Pattern of biodiversity along latitude gradients is one of the basic issues in the biodiversity studies. The latitude gradients include several factors′ such as water and thermal conditions, anthropogenic impacts and so on. Especially the latitude gradient incorporates multiple resource gradients which vary continuously differently. Species diversity which varies with latitude gradients of herbaceous plants in Guangdong province was investigated and analyzed in this paper. The results showed that: a total of 190 herb species belonging to 67 families and 147 genera were recorded in midsubtropical areas, 179 herb species belonging to 65 families and 143 genera, 42 herb species belonging to 15 families and 41 genera in south subtropical and north tropical areas, respectively. Gramineae occupies an important role in this area. Dicranopteris dichotoma occupies the dominant position in midsubtropical and south subtropical areas, but it was Eupatorium odoratum and Conyza canadensis in north tropical areas from the respect of quantitative characteristics. Richness index in artificial forest was from 1.313 to 1.459 and diversity index was from 1.260 to 1.328, they all showed inverted “V” trend with the decreasing latitude, but increased with latitude decreasing in natural forest, bamboo forest and bush fallow. In general, the results showed a low levels of herbaceous′ diversity in Guangdong province.
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