The relative importance of disturbance and environmental stress at local and regional scales in French coastal sand dunes
Language
en
Article de revue
This item was published in
Journal of Vegetation Science. 2008-01-29, vol. 19, n° 4, p. 493-502
Wiley
English Abstract
Questions: 1. Is there a primary role of disturbance at local scale and of environmental stress at regional scale? 2. Does disturbance increase or decrease environmental stress at local scale? Location: The Atlantic coastal ...Read more >
Questions: 1. Is there a primary role of disturbance at local scale and of environmental stress at regional scale? 2. Does disturbance increase or decrease environmental stress at local scale? Location: The Atlantic coastal dune system of the Aquitaine Region (France). Methods: Species biomass and 16 environmental variables were sampled in 128 quadrats along a local beach-inland gradient and a regional North-South gradient. Environmental data were analysed with ANOVAs and vegetation-environment relationships with Canonical Correspondence Analysis. Results: At the local scale community composition was primarily driven by disturbance due to sand burial, whereas water and nutrient stress better explained regional differences. However, random biogeographical events are very likely to also affect community composition at the largest scale. The main interaction between environmental stress and disturbance was the mitigation of nutrient stress induced by disturbance at a local scale. This was due to a positive direct effect of sand burial and a positive indirect effect of wind (decrease in VPD by ocean spray). Although wind had also a significant effect on soil conductivity and pH, there was no evidence that these factors had any role in community composition. Conclusions: Our results support the hypothesis that disturbance had a primary role at local scale and environmental stress at regional scale but further research is needed to separate the effect of stress from that of dispersal at regional scale. We also demonstrated that environmental stress in primary succession may not always decline with decreasing disturbance.Read less <
Keywords
CCA
NUTRIENT STRESS
SAND BURIAL
RELATION VÉGÉTATION - ENVIRONNEMENT
DUNE DE SABLE
English Keywords
COMMUNITY COMPOSITION
PRIMARY SUCCESSION
VEGETATION-ENVIRONMENT RELATIONSHIP
WATER STRESS
WIND
STRESS NUTRITIF
Origin
Hal imported