Effect of forest plantations on subsurface salt accumulation in lowlands with shallow groundwater

BALOG, K; GRIBOVSZKI, Z; SZABÓ, A; JOBBÁGY, E G; NOSETTO, M D; KUTI, L; PÁSZTOR, L; TÓTH, T

Agrokémia és Talajtan (Agrochemistry and Soil Science)

Akadémiai Kiadó

Año: 2014 vol. 63 p. 249 - 268

0002-1873

The forests that have replaced grasslands and croplands on the sedimentary plain of the Great Hungarian Plain, in a sub-humid climate, have a strong impact not only on the soil, but also on the level and movement of the groundwater table. Subsurface salt accumulation and groundwater depletion are facilitated by the significantly greater water uptake of deep-rooted trees. Forest cover has significantly increased worldwide. In Hungary, the increase in newly forested areas has reached an annual rate of 15,000 hectares. The majority of forests have beenplanted on lowlands with a shallow water table. A detailed pedological, hydrological and biological field survey was carried out on 31 pairs of forest and control stands. The investigation focused on water table depth and salinity, subsoil layering, tree species and stand age. In addition, a well network was installed to observe the groundwater level.Chemical characteristics of the soil and groundwater were analyzed in the laboratory. Total tree biomass was positively correlated with the rate of subsoil salt accumulation in the plantations, which was influenced by the tree species (Poplar > Common oak > Black Locust) and stand age. The mechanism behind the differences between the three tree species seems to be based on differences in growth vigour and evapotranspiration. Due to the seasonal reversal in the direction of groundwater movement in Hungary, the conditions allow regular leaching to takeplace and may result in less salt accumulation than in the Pampas examined in Argentina, which have similar environmental conditions, but a warmer climate.