF00318023
D.J. Kotze M.J. Samways (1999) ArticleTitleSupport for the multi-taxa approach in biodiversity assessmentas shown by epigaeic invertebrates in an afromontane forest archipelago Journal of Insect Conservation 3 125–143 Occurrence Handle10.1023/A:1009660601372
T. Kisebenedek (1995) ArticleTitleThe effects of sheep grazing on the community structure of grasshoppers (Orthoptera) Folia Entomologica Hungarica 56 45–46
J.H. Lawton D.E. Bignell B. Bolton G.F. Blomers P. Eggleton P.M. Hammond M. Hodda R.D. Holt T.B. Larsen N.A. Mawdsley N.E. Stork D.S. Srivastava A.D. Watt (1998) ArticleTitleBiodiversity inventories, indicator taxa and effects of habitat modification in tropical forest Nature 391 72–76 Occurrence Handle10.1038/34166 Occurrence Handle1:CAS:528:DyaK1cXjvFansg%3D%3D
J.A. Ludwig J.F. Reynolds (1988) Statistical Ecology. A Primer on Methods and Computing Wiley New York
R. Pickford (1963) ArticleTitleWheat crops and native prairie in relation to the nutritional ecology of Camnula pellucida (Scudder) (Orthoptera: Acrididae) in Saskatchewan Canadian Entomologist 95 764–770
Popov G.B. 1958. Ecological studies on oviposition by swarms of the Desert Locust (Schistocerca gregaria Forskål) in eastern Africa. Anti-locust Bulletin No. 31.
L. Prendini J.L. Theron K. Merwe Particlevan der N. Owen-Smith (1996) ArticleTitleAbundance and guild structure of grasshoppers (Orthoptera: Acridoidea) in communally grazed and protected savanna South African Journal of Zoology 31 12–30
M.A. Quinn D.D. Walgenbach (1990) ArticleTitleInfluence of grazing history on the community structure of grasshoppers of a mixed grass-prairie Environmental Entomology 19 1756–1766
C.F. Rodell (1977) ArticleTitleA grasshopper model for a grassland ecosystem Ecology 58 227–245
M.J. Samways (1990) ArticleTitleLand forms and winter habitat refugia in the conservation of montane grasshoppers in South Africa Conservation Biology 4 375–382 Occurrence Handle10.1111/j.1523-1739.1990.tb00311.x
M.J. Samways S.D. Moore (1991) ArticleTitleInfluence of exotic conifer patches on grasshopper (Orthoptera) assemblages in a grassland matrix at a recreational resortNatal, South Africa Conservation Biological 5 117–137
T.R.E. Southwood H.F. Emden Particlevan (1967) ArticleTitleA comparison of the fauna of cut and uncut grasslands Zeitschrift für Angewandte Entomologie 60 188–198
D.A.B. Stewart (1997) ArticleTitleEconomic losses in several crops following damage by the African migratory locustLocustana pardalina migratorioides (Reiche and Firmaire) (Orthoptera: Acrididae), in the Northern Province of South Africa African Entomology 5 167–170
C.J.F. Ter Braak (1986) ArticleTitleCannonical correspondence analysis: A new eigenvector technique for multivariate direct gradient analysis Ecology 67 1167–1179
C.J.F. Ter Braak C.W.N. Looman (1995) Regression R.H.G. Jongman C.J.F. Ter Braak O.F.R. Tongern ParticleVan (Eds) Data analysis in Community and Landscape Ecology Cambridge University Press Cambridge 29–77
C.J.F. Ter Braak P. Smilauer (1998) CANOCO Reference Manual and User's Guide to Canoco For Windows: Software For Canonical Community Ordination (version 4). Microcomputer Power Ithaca New York
C.R. Twidale (1971) Structural Landforms: Landforms Associated With Granitic Rocks, Faults, and Folded Strata Massachusetts Cambridge
B.P. Uvarov (1977) Grasshoppers and Locusts, Vol II Centre for Overseas Pest Research London
L.J. Vitt S.S. Sartorius T.C.S. Avilapires M.C. Esposito D.B. Miles (2000) ArticleTitleNiche segregation among sympatric amazonian teiid lizards Oecologia 122 410–420 Occurrence Handle10.1007/s004420050047
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Gebeyehu, S., Samways, M.J. Conservation Refugium Value of a Large Mesa for Grasshoppers in South Africa. Biodivers Conserv 15, 717–734 (2006). https://doi.org/10.1007/s10531-004-1062-8
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DOI: https://doi.org/10.1007/s10531-004-1062-8