LAUREL FORESTS IN TENERIFE, CANARY-ISLANDS - THE VERTICAL PROFILES OFLEAF CHARACTERISTICS

Different anatomical and physiological parameters were determined in l eaves of three tree species of a laurel forest in which the dominant t rees were Laurus azorica (Seub.) France, Persea indica (L.) Spreng. an d Myrica faya Ait. Samples were taken at different layers from the top down to the lower part of the canopy. The specific leaf weight, leaf thickness, and water potential (in absolute values) decreased down thr ough the canopy and also the chlorophyll content expressed by unit lea f area, on the contrary the leaf area increased. These features togeth er with the change in the chlorophyll a/b ratio, denote the adjustment of the leaves to the different microclimatic conditions in every laye r. Differences among the species are also shown. These changes should be taken into account for the interpretation of other physiological pa rameters not only at leaf level but also at the level of stand.