WATER QUALITY ALTERATIONS FROM CANOPY TO SOIL PATHWAY IN FOREST ECOSYSTEMS

This study was aimed to determine the effects of forest ecosystems on water quality alterations. Sample plots 400 m(2) in size were taken in the spruce and fir forest ecosystems distributed in the northeast of Turkey. Water quality parameters such as common exchangeable cations and anions were monthly measured during 20 months period in the precipitation of open area (control), throughfall, stemflow, surface runoff, and filtered water from soil (0-30 cm). Results showed that significant changes occurred in the rainwater from canopy to filtered soil. Finally, in the spruce and fir stands, rainfall water was enriched in terms of anions and cations by touching the plant components such as branches, leaves and stems. In addition, the net precipitation waters coming to the soil surface interacted with inorganic (clay) and organic (humus) particles of the soil. As a result, quality indicators such as pH, K+, Cl-, PO43-, NH4+ decreased while the others parameters like EC, TDS, hardness, Na+, Ca2+, Mg2+, SO42-, NO3- and salinity increased in the filtrated water after soil filtration events. This situation has an important place in better understanding the soil-vegetation-atmosphere interactions.