Simultaneously, macrophytes adaptations to anoxia as radial O 2 loss (ROL) from roots stimulate the growth of aerobic bacteria in sediments and the development of unique microbiome adjacent to roots, oxidize the rhizosphere, and favor phosphorus (P) retention and nitrogen (N) removal (Racchetti et al. The latter increases the organic content of sediments, stimulating anaerobic metabolism (Soana et al. Macrophytes increase habitat complexity, have a structuring role, and support an array of biogeochemical services in aquatic ecosystems as O 2 production, nutrient uptake, and particulate matter retention (Sand-Jensen 1998). The increase of pelagic primary production and sedimentation rates has resulted in large inputs of labile organic matter (OM) to surface sediments with a positive feedback for nutrient regeneration and a negative feedback for macrophytes recovery (Hilt et al. simplified (microbial-dominated) benthic communities.Įutrophication in inland waters has resulted in widespread loss of biodiversity, including dramatic reduction of rooted macrophytes and associated macrofauna (Egertson et al. Such experiments demonstrate a large decrease in methane emission and nutrient loss/retention in biodiverse (macrophytes and macrofauna colonized) vs. With manipulative laboratory experiments reproducing a gradient from bare sediments to sediments colonized by macrophytes and macrofauna, we provide evidence of important biogeochemical services offered by vegetation and associated invertebrates in organic sediments. However, current canals management minimizes hydraulic resistance via mechanical removal of vegetation, which affects their potential to reduce greenhouse gas emissions and improve biological habitat and water quality. The same canal networks represent an opportunity for restoration of lowland ecosystems due to the large area that canals cover nowadays. Results suggest that the maintenance of vegetation and associated macrofauna in organic sediments promotes their combined ecosystem services, resulting in significant reduction of greenhouse gas emission and nutrient release to the water column.Īrtificial drainage and irrigation canals have converted floodplains into productive agricultural areas, resulting in extensive loss of biodiversity and ecosystem services. Oligochaetes increased N 2 production by ~ 200 mmol N m −2 and nitrate consumption by a factor of 4, whereas macrophytes reduced nitrogen losses by ~ 65 mmol N m −2. Along a 12-d experiment, CH 4 ebullition in bare sediment (470 ± 13 mmol m −2) decreased by 67%, 88%, and 97% in the presence of plants, oligochaetes, and both organisms, respectively. We tested this hypothesis via incubations of microcosms reproducing four treatments: bare sediment, sediment with oligochaetes, sediment with macrophytes, and sediment with both organisms. They may display lower methane (CH 4) emissions and increase nutrient retention when macrophytes and macrofauna are present, due to oxygen leakage from roots and bioirrigation. In reality we are the perfect ambassadors of the ocean.Organic sediments are greenhouse gas and nutrient hotspots. We are the guinea pigs of society when it comes to the what's going on in the oceans, we surfers, we live on the ocean, we literally submerge ourselves, we have ocean water into our ears, eyes and skin. The sea level rise from Western Antarctica will eventually submerge Hamburg, Shanghai, New York and Hong Kong, you can't negotiate with physics: that's the dilemma here. This certainly does not mean that the current of pessimism is eventually to submerge the other, but it proves that it does not lose ground and that it does not seem destined to disappear. It is a quite remarkable fact that the great religions of the most civilized peoples are more deeply fraught with sadness than the simpler beliefs of earlier societies. You would not want to submerge your head, nothing but fish going "Ahhh, fuck! I thought I looked like that rock! If fish could scream, the ocean would be loud as shit.
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