Land-use degradation and climate change are well-known drivers of biodiversity loss, but little information is available about their potential interaction. Here, we focus on the effects of land-use and precipitation on ant diversity in cacao agroforestry. In Central Sulawesi, Indonesia, we selected 16 cacao agroforestry plots with a shaded vs. unshaded plot in each of eight villages differing in precipitation (1032–2051 mm annual rainfall). On each plot, 10 cacao trees with similar size and age (7–10 years) were selected for hand collection of ants on each cacao tree and the soil surface. In total, we found 80 ant species belonging to five subfamilies. Land-use intensification (removal of shade trees) and precipitation had no effect on species richness of ants per cacao tree (alpha diversity) and, in an additive partitioning approach, within-plot beta diversity. However, higher precipitation (but not shade) significantly increased ant species dissimilarity across cacao trees within a plot, with ant species showing contrasting responses to precipitation. Reduced precipitation causing drought stress appeared to contribute to convergence of ant community structure, presumably via reduced heterogeneity in cacao tree growth. In conclusion, reduced precipitation greatly influenced ant community dissimilarity and appeared to be more important for ant community structure than land-use intensification.
References
[1]
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.; et al. Biodiversity-Global biodiversity scenarios for the year 2100. Science 2000, 287, 1770–1774, doi:10.1126/science.287.5459.1770.
[2]
Lovejoy, T.E. Climate change. In Conservation Biology for All; Sodhi, N.S., Ehrlich, P.R., Eds.; Oxford University Press: Oxford, UK, 2010; pp. 153–162.
[3]
Hellmann, J.J.; Byers, J.E.; Bierwagen, B.G.; Dukes, J.S. Five potential consequences of climate change for invasive species. Conserv. Biol. 2008, 22, 534–543, doi:10.1111/j.1523-1739.2008.00951.x.
[4]
Tylianakis, J.M.; Didham, R.K.; Bascompte, J.; Wardle, D.A. Global change and species interactions in terrestrial ecosystems. Ecol. Lett. 2008, 11, 1351–1363, doi:10.1111/j.1461-0248.2008.01250.x.
[5]
Gornall, J.; Betts, R.; Burke, E.; Clark, R.; Camp, J.; Willett, K.; Wiltshire, A. Implications of climate change for agricultural productivity in the early twenty-first century. Philos. Trans. R. Soc. Lond. Ser. B 2010, 365, 2973–2989, doi:10.1098/rstb.2010.0158.
Clough, Y.; Barkmann, J.; Juhrbandt, J.; Kessler, M.; Wanger, T.C.; Anshary, A.; Buchori, D.; Cicuzza, D.; Darras, K.; Putra, D.D.; et al. Combining high biodiversity with high yields in tropical agroforests. Proc. Natl. Acad. Sci. USA 2011, 108, 8311–8316.
[9]
Wanger, T.C.; Rauf, A.; Schwarze, S. Pesticides and tropical biodiversity. Front. Ecol. Environ. 2010, 8, 178–179.
[10]
Philpott, S.M.; Armbrecht, I. Biodiversity in tropical agroforests and the ecological role of ants and ant diversity in predatory function. Ecol. Entomol. 2006, 31, 369–377, doi:10.1111/j.1365-2311.2006.00793.x.
[11]
Bos, M.M.; Steffan-Dewenter, I.; Tscharntke, T. The contribution of cacao agroforests to the conservation of lower canopy ant and beetle diversity in Indonesia. Biodivers. Conserv. 2007, 16, 2429–2444, doi:10.1007/s10531-007-9196-0.
[12]
Wielgoss, A.; Tscharntke, T.; Buchori, D.; Fiala, B.; Clough, Y. Temperature and a dominant dolichoderine ant species affect ant diversity in Indonesian cacao plantations. Agric. Ecosyst. Environ. 2010, 135, 253–259, doi:10.1016/j.agee.2009.10.003.
[13]
Bestelmeyer, B.T.; Agosti, D.; Alonso, L.E.; Brand？o, C.R.F.; Brown, W.L., Jr.; Delabie, J.H.C.; Silvestre, R. Field techniques for the study of ground-dwelling ants: an overview, description, and evaluation. In Ants: Standard Methods for Measuring and Monitoring Biodiversity; Agosti, D., Majer, J.D., Alonso, L.E., Schultz, T.R., Eds.; Smithsonian Institution Press: Washington, DC, USA, 2000; pp. 122–144.
