Morphological, anatomical, biochemical and physiological traits of sun and shade leaves of adult Quercus ilex, Phillyrea latifolia and Pistacia lentiscus shrub species co-occurring in the Mediterranean maquis at Castelporziano (Latium) were studied. Fully expanded sun leaves had 47% (mean of the three species) greater leaf mass area (LMA) and 31% lower specific leaf area (SLA) than shade leaves. Palisade parenchyma thickness contributed on an average 42% to the total leaf thickness, spongy layer 43%, upper epidermal cells 5%, and upper cuticle thickness 3%. Stomatal size was greater in sun (25.5 mu m) than in shade leaves (23.6 mu m). Total chlorophyll content per fresh mass was 71% greater in shade than in sun leaves, and nitrogen content was the highest in sun (13.7 mg g(-1)) than in shade leaves (11.8 mg g(-1)). Difference of net photosynthetic rates (P (N)) between sun and shade leaves was 97% (mean of the three species). The plasticity index (sensu Valladares et al., New Phytol 148:79-91, 2000a) was the highest for physiological leaf traits (0.86) than for morphological, anatomical and biochemical ones. Q. ilex had the highest plasticity index of morphological, anatomical and physiological leaf traits (0.37, 0.28 and 0.71, respectively) that might explain its wider ecological distribution. The higher leaf plasticity of Q. ilex might be advantageous in response to varying environmental conditions, including global change

-Coppices of Castanea sativa Miller (1,5,7,10,12,17,23,26, and 30 years old stands) were investigated. Total basal area (BA) ranged from 4.9 ± 1.9 m 2 ha -1 (1 year old stands) to 41.0 ± 2.3 m 2 ha -1 (30 years old stands), and Leaf Area Index (LAI) from 0.18 ± 0.08 m 2 m -2 (1 year old stands) to 5.00 ± 0.22 m 2 m -2 (12 years old stands). Morphological and physiological leaf traits were analysed in 5 (YC) and 23 years old stands (OC) to point out the functional responses to clearing impact. The results pointed out the high productivity of C. sativa in the Park, due to favourable climatic and soil conditions. Significant differences of morpho-physiological leaf traits between YC and OC stands were observed during the last period of the vegetative cycle; it could be due to the higher efficiency in resource use of YC leaves than OC.