The ecology of diatoms in peatlands: Communities from Tierra del Fuego peat bogs as a study case

VALERIA CASA; MARIA VICTORIA QUIROGA; BART VAN DE VIJVER; GABRIELA MATALONI

Ecology of diatoms

scrivener publishing wiley

Año: 2024; p. 1 - 24

Peatlands are one of the most widespread wetland types in the world, inhabited by aremarkable diversity of diatom species. The first part of this chapter overviews the maincharacteristics of diatom communities from peatlands on a global scale, the key genera, theirecological aspects, and the adaptations to these particular environments. The second partfocuses on a study case of diatom communities from Tierra del Fuego-Argentina, thesouthernmost extensive peatland area in the world. Two dome-shaped peat bogs werestudied: Rancho Hambre and Valle de Andorra, which host several shallow ponds in aSphagnum magellanicum matrix. In order to survey their diatom assemblages and theirrelationship with the environmental parameters at different scales, diatom communities werecompared to those of peripheral limnetic environments (moats; rivers; beaver dams), withinpeat bog environments (ponds vs. moss matrix), as well as within pond habitats(sediments vs. periphyton). Despite being 50 km apart, both peat bogs showed highly similarspecies compositions. Furthermore, peat bog assemblages were unique and stood up fromtheir surroundings. A high species turnover was observed despite the short distance betweenpeat bogs and their peripheral environments, mainly due to environmental filters imposed bydistinct physical and chemical conditions. The most relevant parameters in this sense werepH, total hardness, total phosphorus and conductivity. Ponds were the most species-richenvironments, while only a few species inhabited the Sphagnum matrix. Within ponds,periphyton on different mosses (Sphagnum magellanicum, Sphagnum fimbriatum, Sanioniauncinata) showed similar species composition and low richness. On the other hand, thebenthos was the richest community, with a high percentage of exclusive species. Wetherefore conclude that the sediment hosts the most representative diatom assemblages ofpeat bogs, and recommend sampling benthos whenever studying diatom biodiversity in theseenvironments.