Regional patterns and controls of ecosystem salinization with grassland afforestation along a rainfall gradient

Vegetation change affects water fluxes and influences the direction and intensity of salt exchange between ecosystems and groundwater. In some conditions it can also lead to an intense accumulation of salts in soils and aquifers, as has been documented for the conversion of native grassland to tree plantations in the plains of Argentina, Hungary and Russia. In this paper we present a hierarchical framework to predict salt accumulation following vegetation change that is based on climatic, hydrogeological and biological factors. We evaluated this spatially explicit framework in temperate South America using a network of 32 pairs of adjacent plantation and grassland stands studied with detailed field measurements and remotely sensed imagery from MODIS. Our sites cover a broad precipitation gradient (770 to 1500 mm a−1) and are underlain by shallow water tables (<2.5 m of depth). At the regional scale, geoelectric surveying revealed that the salinization of plantation soils depended strongly on climate, occurring only where the annual water balance (mean precipitation‐Penman‐Monteith potential evapotranspiration) was <100 mm a−1 (p < 0.0001, n = 24). At the local scale, we observed that groundwater salinities observed under ∼50‐year old plantations of different species were associated with their tolerance to salinity (p < 0.001, n = 10). Salinization occurred rapidly where rainfall was insufficient to meet the water requirements of tree plantations and where groundwater use compensated for this deficit, driving salt accumulating in the ecosystem. A general understanding of the vegetation‐groundwater relationship will help predict and manage the negative and positive consequences of groundwater use from stand to regional levels of analysis.

[1]  Esteban G. Jobbágy,et al.  Forestación en pastizales: hacia una visión integral de sus oportunidades y costos ecológicos , 2006, Agrociencia.

[2]  Lu Zhang,et al.  Response of mean annual evapotranspiration to vegetation changes at catchment scale , 2001 .

[3]  J. Morris,et al.  Water use and salt accumulation by Eucalyptus camaldulensis and Casuarina cunninghamiana on a site with shallow saline groundwater , 1999 .

[4]  D. Spennemann.  Urban and heritage landscapes . Under the saline threat . The potential impact of salinity on cultural and natural values of urban landscapes , 2003 .

[5]  Laurent Durieux,et al.  The impact of deforestation on cloud cover over the Amazon arc of deforestation , 2003 .

[6]  J. Wright,et al.  Latin American Forest Plantations: Opportunities for Carbon Sequestration, Economic Development, and Financial Returns , 2000 .

[7]  P. Domenico,et al.  Physical and chemical hydrogeology , 1990 .

[8]  M. Nosetto,et al.  The effects of tree establishment on water and salt dynamics in naturally salt-affected grasslands , 2007, Oecologia.

[9]  D. Keeney,et al.  Soil nitrogen mineralization as affected by water and temperature interactions , 1987, Biology and Fertility of Soils.

[10]  D. L. Carter,et al.  Saline and Sodic Soils , 1982, Advanced Series in Agricultural Sciences.

[11]  R. Coupland,et al.  Natural grasslands : introduction and Western Hemisphere , 1992 .

[12]  A. Soriano.  Rio de la Plata grasslands , 1992 .

[13]  W. Berry,et al.  LOCALIZATION AND SECRETION OF SALT BY THE SALT GLANDS OF Tamarix aphylla. , 1969, Proceedings of the National Academy of Sciences of the United States of America.

[14]  H. Akaike.  A new look at the statistical model identification , 1974 .

[15]  M. G. Ryan,et al.  The effect of fertilization on sap flux and canopy conductance in a Eucalyptus saligna experimental forest , 2004 .

[16]  C. Justice,et al.  Atmospheric correction of MODIS data in the visible to middle infrared: first results , 2002 .

[17]  R. B. Jackson,et al.  Groundwater use and salinization with grassland afforestation , 2004 .

[18]  C. Justice,et al.  Development of vegetation and soil indices for MODIS-EOS , 1994 .

[19]  G. Walker,et al.  Uptake of saline groundwater by plants: An analytical model for semi-arid and arid areas , 1995, Plant and Soil.

[20]  R. George,et al.  Interactions between trees and groundwaters in recharge and discharge areas - A survey of Western Australian sites , 1999 .

[21]  Bruce A. McCarl,et al.  Trading Water for Carbon with Biological Carbon Sequestration , 2005, Science.

[22]  R. B. Jackson,et al.  Groundwater and soil chemical changes under phreatophytic tree plantations , 2007 .

[23]  松井 健.  FAO (1991) World Soil Resources. An explanatory note on the FAO World Soil Resources Map at 1 : 25,000,000 Scale , 1992 .

