Leaf functional traits in Brachypodium pinnatum (L.) Beauv., Bromus erectus Hudson and Dactylis glomerata L. as indicators of resource availability in grassland communities

Brachypodium pinnatum, Bromus erectus and Dactylis glomerata are very common species in European semi-natural grasslands but have different life strategies: B. pinnatum and B. erectus, unlike D. glomerata, are stress-tolerant competitors of xeric, resource-poor habitats. The study was performed in spring and autumn of 2006, at two grassland sites (Regional Park of Monte Sole, Italy) having similar microclimatic condition but different resource availability. Specific Leaf Area (SLA), Leaf Dry Matter Content (LDMC), Leaf Nitrogen Concentration (LNC) and Leaf Lignin Content (LLC) were measured on the three species in each of the two sites. The variations of LNC between seasons, and of SLA, LDMC an LLC between species were highly significant. D.glomerata, with the highest SLA and the lowest LDMC and LLS values, fits the model of fast-growing species. B. pinnatum and B. erectus, with lower SLA and higher LDMC and LLS values, tend towards the behaviour of slow-growing species. SLA and LDMC are the major traits chracterizing inter-site differences.