Rosero-Lopez D., Walter M. T., Flecker A. S., De Bievre B., Osorio R., Gonzalez-Zeas D., Cauvy-Fraunie S., Dangles Olivier. (2022). A whole-ecosystem experiment reveals flow-induced shifts in a stream community. Communications Biology, 5 (1), p. 420 [8 p.].
Titre du document
A whole-ecosystem experiment reveals flow-induced shifts in a stream community
Rosero-Lopez D., Walter M. T., Flecker A. S., De Bievre B., Osorio R., Gonzalez-Zeas D., Cauvy-Fraunie S., Dangles Olivier
Source
Communications Biology, 2022,
5 (1), p. 420 [8 p.]
The growing threat of abrupt and irreversible changes to the functioning of freshwater ecosystems compels robust measures of tipping point thresholds. To determine benthic cyanobacteria regime shifts in a potable water supply system in the tropical Andes, we conducted a whole ecosystem-scale experiment in which we systematically diverted 20 to 90% of streamflow and measured ecological responses. Benthic cyanobacteria greatly increased with a 60% flow reduction and this tipping point was related to water temperature and nitrate concentration increases, both known to boost algal productivity. We supplemented our experiment with a regional survey collecting > 1450 flow-benthic algal measurements at streams varying in water abstraction levels. We confirmed the tipping point flow value, albeit at a slightly lower threshold (40-50%). A global literature review broadly confirmed our results with a mean tipping point at 58% of flow reduction. Our study provides robust in situ demonstrations of regime shift thresholds in running waters with potentially strong implications for environmental flows management. Experimental stream manipulation in a mountain river system in the tropical Andes initiates a regime shift of benthic cyanobacteria. This whole-ecosystem experiment in conjunction with a global synthesis reveal regime shift tipping points dependent upon freshwater streamflow.
Plan de classement
Sciences du milieu [021]
;
Limnologie biologique / Océanographie biologique [034]
;
Ecologie, systèmes aquatiques [036]
Description Géographique
EQUATEUR ; ANDES ; ZONE TROPICALE ; MONDE ; CAYAMBE COCA PARC NATIONAL ; CHALPI GRANDE BASSIN VERSANT
