We examined the relationship between seasonal livestock grazing (late summer and late winter) and the abundance of two ant species, Dorymyrmex insana and Forelius pruniosus, on three types of plants (mesquite shrubs, snakeweed sub-shrubs, and mixed grasses) dominated by black grama (Bouteloua eriopoda). Stocking rates were adjusted to remove 75% of the available forage. Since Chihuahuan Desert grasslands are not in transition to shrublands, the grasses and some herbaceous plants are the only available forage. We hypothesized that neither rainfall nor cattle grazing would affect the abundance of these ants on mesquite (Prosipis glandulosa) or snakeweed (Gutierrezia sarothrae). Linear regressions of monsoon rainfall on mesquite (Prosopis glandulosa) produced an r2 nearly equal to that with the annual precipitation. Monsoon rainfall on the evergreen sub-shrub, Gutierrezia sarothrae, resulted in June-July rainfall accounting for 47% - 83% of the variation in densities of D. insana on snakeweed. The number of D. insana was more than double the number of F. pruinosus on grasses, mesquite, and snakeweed. There were significant reductions in the abundance of F. pruinosus on the grass in the grazed plots; each year the plots were grazed. There were no significant effects of grazing on the abundance of either of the ant species sampled from G. sarothrae canopies. There were significantly fewer D. insana on mesquite in summer grazed plots than on P. glandulosa in winter grazed and ungrazed plots in the second and third years of grazing. Pre-grazing effects were compromised by the high annual (more than double) precipitation.
References
[1]
Holldobler, B. and Wilson, E.O. (1990) The Ants. Belnap Press, Cambridge. https://doi.org/10.1007/978-3-662-10306-7
[2]
Van Zee, J.W., Whitford, W.G. and Smith, W.E. (1997) Mutual Exclusion by Dolichoderine Ants on a Rich Food Source. The Southwestern Naturalist, 42, 229-231.
[3]
Holldobler, B. (1982) Interference Strategy of Iridomyrmex pruinosum (Hymenoptera: Formicidae) during Foraging. Oecologia, 52, 208-213. https://doi.org/10.1007/BF00363838
[4]
Whitford, W.G. (1997) Desertification and Animal Biodiversity in the Desert Grasslands of North America. Journal of Arid Environments, 37, 709-720. https://doi.org/10.1006/jare.1997.0313
[5]
Mackay, W. and Mackay, E. (2002) The Ants of New Mexico (Hymenoptera: Formicidae) Lewiston. Edwin Mellen Press, New York, 400 p.
[6]
Marrs, R.H., Rizand, A. and Harrison, A.F. (1989) The Effects of Removing Sheep Grazing on Soil Chemistry Above-Ground Nutrient Distribution, and Selected Aspects of Soil Fertility in Long-Term Experiments at Moore House National Nature Reserve. Journal of Applied Ecology, 26, 647-661. https://doi.org/10.2307/2404089
[7]
National Research Council (1994) Rangeland Health: New Methods to Classify, Inventory, and Monitor Rangelands. National Academy Press, Washington DC.
[8]
Nash, M.S., Bradford, D.F., Franson, S.E., Neale, A.C., Whitford, W.G. and Heggem, D.T. (2004) Livestock Grazing Effects on Ant Communities in the Eastern Mojave Desert, USA. Ecological Indicators, 4, 199-213. https://doi.org/10.1016/j.ecolind.2004.03.004
[9]
DeBano, S.J. (2006) Effects of Livestock Grazing on Aboveground Insect Communities in Semi-Arid Grasslands of Southeastern Arizona. Biodiversity and Conservation, 15, 2547-2564. https://doi.org/10.1007/s10531-005-2786-9
[10]
Miller, R.H. and Onsager, J.H. (1991) Grasshopper (Orthoptera: Acrididae) and Plant Relationships under Different Grazing Intensities. Environmental Entomology, 20, 807-814. https://doi.org/10.1093/ee/20.3.807
[11]
Welch, J.L., Redak, R. and Krondratieff, B.C. (1991) Effect of Cattle Grazing on the Density and Species of Grasshoppers (Orthoptera: Acrididae) of the Central Plains Experiment Range, Colorado: A Reassessment of Two Decades. Journal of the Kansas Entomological Society, 64, 337-343.
