The Vegetal Benthos

overall, 35 taxa of cyanobacteria, 28 taxa of clorophyta and 61 taxa of Diatoms (77 taxa in stream sites) were identified. Species richness of the remaining algal groups is low and encompasses planktic-living taxa. Spatial distribution of algal groups and cyanobacteria depended mostly on water temperature and flow velocity. Similarities among lake and stream cyanobacteria and algae are pretty low (R-2 < 40%). In streams, assemblages do not cluster by altitude or substrate type. In the lake, the periphytic assemblages are not clustered by life mode of host (submerged vs emergent), evolutionary group (angiosperms vs charophytes), or the occurrence of carbonate deposits. Diatom dominance changes along with plant substrate, Cymbella microcephala being the most frequently dominating species in the lake. Beta diversity of benthic algae happens to be higher in stream environments, and that of diatoms is higher than that of overall algae and cyanobacteria jointly. Mosses were only frequent upstream the lake, particularly at the Manadero spring.Vascular hydrophyte taxa was 9 (3 characean and 6 angiosperms), whereas those of helophytes and hygrophytes were 13. Chara hispida attains higher biomass than C. vulgaris, and this is located at deeper depths than the former, but it does not grow every year. Groenlandia densa (always in areas shallower than 2 m) reached high biomass but the cover of Sparganium emersum was much higher, occurring throughout the lake perimeter close to Cladium mariscus. Ranunculus trichophyllus depicts a very small cover at the northeast basin. Regarding emergent vegetation, shores are almost entirely surrounded by a cutsedge fringe (Cladium mariscus) and reed (Phragmites australis) and, in flooded southeastern areas, the wide-leaf cattail (Typha latifolia) grows. Carex riparia can be found at the north shore and C. paniculata occurs at east.The lowest carbon content was found in Groenlandia, whereas Sparganium shown the highest nitrogen. Phosphoras concentration in stoneworts was at the lower extreme of what is reported in the literature. Cladium contained less N and P, but higher C, whereas Phragmites harbours more N and Carex acutiformis more P. The lowest N:P ratio is found in Carex riparia, with Cladium exhibiting the highest P limitation. Among the four studied submerged macrophytes, angiosperms produce and respire a lot more than Chara spp; with Groenlandia densa being the highest net producer. As a whole, production per unit of DW biomass of Somolinos submerged plants can exceed the ranges measured by other authors. Groenlandia again showed the highest production and respiration rates, (376-1.227 mg C/m(2) h y 509-857 mg O-2/m(2) h, respectively). Reed net photosynthesis was the highest and more variable of all three emergent species tested, followed by that of greater pond sedge (Carex riparia).