Effects of Salinity and Inundation on Microbial Community Structure and Function in a Mangrove Peat Soil
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Shifts in microbial community function and structure can be indicators of environmental stress and ecosystem change in wetland soils. This study evaluated the effects of increased salinity, increased inundation, and their combination, on soil microbial function (enzyme activity) and structure (phospholipid fatty acid (PLFA) signatures and terminal restriction fragment length polymorphisms (T-RFLP) profiles) in a brackish mangrove peat soil using tidal mesocosms (Everglades, Florida, USA). Increased tidal inundation resulted in reduced soil enzyme activity, especially alkaline phosphatase, an increase in the abundance and diversity of prokaryotes, and a decline in number of eukaryotes. The community composition of less abundant bacteria (T-RFLPs comprising 0.3–1 % of total fluorescence) also shifted as a result of increased inundation under ambient salinity. Several key biogeochemical indicators (oxidation-reduction potential, CO2 flux, porewater NH4 +, and dissolved organic carbon) correlated with measured microbial parameters and differed with inundation level. This study indicates microbial function and composition in brackish soil is more strongly impacted by increased inundation than increased salinity. The observed divergence of microbial indicators within a short time span (10-weeks) demonstrates their usefulness as an early warning signal for shifts in coastal wetland ecosystems due to sea level rise stressors.
KeywordsCoastal wetland Peat Sea level rise Salinity Mangrove
We are extremely grateful to the South Florida Water Management District for logistical support and the National Park Service for accommodations and laboratory support at the Florida Bay Interagency Science Center. We also gratefully acknowledge Alan Downey-Wall for his help in conducting this experiment. Partial financial support was provided by National Science Foundation grants DEB- 1237517 and DBI-0620409 and the Everglades Foundation. This is SERC contribution #694 at Florida International University.
- Bell CW, Fricks BE, Rocca JD, et al (2013) High-throughput fluorometric measurement of potential soil extracellular enzyme activities. J Visualized Exp: JoVE e50961. doi: 10.3791/50961
- Berner EK, Berner RA (2012) Global environment: Water, air, and geochemical cycles. Princeton University Press, Princeton, NYGoogle Scholar
- Casamayor EO, Massana R, Benlloch S, et al. (2002) Changes in archaeal, bacterial and eukaryal assemblages along a salinity gradient by comparison of genetic fingerprinting methods in a multipond solar saltern. Environ Microbiol 4:338–348. doi: 10.1046/j.1462-2920.2002.00297.x CrossRefPubMedGoogle Scholar
- Chambers LG, Davis SE, Troxler TG (2015) Sea level rise in the Everglades: plant-soil-microbial feedbacks in response to changing physical conditions. In: Entry JA, Gottlieb AD, Jayachandrahan K, Ogram A (eds) Microbiology of the Everglades ecosystem. CRC Press, Boca Raton, pp. 89–112Google Scholar
- Chrost RJ, Krambeck HJ (1986) Fluorescence correction for measurements of enzyme-activity in natural-waters using methylumbelliferyl substrates. Archiv Fur Hydrobiologie 106:79–90Google Scholar
- Córdova-kreylos AL, Cao Y, Green PG, et al. (2006) Diversity, composition, and geographical distribution of microbial communities in California Salt Marsh Sediments Diversity, composition, and geographical distribution of microbial communities in California Salt Marsh Sediments. Appl Environ Microbiol 72:3357–3366. doi: 10.1128/AEM.72.5.3357 CrossRefPubMedPubMedCentralGoogle Scholar
- Fagherazzi S, Kirwan ML, Mudd SM, et al (2012) Numerical models of salt marsh evolution: ecological, geomorphic, and climate factors. Rev Geophys 50:28. doi: 10.1029/2011rg000359
- Hoppe H-G (1993) Use of fluorogenic model substrates for extracellular enzyme activity (EEA) measurement of bacteria. Handbook of methods in aquatic microbial ecology 423–431Google Scholar
- Neumann JE, Yohe G, Nicholls RJ, Manion M (2000) Sea-level rise & global climate change: a review of impacts to U.S. coasts. 1–43Google Scholar
- Rivera-Monroy VH, de Mutsert K, Twilley RR, et al. (2007) Patterns of nutrient exchange in a riverine mangrove forest in the Shark River Estuary, Florida, USA. Hydrobiologia 17:169–178Google Scholar
- Welch R, Madden M, Doren RF (1999) Mapping the Everglades. Photogramm Eng Remote Sens 65:163–170Google Scholar