[24]  J. Paruelo,et al.  Potential long‐term impacts of livestock introduction on carbon and nitrogen cycling in grasslands of Southern South America , 2006 .

[25]  I. Calder.  Water use by forests, limits and controls. , 1998, Tree physiology.

[26]  G. Bouyoucos.  Hydrometer Method Improved for Making Particle Size Analyses of Soils1 , 1962 .

[27]  R. B. Jackson,et al.  Hydrological consequences of Eucalyptus afforestation in the Argentine Pampas , 2005 .

[28]  Jerry Brown,et al.  Studies of Salt Tolerance of Landscape Plant Species and California Native Grasses for Recycled Water Irrigation , 2001 .

[29]  T. Edwards.  Trees, water and salt. An Australian guide to using trees for healthy catchments and productive farms , 2003 .

[30]  J. Monteith.  Does transpiration limit the growth of vegetation or vice versa , 1988 .

[31]  Andreas Richter,et al.  Salt tolerance in Eucalyptus spp.: identity and response of putative osmolytes , 2005 .

[32]  T. Geary.  Afforestation in Uruguay: Study of a Changing Landscape , 2001 .

[33]  Mike Kirkby,et al.  Causal processes of soil salinization in Tunisia, Spain and Hungary , 2001 .

[34]  R. B. Jackson,et al.  Patterns and mechanisms of soil acidification in the conversion of grasslands to forests , 2003 .

[35]  A. Heuperman.  Hydraulic gradient reversal by trees in shallow water table areas and repercussions for the sustainability of tree-growing systems , 1999 .

[36]  Richard George,et al.  Salinity Threatens the Viability of Agriculture and Ecosystems in Western Australia , 1997 .

[37]  J. McComb,et al.  Salt tolerance screening of selected Australian woody species — a review , 2000 .

[38]  K. Tanji,et al.  Agricultural Drainage Water Management in Arid and Semi-Arid Areas , 2002 .

[39]  José M. Paruelo,et al.  Land‐use change and water losses: the case of grassland afforestation across a soil textural gradient in central Argentina , 2005 .

[40]  D. Adriano,et al.  Bromine, Chlorine, and Fluorine , 2015 .

[41]  A. Huete,et al.  Overview of the radiometric and biophysical performance of the MODIS vegetation indices , 2002 .

[42]  S. Running,et al.  Ecohydrological changes in the Murray-Darling Basin. III: A simulation of regional hydrological changes , 1993 .

[43]  Ana Moliner,et al.  Use of pruning waste compost as a component in soilless growing media. , 2005, Bioresource technology.

[44]  N. Schofield.  Tree planting for dryland salinity control in Australia , 1992, Agroforestry Systems.

[45]  W. Bond,et al.  Growth and water use of Eucalyptus grandis and Pinus radiata plantations irrigated with effluent. , 1996, Tree physiology.

[46]  M. Hulme,et al.  A high-resolution data set of surface climate over global land areas , 2002 .

[47]  D. Hollinger,et al.  MODELING GROSS PRIMARY PRODUCTION OF AN EVERGREEN NEEDLELEAF FOREST USING MODIS AND CLIMATE DATA , 2005 .

[48]  N. Kitchen,et al.  Accuracy issues in electromagnetic induction sensing of soil electrical conductivity for precision agriculture , 2001 .

[49]  Kálmán Rajkai,et al.  SOIL AND PLANT CORRELATIONS IN A SOLONETZIC GRASSLAND , 1994 .

[50]  M. Sapanov.  Water uptake by trees on different soils in the Northern Caspian region. , 2000 .

[51]  N. I. Bazilevich,et al.  The geochemistry of soda soils , 1970 .

[52]  R. B. Jackson,et al.  Vegetation–Climate Feedbacks in the Conversion of Tropical Savanna to Grassland , 2000 .

[53]  J. Shukla,et al.  Amazon Deforestation and Climate Change , 1990, Science.

[54]  Jiří Koryta.  ION-Selective Electrodes , 1986 .

[55]  J. Tricart.  Geomorfología de la Pampa Deprimida : base para los estudios edafológicos y agronómicos , 1973 .

[56]  H. A. Mooney,et al.  Maximum rooting depth of vegetation types at the global scale , 1996, Oecologia.

[57]  E. Barrett-Lennard.  Restoration of saline land through revegetation , 2002 .

[58]  Robert B. Jackson,et al.  Effects of afforestation on water yield: a global synthesis with implications for policy , 2005 .