Optical properties of juniper and lentisk canopies in a coastal Mediterranean macchia shrubland.

Light absorbance and reflectance were measured on representative shrubs of two dominant shrub species (Pistacia lentiscus and Juniper phoenicea) of coastal Mediterranean macchia ecosystems located in Sardina (Italy). An array of 64 calibrated photodiodes was adopted for both calculations of Leaf Area Index and canopy transmittance of photosynthetic active radiation. PAR and NIR reflectance of canopies having similar LAI allowed to establish peculiar optical properties for each species. Lentisk reflected twice as much as juniper in the 700-1100 spectral region. Water indexes of the two species were also different in relation to leaf water content and red edge amplitude appeared to be related with chlorophyll content. Epidermis and mesophyll structures of the two examined species are shown.