[14]
Bolton, B. Identification Guide to the Ant Genera of the World; Harvard University Press: Cambridge, UK, 1994; p. 222.
[15]
Lattke, J.E. Specimen processing: building and curating an ant collection. In Ants: Standard Methods for Measuring and Monitoring Biodiversity; Agosti, D., Majer, J.D., Alonso, L.E., Schultz, T.R., Eds.; Smithsonian Institution Press: Washington, DC, USA, 2000; pp. 155–171.
[16]
Antweb. Available online: http://www.antweb.org (accessed on 20 January 2010).
[17]
Colwell, R.K.; Coddington, J.A. Estimating terrestrial biodiversity through extrapolation. Philos. Trans. R. Soc. Lond. Ser. B 1994, 345, 101–118, doi:10.1098/rstb.1994.0091.
[18]
Mantel, N. The detection of disease clustering and a generalized regression approach. Cancer Res. 1967, 27, 209–220.
[19]
Legendre, P.; Legendre, L. Numerical ecology, 2nd English ed.; Elsevier: Dordrecht, The Netherlands, 1998.
[20]
Gering, J.C.; Crist, T.O. The alpha-beta-regional relationship: providing new insights into local-regional patterns of species richness and scale dependence of diversity components. Ecol. Lett. 2002, 5, 433–444, doi:10.1046/j.1461-0248.2002.00335.x.
[21]
R Development Core Team. R: A Language and Environment for Statistical Computing; R Foundation for Statistical Computing: Vienna, Austria, 2011.
[22]
Delsinne, T.; Roisin, Y.; Herbauts, J.; Leponce, M. Ant diversity along a wide rainfall gradient in the Paraguayan dry Chaco. J. Arid Environ. 2010, 74, 1149–1155, doi:10.1016/j.jaridenv.2010.03.014.
[23]
Dunn, R.R.; Agosti, D.; Andersen, A.N.; Arnan, X.; Bruhl, C.A.; Cerdá, X.; Ellison, A.M.; Fisher, B.L.; Fitzpatrick, M.C.; Gibb, H.; et al. Climatic drivers of hemispheric asymmetry in global patterns of ant species richness. Ecol. Lett. 2009, 12, 324–333, doi:10.1111/j.1461-0248.2009.01291.x.
[24]
Dunn, R.R.; Guenard, B.; Weiser, M.D.; Sanders, N.J. Geographic gradients. In Ant Ecology; Lach, L., Parr, C.L., Abbott, K.L., Eds.; Oxford University Press: New York, NY, USA, 2010; pp. 38–58.
[25]
Andersen, A.N. Global ecology of rainforest ants: functional groups in relation to environmental stress and disturbance. In Ants: Standard Methods for Measuring and Monitoring Biodiversity; Agosti, D., Majer, J.D., Alonso, L.E., Schultz, T.R., Eds.; Smithsonian Institution Press: Washington, DC, USA, 2000; pp. 25–34.
[26]
Andersen, A.N. A classification of Australian ant communities, based on functional groups which parallel plant life-forms in relation to stress and disturbance. J. Biogeogr. 1995, 22, 15–29, doi:10.2307/2846070.
[27]
MacArthur, R.; Levins, R. The limiting similarity, convergence, and divergence of coexisting species. Am. Nat. 1967, 101, 377–385.
[28]
Brown, W.L., Jr. Diversity of ants. In Ants: Standard Methods for Measuring and Monitoring Biodiversity; Agosti, D., Majer, J.D., Alonso, L.E., Schultz, T.R., Eds.; Smithsonian Institution Press: Washington, DC, USA, 2000; pp. 45–79.
[29]
Gerold, G.; Leemhuis, C. Effects of “ENSO-events” and rainforest conversion on river discharge in Central Sulawesi (Indonesia). In Tropical Rainforests and Agroforests under Global Change: Ecological and Socio-economic Valuations; Tscharntke, T., Leuschner, C., Veldkamp, E., Faust, H., Guhardja, E., Bidin, A., Eds.; Springer-Verlag: Berlin, 2010; pp. 327–350.
[30]
McGlynn, T.P. The worldwide transfer of ants: geographical distribution and ecological invasions. J. Biogeogr. 1999, 26, 535–548, doi:10.1046/j.1365-2699.1999.00310.x.
