Environmental factors controlling lake diatom communities: a meta-analysis of published data

Abstract

Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Printer-friendly Version Interactive Discussion Abstract Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Printer-friendly Version Interactive Discussion AbstractDiatoms play a key role in the development of quantitative methods for environmental reconstruction in lake ecosystems. Diatom-based calibration datasets developed during the last decades allow the inference of past limnological variables such as TP, pH or conductivity and provide information on the autecology and distribution of diatom 5 taxa. However, little is known about the relationships between diatoms and climatic or geographic factors. The response of surface sediment diatom assemblages to abiotic factors is usually examined using canonical correspondence analysis (CCA) and subsequent forward selection of variables based on Monte Carlo permutation tests that show the set of predictors best explaining the distributions of diatom species. The 10 results reported in 40 previous studies using this methodology in different regions of the world are re-analyzed in this paper. Bi-and multivariate statistics (canonical correlation and two-block partial least-squares) were used to explore the correspondence between physical, chemical and physiographical factors and the variables that explain most of the variance in the diatom datasets. Results show that diatom communities 15 respond mainly to chemical variables (pH, nutrients) with lake depth being the most important physiographical factor. However, the relative importance of certain parameters varied along latitudinal and trophic gradients. Canonical analyses demonstrated a strong concordance with regard to the predictor variables and the amount of variance they captured, suggesting that, on a broad scale, lake diatoms give a robust indication 20 of past and present environmental conditions.( Chen et al., 2008; Edulnd and Ramstak, 2006). Diatom-based predictive models, us-15890 BGD

Terrestrial diatoms as tracers in catchment hydrology: a review

“…Diatom literature 50,51 stresses the importance of ion concentration and trophic status as major environmental drivers of diatom distributions in lakes and streams, 52 while physical factors typically have a lesser effect on community structure. Moreover, studies where spatial configuration accounted for a significant proportion of the community variance clearly outnumbered the studies suggesting strict local environmental control.…”

A high-resolution paleolimnological study of climate and human impacts on Lac Noir, Québec, over the past 1000 yr

“…A comparison of the paleorecords from Lac Brûlé and Lac Noir (25 km apart) showed that the vegetation surrounding each of the two sites responded to environmental changes similarly in timing and direction of change, with some exceptions (Lafontaine-Boyer and Gajewski, 2014). Diatom community composition was more unique to each lake as a result of local catchment-scale characteristics, including basin morphometry, habitat availability, water chemistry, and disturbances (Blanco, 2014). Regardless, most of the pollen taxa and several of the abundant diatom species were common to both sites and were directly comparable (Fig.…”

Diatom species composition in the Raska river (Southwestern Serbia)

“…They are distributed throughout the world in nearly all types of aquatic systems and are one of the most important food resources in marine and freshwater ecosystems [Wichard et al, 2007;Medlin 2011]. A key issue in understanding diatom distribution is knowing the extent to which they are constrained by geographical factors that limit species dispersal vs. the extent to which they are limited only by the ability of the species to grow under a specific combination of environmental factors [Blanco 2014]. Ability of populations to compete and persist in a new local habitat depends on how well adapted they are to grow under its environmental conditions.…”