Abstract: Aimed to understand the effects of different cover condition on the main nutrients contents in wetland soil, three kinds of wetland plots in Shuangtaizi estuarine, i.e., land with living vegetation (PA), land with dead vegetation (PD), and bare beach (GT), were selected, and a total of 21 soil samples were collected, with their total nitrogen (TN), phosphorus (TP), and potassium (TK) contents determined. In the plots GT, PD, and PA, the soil TN content was averagely 0.79, 1.01, and 1.29 g·kg^-1, soil TP content was averagely 0.49, 0.50, and 0.52 g·kg^-1, and soil TK content was averagely 22.29, 23.01, and 23.40 g·kg^-1, respectively. Soil TN content differed significantly with cover condition (P<0.05), but soil TP and TK contents had no significant differences among the three plots (P>0.05;P>0.05), indicating that vegetation could increase soil TN content effectively, but had little influence on soil TP and TK contents. In vertical direction, soil TN and TP contents showed similar distribution pattern, i.e., PA>PD>GT, while soil TK was in the order of PA>GT>PD. With the increase of soil depth, soil TN content decreased after an initial increase, soil TP content changed little at 0-30 cm but increased below 30 cm, with a significant increase in PA, while soil TK content changed greatly from the surface to deep layer. In the degrading process of PA-PD-GT, soil TN, TP, and TK contents decreased by 38.6%, 6.9%, and 4.7%, respectively.

Key words: Quercus variabilis, Age structures, Distribution pattern, Life tables, Survival curve