Primary Producers and Anthropic Signs Related to the Flood Plain Soils of the Tablas de Daimiel Wetland

Abstract

Abstract:In the Tablas de Daimiel National Park (TDNP) wetlands, a semi-arid wetland system in Spain that is of international importance, it is believed that pollutants from a variety of sources accumulate. In the study reported here, we evaluated soils from the flooded part of this wetland in an effort to establish relationships between the abundance/structure of microbial communities (mainly cyanobacteria) and certain soil properties (redox potential, dissolved oxygen, organic matter, soil reaction, electrical conductivity, calcium carbonate, total nitrogen, soluble phosphorus and total phosphorus). This objective was achieved by establishing one transect from the entrance to exit of the flood plain, including sampling from potentially polluted sites. Substantial variations between sampling sites were found in soil in terms of salinity, dissolved oxygen (DO), organic matter (OM), total phosphorus (TP) and nitrogen (TN). The presence of primary producers was more evident in contaminated samples. In addition to calcium, high levels of oxidizable organic matter, traces of dissolved oxygen, and considerable amounts of nitrate and phosphates probably stimulated the growth of cyanobacteria, these latter characteristics can be explained as being due to the influence of wastewaters from urban, industrial and agricultural activities that run off directly into this unique wetland. In the future it will be necessary to understand the synergic effects of other soil properties.

Inundation impacts on diversified pasture biomass allocation and soil particulate organic matter stocks

“…Although the whole soil C and N stocks were not significantly affected by inundation, which can be explained by the slower organic matter decomposition under lower oxygen concentration on inundated soils (Garcia-Navarro et al, 2018), we did observe a reduction in total C concentration in the whole soil (Table S3), which is an indication of potential stock depletion (Franzluebbers & Stuedemann, 2002). Furthermore, soils under inundation can have a lower stabilization of organic matter, as anaerobic conditions can cause Fe reduction, which release C bound to Fe and increases SOM mineralization (Huang et al, 2020;Huang & Hall, 2017).…”

“…Therefore, it is expected that cool‐season mixtures will increase soil C and N stocks in the long‐term due to rapid turnover of roots at shallow layers, and longer residence time at deeper layers (Houde et al, 2020). Although under inundation conditions, positive effects of higher belowground input may take longer to occur due to slower residue decomposition rates (Garcia‐Navarro et al, 2018).…”

Cyanobacterial Blooms: Current Knowledge and New Perspectives

“…Their emergence dates back from 2.8 billion years ago [1]. Inhabitants of a wide range of ecosystems, from the Polar regions to other habitats such as cold and hot deserts, hot springs, and flood plain soils [2][3][4][5], cyanobacteria are microorganisms that possess a global occurrence. As primary producers of aquatic and terrestrial food chains, cyanobacteria currently have increasing biotechnological applications and as a source of new drugs for medical treatment [6].…”