Sedimentary Enzyme Kinetics of Land/Water Ecotones with Reed Domination

Abstract

Land/water ecotones, the transitional boundary zone between terrestrial and aquatic ecosystems, can effectively trap and assimilate nutrients from external sources. The changes of nutrient cycling will cause a response in enzyme activity. In this paper, the enzyme kinetics of land/water ecotones in a shallow eutrophic wetland in China, dominated by a reed (Phragmites australis) community, are studied. The results indicate that land/water ecotones exhibit a strong filtration function and nutrient factor is an important feature affecting the distribution of enzymes in the transect of the littoral zone. The obvious spatial differences of enzyme activities and nutrients are present in the transect of the reed beds. The land area is the hot zone, where significant changes in enzyme activity occur. T-test results show that the landward spot, 1 m away from the water-land interface, is quite different from other spots, and the 1 m spot is the hot spot where great biochemical change happens. The principal component analysis of the environmental variables shows that nutrient factors have an important affect on enzyme distribution in the transect of the littoral zone. The nutrient factor explains about 54% of the observed variance. In particular, TOC (total organic carbon) correlates with the other five factors (TN; total nitrogen, TP; total phosphorus, phosphatase, b-glucosidase, and urease) with correlative coefficients of 0.932, 0.595, 0.488, 0.433, and -0.468, respectively. The results indicate that TOC is a very important factor in Baiyangdian wetlands.

Effect of straw and polyacrylamide on the stability of land/water ecotone soil and the field implementation

“…Hence, soil nutrients are important factors that directly affect soil stability (Risser, 1990). According to a previous report (Austin, 2006;Edwards and Bremner, 2006;Wang et al, 2010), aggregate and physical stability are important factors in L/WE soil fertility and stability. Resistance of the aggregate to physical stresses determines soil sensitivity to crusting and erosion , germination and rooting of cultivated plants (Frank and Martin, 2013), and the ability of a soil to absorb nutrients (Li et al, 2009).…”