Morphological and anatomical characteristics of leaf of Larix chinensis and their relationship to environmental factors in Taibaishan Mountain

The climatic indexes were calculated at variant elevation accor ding to the method of ecoclimatelogy.The morphological and anatomic leaf characteristics and their main affecting ecological factors of Larix chinensis,which distributes at 3 000～3 400 m in Taibaishan Mountain of Qinling Mountains,was studied by using the method of multivariate statistic.The morphological indexes are leaf thick,leaf number of every leaf brunch,and ratio between length and broad of leaf.The anatomic indexes are cuticle thick,upper epidermis thick,lower epidermis thick,endodermis thick,thick of transfusion tissue and vascular bundle,tracheid diameter,and ratio between thick of transfusion tissue and vascular bundle and leaf thick.The results showed following points.① Baileys index was essential factor that affected the ratio between length and broad of leaf and the epidermis cuticle thick of leaf of Larix chinensis.The ratio between length and broad of leaf tended to increase and the epidermis cuticle thick of leaf gradually getting thinner with the increasing of Baileys index.② The annual precipitation was essential factor affecting other morphological anatomic indexes.With the increasing of annual precipitation,these characteristics tended to be shorter or thinner.They are the leaf number of every brunch leaves,the leaf thick,the trachied diameter,the thick of transfusion tissue and vascular bundle of leaf,the endodermis thick,and the ratio between thick of transfusion tissue and vascular bundle and leaf thick.But the lower and upper epidermis thick of leaf was increasing gradually.③ The thick of mesophyll between lower and upper epidermis and endodermis in leaf middle,which were not obviously related to environmental factors,probably were more conservative character.