title: High temperature and salinity enhance soil nitrogen mineralization in a tidal freshwater marsh.
abstract: Soil nitrogen (N) mineralization in wetlands is sensitive to various environmental factors. To compare the effects of salinity and temperature on N mineralization, wetland soils from a tidal freshwater marsh locating in the Yellow River Delta was incubated over a 48-d anaerobic incubation period under four salinity concentrations (0, 10, 20 and 35‰) and four temperature levels (10, 20, 30 and 40°C). The results suggested that accumulated ammonium nitrogen (NH4+-N) increased with increasing incubation time under all salinity concentrations. Higher temperatures and salinities significantly enhanced soil N mineralization except for a short-term (≈10 days) inhibiting effect found under 35‰ salinity. The incubation time, temperature, salinity and their interactions exhibited significant effects on N mineralization (P<0.001) except the interactive effect of salinity and temperature (P>0.05), while temperature exhibited the greatest effect (P<0.001). Meanwhile, N mineralization processes were simulated using both an effective accumulated temperature model and a one-pool model. Both models fit well with the simulation of soil N mineralization process in the coastal freshwater wetlands under a range of 30 to 40°C (R2 = 0.88-0.99, P<0.01). Our results indicated that an enhanced NH4+-N release with increasing temperature and salinity deriving from the projected global warming could have profound effects on nutrient cycling in coastal wetland ecosystems.
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, China.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, China.
authors.forename: Junhong
authors.initials: J
authors.lastname: Bai
authors.affiliation: NSW Department of Primary Industries, West Pennant Hills, New South Wales, Australia.
authors.forename: Xinhua
authors.initials: X
authors.lastname: He
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, China.
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, China.
authors.forename: Qiongqiong
authors.initials: Q
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, China.
authors.forename: Junjing
authors.initials: J
authors.lastname: Wang
mesh_terms: D064751:Ammonium Compounds / Q000032:analysis; D000704:Analysis of Variance; D002681:China; D005618:Fresh Water; D008903:Minerals / Q000737:chemistry*; D008962:Models, Theoretical; D009584:Nitrogen / Q000737:chemistry*; D054712:Salinity; D012987:Soil / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors; D014872:Water Movements; D053833:Wetlands
chemical_list: D064751:Ammonium Compounds; D008903:Minerals; D012987:Soil; D009584:Nitrogen
references.citation: Environ Manage. 2005 Jan;35(1):72-83
references.pmid: 15984065
references.citation: PLoS One. 2011;6(11):e27645
references.pmid: 22096609