[12]
Whitford, W.G. and Kay, F.R. (1999) Bioperturbation by Mammals in Deserts: A Review. Journal of Arid Environments, 41, 203-230. https://doi.org/10.1006/jare.1998.0482
[13]
Nash, M.S., Whitford, W.G., Van Zee, J. and Havstad, K.M. (2000) Ant (Hymenoptera: Formicidae) Responses to Environmental Stressors in the Northern Chihuahuan Desert. Environmental Entomology, 29, 200-206. https://doi.org/10.1093/ee/29.2.200
[14]
Nash, M.S., Whitford, W.G., Bradford, D.F., Franson, S.E., Neale, A.C. and Heggem, D.T. (2001) Ant Communities and Livestock Grazing in the Great Basin, U.S.A. Journal of Arid Environments, 49, 695-710. https://doi.org/10.1006/jare.2001.0824
[15]
Lightfoot, D.C. and Whitford, W.G. (1989) Interplant Variation in Creosotebush Foliage Characteristics and Canopy Arthropods. Oecologia, 81, 166-175. https://doi.org/10.1007/BF00379801
[16]
Lightfoot, D.C. and Whitford, W.G. (1987) Variation in Numbers of Insects in Desert Shrubs: Is Nitrogen a Factor? Ecology, 68, 547-557. https://doi.org/10.2307/1938460
[17]
Neary, D.G., Ryan, K.C. and DeBano, L.F. (2005) Wildland Fire in Ecosystems: Effect of Fire on Soils and Water. General Technical Report RMRS-GTR-42 Volume 4, U.S. Department of Agriculture Forest Service, Rocky Mountain Research Station, Ogden, 53-71. https://doi.org/10.2737/RMRS-GTR-42-V4
[18]
Havstad, M.K., Juenneke, L.F. and Schlesinger, W.H. (2006) Structure and Function of a Chihuahuan Desert Ecosystem: The Jornada Basin Long-Term Ecological Research Site. LTER Pub. Oxford University Press, Oxford, 465. https://doi.org/10.1093/oso/9780195117769.001.0001
[19]
Nash, M.S., Jackson, E. and Whitford, W.G. (2003) Soil Microtopography on Grazing Gradients in Chihuahuan Desert Grasslands. Journal of Arid Environments, 55, 181-192. https://doi.org/10.1016/S0140-1963(02)00251-3
[20]
Monger, C., Sala, O.E., Duniway, M.C., Goldfus, H., Meir, I.A., Poch, R.M., Throop, H.L. and Vivoni, E.R. (2015) Legacy Effects in Linked Ecological-Soil-Geomorphic Systems of Drylands. Frontiers in Ecology and the Environment, 11, 13-19. https://doi.org/10.1890/140269
[21]
Sala, O.E., Gherardi, L.A., Reichmann, L., Jobbagy, E. and Peters, D. (2012) Legacies of Precipitation Fluctuations on Primary Production: Theory and Data Synthesis. Philosophical Transactions of the Royal Society B, 367, 3135-3144. https://doi.org/10.1098/rstb.2011.0347
[22]
Coppock, D.L., Detling, J.K., Ellis, J.E. and Dyer, M.I. (1983) Plant-Herbivore Interactions in a North American Mixed-Grass Prairie. I. Effects of Black-Tailed Prairie Dogs on Intraseasonal Above-Ground Plant Biomass and Nutrient Dynamics and Plant Species Diversity. Oecologia, 56, 1-9. https://doi.org/10.1007/BF00378210
[23]
Belsky, A.J. (1986) Does Herbivory Benefit Plants? A Review of the Evidence. The American Naturalist, 127, 870-892. https://doi.org/10.1086/284531
[24]
Forbes, G.S., Van Zee, J.W., Smith, W. and Whitford, W.G. (2005) Desert Grassland Canopy Arthropod Species Richness: Temporal Patterns and Effects of Short-Duration Livestock Grazing. Journal of Arid Environments, 60, 627-646. https://doi.org/10.1016/j.jaridenv.2004.07.004
[25]
Nash, M.S. and Whitford, W.G. (2001) Ants as Biological Indicators for Monitoring Changes in Arid Environments: Lessons for Monitoring Protected Areas. In: Research and Management Options for Protected Areas, Proceedings of the First International Symposium and Workshop on Arid Zone Environments, Environmental Research and Wildlife Development Agency, Abu Dhabi, 105-121.
