Publications des scientifiques de l'IRD

Perez H. R., Borrel G., Leroy Céline, Carrias J. F., Corbara B., Srivastava D. S., Cereghino R. (2018). Simulated drought regimes reveal community resilience and hydrological thresholds for altered decomposition. Oecologia, 187 (1), p. 267-279. ISSN 0029-8549.

Titre du document
Simulated drought regimes reveal community resilience and hydrological thresholds for altered decomposition
Année de publication
2018
Type de document
Article référencé dans le Web of Science WOS:000431668500023
Auteurs
Perez H. R., Borrel G., Leroy Céline, Carrias J. F., Corbara B., Srivastava D. S., Cereghino R.
Source
Oecologia, 2018, 187 (1), p. 267-279 ISSN 0029-8549
Future climate scenarios forecast a 10-50% decline in rainfall in Eastern Amazonia. Altered precipitation patterns may change important ecosystem functions like decomposition through either changes in physical and chemical processes or shifts in the activity and/or composition of species. We experimentally manipulated hydroperiods (length of wet:dry cycles) in a tank bromeliad ecosystem to examine impacts on leaf litter decomposition. Gross loss of litter mass over 112 days was greatest in continuously submersed litter, lowest in continuously dry litter, and intermediate over a range of hydroperiods ranging from eight cycles of 7 wet:7 dry days to one cycle of 56 wet:56 dry days. The resilience of litter mass loss to hydroperiod length is due to a shift from biologically assisted decomposition (mostly microbial) at short wet:dry hydroperiods to physicochemical release of dissolved organic matter at longer wet:dry hydroperiods. Biologically assisted decomposition was maximized at wet:dry hydroperiods falling within the range of ambient conditions (12-22 consecutive dry days) but then declined under prolonged wet:dry hydroperiods (28 and 56 dry days. Fungal:bacterial ratios showed a similar pattern as biologically assisted decomposition to hydroperiod length. Our results suggest that microbial communities confer functional resilience to altered hydroperiod in tank bromeliad ecosystems. We predict a substantial decrease in biological activity relevant to decomposition under climate scenarios that increase consecutive dry days by 1.6- to 3.2-fold in our study area, whereas decreased frequency of dry periods will tend to increase the physicochemical component of decomposition.
Plan de classement
Sciences du milieu [021] ; Sciences du monde végétal [076] ; Etudes, transformation, conservation du milieu naturel [082]
Description Géographique
GUYANE FRANCAISE
Localisation
Fonds IRD [F B010072851]
Identifiant IRD
fdi:010072851
Contact