Related Experiment Video
Updated: Jul 9, 2026

Measuring Phosphorus Release in Laboratory Microcosms for Water Quality Assessment
Published on: July 22, 2019
Spatiotemporal dynamics and release risks of soil phosphorus fractions in the Poyang Lake wetland under
Changlong Guo1, Wenjun Lv1, Luyao Jin1
1State Key Laboratory of Water Resources Engineering and Management, Wuhan University, Wuhan, 430072, China; Hubei Key Laboratory of Water System Science for Sponge City Construction, Wuhan University, Wuhan, 430072, China.
Abstract:
Phosphorus (P) is a fundamental nutrient governing primary productivity, with its mobility and bioavailability primarily dictated by specific fraction. In floodplain wetlands, P fraction dynamics are critical for regulating nutrient cycling and water quality. This study investigated P fractions and release potential along two representative transects (X and T) in the Poyang Lake wetland. Modified sequential extraction and adsorption isotherms were applied to elucidate environmental drivers and ecological risks. The results indicated that: (ⅰ) concentrations of inorganic phosphorus (IP) and bioavailable phosphorus (BAP) in transect X (IP: 35.52-568.94 mg/kg; BAP: 19.18-298.44 mg/kg) were notably higher than those in transect T (IP: 45.45-435.48 mg/kg; BAP: 14.35-184.55 mg/kg); (ⅱ) the relative abundance of P fractions followed the order of occluded phosphorus (Oc-P) > iron bound phosphorus (Fe-P) > aluminum bound phosphorus (Al-P) > detrital calcium-bound phosphorus (De-P) > authigenic calcium-bound phosphorus (Au-P) > exchangeable phosphorus (Ex-P); (ⅲ) soil P generally showed surface accumulation, but its vertical gradient varied spatially and often deviated from a simple linear decline; (ⅳ) soil properties, including nutrients (TC, TN), chemical state (pH), and texture (sand content), were the dominant environmental drivers; and (ⅴ) interannual P evolution was predominantly driven by the frequency of hydrological fluctuations, where drying and wetting frequency remodels soil substrates to drive divergent active phosphorus responses and determine internal release risks in river connected lakes. These findings elucidate the linkages between P fractions and environmental factors in Poyang Lake, providing a scientific basis for wetland conservation and eutrophication mitigation.
Related Concept Videos
The Phosphorus Cycle
Microbial Wastewater Treatment
Soil Microbial Ecology
Responses to Drought and Flooding
Freshwater Microbial Ecology

