Alföldi telepített erdők hatása a felszín alatti sófelhalmozódásra sekély talajvizű területeken | Effect of forest plantations on subsurface salt accumulation in lowlands with shallow groundwater

Az alfoldi uledekes siksagon, szubhumid kliman a fuves teruletek es szantok helyen telepitett erdők erőteljes hatast gyakorolnak a talajtani kozegre, a talajviztukor szintjere es mozgasara. A fak mely gyokerezese es a korabbi vegetacional jelentősen nagyobb vizfelvetele elősegiti a sotartalom-novekedest az altalajban, illetve a talajvizszint-csokkenest. Az erdőtelepites globalis szinten ugrasszerűen megnovekedett, Magyarorszagon az erdők teruletenek novekedese elerte az evi 15.000 ha-os ratat. A telepitesek főleg az Alfoldet erintettek, ahol az erdők reszben sekely talajvizű teruletek gyepeit es szantoit valtottak fel.Kutatasunk soran alfoldszerte 31 erdő-kontroll furatpar eseteben talajtani, hidrologiai es biologiai terepi megfigyeleseket vegeztunk, beleertve a megutott talajvizszint eszlelest, a talajviz sotartalom vizsgalatat, a foldtani kozeg retegződesenek leirasat es a fafaj, valamint az allomany koranak rogziteset. Ezen kivul talajvizszint megfigyelő kuthalozatot telepitettunk es laboratoriumban vizsgaltuk a talaj es talajviz kemiai sajatossagait.A telepitett erdők eseteben a biomassza pozitiv osszefuggest mutatott a talaj sofelhalmozodasanak mertekevel, amit a fafaj (nyar > tolgy > akac) es az allomanykor befolyasolt. A harom vizsgalt fafaj kozott megmutatkozo kulonbsegek a fak elterő novekedesi erelyevel es parologtatasaval mutatnak osszefuggest.Hazankban a teli időszakban megfigyelhető, lefele iranyulo mely csapadekbeszivargas a sok kimosodasat eredmenyezi, igy a sofelhalmozodas merteke kisebb volt a talajban, mint a vizsgalt, hasonlo kornyezeti feltetelekkel, de melegebb klimaval rendelkező argentin pampa teruleteken. | 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 been planted 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 take place and may result in less salt accumulation than in the “Pampas” examined in Argentina, which have similar environmental conditions, but a warmer climate.