DIVERSITY OF VINES IN SUBTROPICAL ZONE OF EAST CHINA

Subtropical Zone of East China (SZEC) covers the area from Tropic of Cancer to 34°N,including Chinese region of extra tropical evergreen broad leaved forest,where climate is warm and wet.Vines are very common in the area,but the ecology of vines is virtually a blank.Based on analysis of flora,breeding system,climbing mechanics and habit of vines in SZEC,the diversity of vines was studied.The results are as follows:(1)There are 611 clim bing species,belonging to 164 genera and 58 families,which account for 9.6%, 10.3% and 29.1% of the whole angiosperm flora in SZEC,respectively.The vine abundance of flora in SZECis higher than that (7%) in the temperate,less than that (19%) in the continental tropic.Lianas account for 72.3%,and vines 27.7%.(2)Vine flora composes mainly of small families and genera in SZEC.The number of families with 1～5 vine species is 39(67.2%) and the number of genera with 1～5 vine species is 136(82.9%).Although vine species are included in many families,the majority belongs to relatively few families.Thus 59.1% of the 611 vine species belong to 10 families (e.g.Vitaceae,Leguminosae,Ranunculaceae,Actinidiaceae,Cucurbitaceae and so on).(3)In the vine sexual systems the hermaphrodites account for 60.6%,the dioecious 30.8% and the monoecious 3.9%, and polygamous 4.7%.(4)Vine climbing mechanics are divided into 9 types:the stem twining (56.6%),the tendril curling (20.3%),the petiole curling (6.4%),the branch curling (0.8%),the thorn hooking (8.2%),the branch hooking (1.3%),the hook hooking (0.5%),the adventitious root adhering (4.9%) and the adhesive apparatus adhering (1.0%).(5) Vine flora in SZECis complex and is characterized by the dominance of tropical floral elements.According to the classification of the areal types by professor Wu Zhenyi(1991),vine genera may be divided into 13 areal types,among which the tropical elements account for 69.3%, the temperate elements only 28.1% and the endemic 2.6% in SZEC.