INSECT DAMAGE TO CONES AND OTHER MORTALITY FACTORS LIMITING NATURAL REGENERATION POTENTIAL OF SWISS STONE PINE (PINUS-CEMBRA L) IN THE NORTHERN FRENCH ALPS

A seed cone population of Swiss stone pine was surveyed from flower bu d burst to cone maturation during 1999-1993. The potential seed crop w as estimated to decrease by 84% of the initial value. Mortality was ma inly caused by abiotic factors during the first year of cone developme nt while cone insects caused most damage to second-year cones. The con e entomofauna only included three phytophagous species, and largely di ffered from the fauna observed in cones of other Alpine conifers.