Resumo

BUENDIA-FLORES, Marisela; TAVERA, Rosaluz  e  NOVELO, Eberto. Floristic and ecology of benthic diatoms in the lake area of Xochimilco-Tláhuac, Mexico. Bot. sci [online]. 2015, vol.93, n.3, pp.531-558. ISSN 2007-4476.  https://doi.org/10.17129/botsci.148.

91 taxa of benthic diatoms were recorded at several sites in the lake district Xochimilco-Tláhuac representing an increase of over 50 % in the floristic inventory of diatoms in this area. The study was based on analysis of 13 collections with fortnightly and monthly sampling during the dry and rainy seasons, simultaneously recording several environmental factors that supported a comparative analysis for changes in species richness between study sites and collections. An ecological categorization of species allowing to associate their presence with the environmental conditions of the lake area, arguing that the dominant species distinguished floristically a region, while frequent distinguish the local flora and rare species indicate habitat fragmentation. The composition and species richness showed a clear relationship with environmental factors and highlighted the presence of Nitzschia frustulum, Pseudostaurosira brevistriata, Fragilaria bidens, Rhoicosphenia abbreviata, Fragilariforma virescens, Staurosira construens, S. construens var. binodis, Staurosirella leptostauron y S. pinnata, which are species typically found in the sediments of shallow and eutrophic bodies of water. Species richness was statistically correlated with the variation of silica and pH, which showed that benthic diatoms can be used as ecological indicators for monitoring environmental conditions in the lake district of Xochimilco-Tláhuac.

Palavras-chave : Bacillariophyta; benthos; ecology; eutrophication; species richness.

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