Soil carbonand nutrient changes in drained part of efteni wetland

In the current study, organic matter (SO), carbon pool (C), cation exchange capacity (CEC) and macro-nutrient pools of soils were compared among the sites deliberately drained for settlement, agriculture and pasture use over the last 60 years in Efteni-wetland area (EVA) situated in the northwestern Black Sea region of Turkey.In the field, 4 transect with 200 m length and 50 m apart were designated in different directions around the lake situated in the wetland area. Outwards the lake and at the 2nd, 50th, 100rd, 150th and 200rd m on each sampling transect 5 soil profile were dug. From the bottom toward to surface at the 30th, 60th and at the 90th cm of each profile two intact soil samples were collected for physical and chemical analysis.The results revealed that soil bulk density of the first 90 cm depth collected at the farthest point (200 m) from the lake 13 % higher than that of the soil 2 m away from the lake. Soil organic matter (SO) at the 150th and 200rd m were decreased 19 and 30 % respectively compared to the SO at the 50th m. CEC of the soil was moderate along the lake (33 CmolC kg-1). However, this value was declined 50 % at the 200rd m and become poor.There is no interaction between soil depth and the distance of sampling location away from the edge of the lake in terms of the soil C. Data indicate that the first 90 cm of the soil profile 2 m away the lake have about 1.025 % C. However, the corresponding value for the profile at the 150th and 200rd m was decreased 20 and 30 %, respectively.Total N concentration of the soil at the 90 cm depth of the profile located at the 200 m way from the lake was about 0.079 %. The value was 47 % lower than that of the soil at 90 cm depth of the profile located 2 m near to the edge of the lake.In conclusion, soil organic matter, C, CEC and macro-nutrient pools were substantially decreased in the previously drained parts of the wetland. Besides the importance for wildlife and the other ecological functions, the site also important for C sequestration and nutrient cycling. Therefore, landscape should be surveyed and the areas should be delineated for restoration and regain of the previously drained wetland area. And any disturbance to the streams discharge to the wetland and the watershed related to the wetland should be prevented with the legal means.Key words: Efteni, wetland, carbon deposition, nutrient cycling, Düzce