Abstract:

On account of the Cupressus gigantea is in severe danger,The relationship between the endangered conditions and the conditions of bearing fruit、morphological characters、vigor、damaged conditions、germination rate are studied through field investigation and TTC measurement of seed vigor in three groups(Lang County section in Brahmaputra , Milin and Linzhi County)of C. gigantea in natural conditions. The result shows: 70%～80% of the mature trees are fruitless or less fruit, and a health cone contains 58 seeds on average; Most trees are harmfully logged, and the seeds are severely injured by diseases、birds and mice. All of these are the exterior factors that induce C. gigantea to be in severe danger. Whereas, the seed vigor is an important internal factor,but the maximum of which is 39.8% and the average is only up to 34.6%, which is far lower than that of Pinus koraiensis and Cunninghamia lanceolata. The low germination is another important internal factor, the average of which is only 32.6%. The seed quality and the habitat conditions of temperature and humidity are bad for the individual reproducing and population dispersion of C. gigantea.

Key words: Cupressus gigantea, seed vigor, being endangered