Mediterranean coastal dune vegetation: Are disturbance and stress the key selective forces that drive the psammophilous succession?

摘要: Abstract Plant communities of coastal dunes are distributed along a characteristic sea-inland gradient. Generally, there is shift from annual and short height species with small leaves in the initial successional stages to perennial tall shrubs tough later phases. Assessing community-weighted mean (CWM) trait values used plant ecology describe ecosystem properties especially during succession. In particular, CSR (Competitive, Stress-tolerant, Ruderal strategy) classification allows us explore community functional shifts terms disturbance, stress competition selective forces. The basis psammophilous succession was studied based on following questions: (1) Can we circumscribe different types among Mediterranean dunes? (2) How do CWM vary environmental gradient? (3) What relative importance competition, disturbance processes assembling? (4) postulate that primary successions generally ruderality stress-tolerance? An explorative analysis groups performed by Non-Metric Multidimensional Scaling (NMDS) analysing nine morpho-functional traits measured for 45 taxa 880 dune plots localised Tuscany (central Italy, Europe). NMDS ordination showed scattered distribution psammophytes could not be delimited precise types. first axis has been interpreted as leaf economics because it correlated area (LA) dry matter content (LDMC), while second one size its correlation canopy height. Along gradient, pioneer upper beach were dominated ruderals (with lowest LDMC specific - SLA), well-adapted harsh conditions dunes. More distant sea, where ecological less extreme, late-successional backdunes characterised prevalence stress-tolerance. This study suggested have evolved single but multiple adaptive strategies showing high degree diversity complexity. Moreover, supported hypothesis R-strategists early S-strategists