Guangdong Province Gudoushan Flora

This paper is a preliminary opinion on the flora of the Spermatophyta in the Gudou Mountain Nature Reserve(GMNR). GMNR is located at Jiangmen City, middle-southern Guangdong Province, with an area of 1157.5hm . The range of the reserve is a transitional region of South China tropics towards Lower-subtropics.In GMNR, so far a total of 1030 Vascular species in 536 genera of 169 families have been listed, 141families, 486 genera, 949 species (including intermination taxa, similarity hereinafter ) of the Spermatophyta, including 4 families, 4 genera, and 7 species of the Gymnospermae, and 137 families, 482 genera, 942 species of theAngiospermae ------ The Dicotyledonae 117 families, 374 genera, 755species, andthe Monocotyledonae 20 families, 108 genera, 187 species.The typical familes which hold a predominate status in forests are Lauraceae, Theaceae, Fagaceae, Aquifoliaceae, Symplocaceae, Myrsinaceae, Smilacaceae, Hamamelidaceae, Magnoliaceae, Elaeocarpaceae, Caprifoliaceae, most of which are of tropical and subtropical elements. Those fmilies also are the dominants in Guangdong flora, which indicates GMNR flora belongs to the most part of Guangdong flora. The 486 genera are devided into 13 types and 14 subtypes of geographical elements. Analysis of the floristic composition and the geographical elements shows that the flora has a complex composition dominated by tropical elements. Floristic analyses indicate that influences of the tropical flora and of the temperate flora are quite strong upon the GMNR flora, and the former is some stronger.On comparing the composition of its flora with some neighbouring floras, GMNR is most similar to Lianhua Mountain and Dinghu Mountain, the representative flora of the "Southern Subtropical Region". The tropical elements in GMNR flora are obviously less than those in the Jianfengling flora which is the "Northern Tropic Region", and the temperate ones less than those in the Lushan Mountain flora and the Jiulong Mountain flora, the representative flora of the "Middle Subtropical Region".As shown by the coefficient of similarity of flora and the clustering analysis of geographical elements, GMNR flora has a close relationship with others in Guangdong, such as the flora of Lianhua Mountain, Dinghu Mountain, Qimuzhang and Chebaling, and the influences of tropic elements on those flora become less and less with the latitude's increase. As far as the relationship between GMNR flora and other flora outside of Guangdong Province, the analysis shows that GMNR is more similar to Jianfengling than to Lushan Mountain an Jiulong Mountain.So, the author thinks GMNR is Floristically a transitional zone from the tropic to subtropic, and it should be a part of East-Asia region, belonging to the "Paleotropic Kingdom".Based on the difference among those flora in Guangdong Province, the author draws a conclusion that the boundary between the "Middle Subtropic" and the "Southern Subtropic" in Guangdong Province begins at Lianshan County(24?20' N)IVat west, and ends at Dapu County(24?30' N) at east, and the boundary between the tropic and the "Southern Subtropic" begins at Lianjiang County at west, pass Yangjiang and then extend to the seaside of Taishan. According to this conclusion, GMNR is on the verge of the "Northern tropic", closely nearby the "Southern Subtropic".