作者: B Gribsholt , E Kristensen
DOI: 10.3354/MEPS241071
关键词:
摘要: The impact of benthic macrofauna (Nereis diversicolor) and macrophytes (Spartina anglica) on the dynamics microbial mineralization rates pathways in saltmarsh sediment was studied over 1 growing season. Measurements were conducted 4 mesocosms subjected to a natural tidal regime, inhabited by either flora, fauna or both, kept without presence macroorganisms. Total measured during spring, summer fall as sed- iment oxygen uptake carbon dioxide release under air-exposed well inundated conditions, while anaerobic quantified sulfate reduction. Porewater concentration profiles total (TCO2), dissolved organic (DOC), SO4 2- , Cl - Fe 2+ determined monthly. had minor effects plant growth, vegetated S. anglica renders habitat unsuitable for N. diversicolor, possibly due food limitation. Without macroorganisms, dense algal mat (Vaucheria sp.) developed surface. As result, greatly reduced with respiration completely dominated sul- fate Grazing (N. surface free epibenthic microalgae, irrigation oxidized top 15 20 cm enhancing porewater exchange overlying water. TCO2, DOC only accumulated below depth. Sulfate reduction still dominating degradation pathway, accounting 50 60% mineralization. flora (S. enhanced miner- alization but lowered importance (22 54%). constituents such TCO2 low relatively evenly distributed oxidizing capacity evident throughout column. both pro- duced largest increase oxic rates. In conclusion, mesocosm approach simulated salt marsh conditions well, results provide good evi- dence interactions between their geochemistry.