Multiple biomarkers highlight the importance of water column processes in treatment wetland organic matter cycling. (1st January 2020)

• Record Type: Journal Article
• Authors: Morrison, Elise S.; Shields, Michael R.; Bianchi, Thomas S.; Liu, Yina; Newman, Sue; Tolic, Nikola; Chu, Rosalie K.
• Is Part Of: Water research. Volume 168(2020)
• Publication Date: 2020-01-01
• Subjects: Treatment wetlands -- Everglades -- Amino acids -- Pigments -- Lignin -- Biomarkers; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2019.115153
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: A suite of biomarkers, including amino acids, pigments, and lignin phenols coupled with high resolution mass spectrometry were used to evaluate differences in the sources and fate of organic matter (OM) in Everglades treatment wetlands as a model for OM cycling in shallow water wetlands. Five components of the system (water column particulate matter, vertical traps, flocculent material, periphyton, and surface soil) were assessed for OM transformations down-profile (i.e. water column to soil) and between treatment cells dominated by emergent aquatic vegetation (EAV) and submerged aquatic vegetation (SAV), with comparisons to reference sites within the remnant Everglades. We found that OM cycling is fundamentally different between EAV and SAV wetlands, and that SAV wetlands have some shared characteristics with similar habitats in the remnant Everglades. Other than locations densely populated by Typha spp., water column particulate organic C was predominantly derived from microbial/cryptomonad sources, rather than macroscopic sources (vascular plants and algal mats). Bacterial amino acid biomarkers were positively correlated with amino acid degradation indices and organic P (Po ), respectively suggesting that microbial abundance is associated with less degraded OM, and that further investigation into relationships between microbial biomass and Po is warranted. Overall, this multi-biomarker approach can elucidate the relative degradation of OM pools, identify sources of OM, and highlight the importance of water column processes in shallow water wetlands. Graphical abstract: Image 1 Highlights: Biomarker degradation indices tracked organic matter (OM) decay. Biomarkers indicated differences in OM sources between treatment wetland types. Organic matter "freshness" and microbial biomarkers were positively correlated. Amino acids were useful for characterizing OM composition and turnover. Pigments were useful for identifying water column photosynthetic communities.