Environmental and overgrazing effects on diatom communities in high mountain mires

High mountain mires are affected by anthropogenic activities such as livestock, which have changed land use, fragmented habitats, and affected the structure and functioning of aquatic communities such as diatoms. Diatoms in mires exhibit high diversity, with a significant proportion of rare and thre...

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Detalles Bibliográficos
Autores: Gonzalez-Saldias, Fernanda, Pérez Haase, Aaron, Pladevall Izard, Eulàlia, Gomà Martínez, Joan
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/223154
Acceso en línea:https://hdl.handle.net/2445/223154
http://hdl.handle.net/2445/223154
Access Level:acceso abierto
Palabra clave:Diatomees
Zones humides
Pirineus
Petjada ecològica
Diatoms
Wetlands
Pyrenees
Ecological footprint
Descripción
Sumario:High mountain mires are affected by anthropogenic activities such as livestock, which have changed land use, fragmented habitats, and affected the structure and functioning of aquatic communities such as diatoms. Diatoms in mires exhibit high diversity, with a significant proportion of rare and threatened species, making them vulnerable to livestock pressure. Despite their common use as indicators of ecological status, little is known about how overgrazing and trampling affect diatom communities. To assess the impact of livestock pressure, we conducted experiments in six high-mountain mires in the Pyrenees, where livestock exclusion fences were installed. We identified a total of 370 species belonging to 60 genera, with a maximum diversity per site of 77 species. The variables most influencing diatom composition were pH, elevation, Bryophyta cover, water cover, livestock pressure, and mire area. Our results indicated an impact on diatom composition at the two locations with higher livestock pressure; however, we observed no effects on species richness or the Shannon index, suggesting that diatom communities are resistant to livestock pressure. The pH was the most important environmental variable for diatom community composition, demonstrating a positive relationship with diatom richness. Livestock pressure in high mountain mires causes habitat fragmentation and increased dry density of the soil, making diatom communities more vulnerable to environmental changes. However, these communities exhibit notable resistance to significant pressure, with pH emerging as the most critical factor influencing their structure. Our study showed that high livestock pressure affects diatom communities in mires. Considering that a high percentage of diatom species are red-listed as vulnerable or endangered, it is important to protect mires to avoid loss of diversity.