Three plant communities positioned along a subtle topographic gradient, referred to as upland, intermediate, and lowland positions, characterize the landscape of the Flooding Pampa grasslands of Argentina. Although it is believed that the structure and functioning of the plant communities at each position are in close relationship with their hydric regime, this has never been quantified. More than 800 measurements of soil water content during four years, along with soil water retention curves, and physical and chemical parameters of soils were assessed at each position. Results showed that water availability during the year varied among the positions in accordance with differences in hydrological balance and soil water retention capacity of each of them. Water retention increased in relation to clay and organic matter content from the upland to the lowland position. The upland position, with more soil sand content, registered severe drought events during late spring and summer, without flooding periods in any season. The intermediate and lowland positions, with more soil clay content, remained flooded for several weeks during winter and spring, and they manifested less severe summer droughts than the upland position. Moreover, the lowland position was more hydromorphic than the intermediate one. These spatial and temporal variations of water regime and soil parameters characterizing the upland, intermediate, and lowland positions concur with different plant communities associated with each of them.
Alconada M., Ansin O.E., Lavado R.S., Deregibus V.A., Rubio G., Boem F.H.Gutiérrez (1993): Effect of retention of run-off water and grazing on soil and on vegetation of a temperate humid grassland. Agricultural Water Management, 23, 233-246 https://doi.org/10.1016/0378-3774(93)90031-5
Aragón Roxana, Oesterheld Martín (2008): Linking vegetation heterogeneity and functional attributes of temperate grasslands through remote sensing. Applied Vegetation Science, 11, 117-130 https://doi.org/10.1111/j.1654-109X.2008.tb00210.x
Batista W., León R.J.C. (1992): Association between the plant communities of the center of the Salado River Basin and some soil properties. Ecología Austral, 2: 47–55. (in Spanish)
Berasategui L.A., Barberis L.A. (1982): Soils and plant communities in the Castelli-Pila region, Salado River Depression (Province of Buenos Aires). Revista de la Facultad de Agronomía, 3: 13–25. (in Spanish)
Black Peter E. (2007): Revisiting the Thornthwaite and Mather Water Balance1. JAWRA Journal of the American Water Resources Association, 43, 1604-1605 https://doi.org/10.1111/j.1752-1688.2007.00132.x
Burkart S.E., León R.J.C., Movia C.P. (1990): Phytosociological inventory of an area of the grasslands of the Depresión del Salado (Buenos Aires Province, Argentina) spanning the main environmental gradients. Darwiniana, 30: 27–69. (in Spanish)
Casanova M.T., Brock M.A. (2000): How do depth, duration and frequency of flooding influence the establishment of wetland plant communities? Plant Ecology, 147: 237–250.
Chapin F.S., Matson P.A., Mooney H.A. (2002): Chapter 7 – Terrestrial decomposition. In: Principle of Terrestrial Ecosystems Ecology. New York, Springer: 151–175.
V. Conzonno, P. Miretzky, Cirelli A. Fernández (2001): The impact of man-made hydrology on the lower stream bed of the Salado River drainage basin (Argentina). Environmental Geology, 40, 968-972 https://doi.org/10.1007/s002540100264
Debelis S.P., Bozzo A.A., Barrios M.B., Buján A. (2005): The relationship between soil characteristics and vegetation as a function of landform position in an area of the Flooding Pampa [Argentina]. Spanish Journal of Agricultural Research, 3, 232- https://doi.org/10.5424/sjar/2005032-143
Deka R.N., Wairiu M., Mtakwa P.W., Mullins C.E., Veenendaal E.M., Townend J. (1995): Use of accuracy of the filter-paper technique for measurenment of soil matric potential. European Journal of Science, 46: 233–238.
DE DEYN G. B., RAAIJMAKERS C. E., VAN DER PUTTEN W. H. (2004): Plant community development is affected by nutrients and soil biota. Journal of Ecology, 92, 824-834 https://doi.org/10.1111/j.0022-0477.2004.00924.x
Di Bella Carla E., Jacobo Elizabeth, Golluscio Rodolfo A., Rodríguez Adriana M. (2014): Effect of cattle grazing on soil salinity and vegetation composition along an elevation gradient in a temperate coastal salt marsh of Samborombón Bay (Argentina). Wetlands Ecology and Management, 22, 1-13 https://doi.org/10.1007/s11273-013-9317-3
FAO (2005): Grasslands of the World. Plant Production and Protection Series No. 34. Roma, FAO.
Fernández-Gálvez J., Barahona E. (2005): Changes in soil water retention due to soil kneading. Agricultural Water Management, 76, 53-61 https://doi.org/10.1016/j.agwat.2005.01.004
Hanks R.J., Ashcroft G.L. (1980): Applied Soil Physics. Berlin, Springer Verlag.
Irisarri J.G.N., Gundel P.E., Clavijo M.P., Durante M., Sosa P. (2013): ANPP and carrying capacity estimation through remote sensing data at the ranch level resolution in the Flooding Pampas. Revista Argentina de Producción Animal, 33: 11–20.
Klute A. (1986): Methods of Soil Analysis. Part 1. 2nd Ed. Madison, Soil Science Society of America.
Knapp A. K., Fahnestock J. T., Hamburg S. P., Statland L. B., Seastedt T. R., Schimel D. S. (1993): Landscape Patterns in Soil-Plant Water Relations and Primary Production in Tallgrass Prairie. Ecology, 74, 549- https://doi.org/10.2307/1939315
Lavado R.S., Taboada M.A. (1988): Water, salt and sodium dynamics in a Natraquoll in Argentina. CATENA, 15, 577-594 https://doi.org/10.1016/0341-8162(88)90008-2
Loreti J., Oesterheld M. (1996): Intraspecific variation in the resistance to flooding and drought in populations of Paspalum dilatatum from different topographic positions. Oecologia, 108, 279-284 https://doi.org/10.1007/BF00334652
MOLLARD FEDERICO P. O., STRIKER GUSTAVO G., PLOSCHUK EDMUNDO L., INSAUSTI PEDRO (2010): Subtle topographical differences along a floodplain promote different plant strategies among Paspalum dilatatum
subspecies and populations. Austral Ecology, 35, 189-196 https://doi.org/10.1111/j.1442-9993.2009.02026.x
Page A.L., Miller R.H., Keeney D.R. (1982): Methods of Soil Analysis. Part 2. 2nd Ed. Madison, Soil Science Society of America.
Paruelo J.M., Sala O.E. (1990): Features of flooding in the Salado depression (Buenos Aires, Argentina): groundwater dynamics. Turrialba, 40: 5–11. (in Spanish)
Perelman S. B., Leon R. J. C., Oesterheld M. (2001): Cross-scale vegetation patterns of Flooding Pampa grasslands. Journal of Ecology, 89, 562-577 https://doi.org/10.1046/j.0022-0477.2001.00579.x
Ratliff L. F., Ritchie J. T., Cassel D. K. (1983): Field-Measured Limits of Soil Water Availability as Related to Laboratory-Measured Properties1. Soil Science Society of America Journal, 47, 770- https://doi.org/10.2136/sssaj1983.03615995004700040032x
RICHARDS L. A. (1949): METHODS OF MEASURING SOIL MOISTURE TENSION. Soil Science, 68, 95- https://doi.org/10.1097/00010694-194907000-00008
Taboada M. A., Lavado R. S. (1993): Influence of cattle trampling on soil porosity under alternate dry and ponded conditions. Soil Use and Management, 9, 139-143 https://doi.org/10.1111/j.1475-2743.1993.tb00943.x