Factors influencing the presence and relative abundance of Didymosphenia geminata : impact on the composition of diatom assemblages over a broad latitudinal gradient in Chilean rivers

Diatom Research, Journal Year: 2025, Volume and Issue: unknown, P. 1 - 16

Published: Jan. 15, 2025

This study explored the abiotic factors influencing Didymosphenia geminata blooms and combined effect of D. on local diatom assemblages in 13 Chilean watersheds across a broad latitudinal range (37°–47° S). To understand multi-scale drivers, we used generalized linear mixed-effects models to assess most influential presence relative abundance. We then effects α- β-diversity using permutational analyses variance, respectively. Three lacked another three had low Seasonally, abundance was significantly higher spring than autumn. found positive correlations between elevation, river order, pH abundance, while water temperature negatively correlated with Diversity indices were influenced by watershed lower extent geminata. significant spatial (i.e. along south–north gradient) temporal seasons) variations assemblages. Moreover, increasing assemblage diversity. In addition, compositions more alike less variable those non-invaded sites. is first attempt drivers lotic ecosystems.

Language: Английский

Nutrient Accessibility Influences Stalk Formation in the Benthic Diatom Achnanthidium minutissimum

Phycology, Journal Year: 2025, Volume and Issue: 5(2), P. 13 - 13

Published: April 1, 2025

Achnanthidium minutissimum is a widely distributed benthic freshwater diatom. The alga can produce stalks that stick the cell to surface and subsequently extracellular capsules developing into biofilms. Extracts of diatom-associated bacterium Dyadobacter sp. 32 have been shown previously induce stalk capsule formation by Here, we studied impact macronutrients on generation induced bacterial extracts with respect frequency lengths, using axenic cultures avoid any additional bacteria nutrient availability. We found nitrate deprivation inhibited division A. within four days, but it did not initially affect production or elongation. Silica limitation instead both Similarly, sulfate was required for formation, which supported energy-dispersive X-ray spectroscopy cells showing sulfur abundant in stalks.

Language: Английский