69. Comparative Ecophysiology of Seed Germination Strategies ßç the Seven Pine Species Naturally Growing ßç Greece

Seven out of the eleven European pine species grow naturally ßç Greece. Pinus há/epensis, Ñ. brutiá and Ñ. pineá are 10w-altitude, typical Ìedßteðaneaç species. The Greek ÑÏÑþatßïçs of Ñ. nigrá, Ñ. he/dreichii, Ñ. sy/vestris and Ñ. peuce grow ßç high altitudes and are 10cated at the southern limits of their natural world dßstÞbutiïçs. Seed germination data concerning temperature dependence as well as light and/ or stratification requirements are presented and discussed ßç relation to the individua1 species characteristics. Fire resilient Ñ. há/epensis and Ñ. brutiá are characterized by quite 10w germination ßç the dark, throughout their optimal temperature range (10-20°C); ßç addition, their germination is photosensitive (white-light promoted and far-red inhibited). Prolonged stratification is always beneficial to Ñ. brutiá but detrimental to Ñ. há/epensis seeds. Germination of Ñ. pineá seeds is also slow but indifferent to light conditions and restÞcted éï a very çaðïw temperature range, around 20°C. Ñ. nigrá seeds are fast germinating over a wide temperature range and rather indifferent to light. Germination of the deeply dormant Ñ. he/dreichii seeds as well as of the less dormant ones of Ñ. sy/vestris requires light and/or stratification. ÂÕ combining germination data for each species with the Ñarticþar seasons of seed dispersal and the climatic conditions of the respective habitats, timing schedules of seed germination and subsequent seedling emergence ßç nature are proposed