The activities of extracellular enzymes are important in understanding decomposition of soil organic matter in wetlands subjecting to drying. The activity of soil extracellular enzymes (β-glucosidase, N-acetylglucosaminidase, and phosphatase), and related physicochemical parameters were monitored in constructed freshwater wetlands during a one-month drying manipulation. Drying increased redox potential and decreased soil water content significantly (P<0.05). Higher content of soil organic matter (P<0.05) and higher concentrations of inorganic N (nitrate, P<0.01; and ammonia, P<0.001) were also observed significantly under drying condition. Soil hydrolase enzyme activities were stimulated significantly (β-glucosidase, P<0.05; N-acetylglucosaminidase, P<0.01; and phosphatase, P<0.001), and a two-phase pattern of enzyme activities was revealed under drying condition. The increase of soil enzyme activities under drying condition was significantly related to soil redox potential (P<0.001). Drying strongly affected soil enzyme activities only when soil water content remained above an optimal level for enzymatic catalysis (higher than 23% w/w), corresponding to redox potentials below 250-300 mV. Our results suggest that, under drying condition, potential enzyme activities may be regulated by redox potential, in respect to soil moisture, and consequently alter nutrient availability in wetlands.
|Number of pages||20|
|Journal||Chemistry and Ecology|
|Publication status||Published - 2013 Feb|
Bibliographical noteFunding Information:
This study was supported by NRF (2010-0028708; 2011-0030838).
All Science Journal Classification (ASJC) codes
- Ecology, Evolution, Behavior and Systematics
- Environmental Science(all)
- Earth and Planetary Sciences(all)