干旱区生态环境知识资源中心

Wetland pollution and other changes have led to the serious degradation of wetlands worldwide. The Tablas de Daimiel National Park (TDNP) wetland is a unique wetland in a semi-arid region of Mediterranean climate (Central Spain) and it has suffered significant degradation. In an effort to evaluate the magnitude of this degradation, a total of 43 soil sampling stations were selected in the flood plain area of this wetland. Parameters such as pH, electrical conductivity (EC), dissolved oxygen (DO), calcium carbonate and nutrients (N, P, S, C, S) in the soil were measured along with other trace elements (Br and I). The results were analyzed and a significant spatial variability of the parameters was found. The results of the analysis indicate that the TDNP wetland has a significant capacity to retain and sequester carbon. The elements Br and I had the highest anthropogenic proportions in certain soils in the study area; Br was present in the range 7.7-375.7 mg/kg, with an average value of 74.8 mg/kg, whereas I was present in the range 20.0-277.0 mg/kg, with an average value of 39.4 mg/kg. Both of these average values are much higher than the reference levels in the region. N and P were also present and in some cases these also had higher values than the reference. Wastewaters from urban/industrial activities and from agricultural runoff are the cause of these anomalous levels released into this unique wetland and these concentrations may be harmful to living organisms.