A Biodiversity Study on the Pteridophytes from Guangzhou City, Guangdong
广州市蕨类植物物种多样性研究

In order to understand the modern pteridoflora of Guangzhou, Guangdong Province, we briefly reviewed the recorded pteridophytes in history and made extensive explorations in this area in the last two and a half years. As a result, 176 species belonging to 82 genera in 37 families are now recorded for Guangzhou. Three species, Dicranopteris gigantea, Hymenophyllum spinosum, and Dryopteris gymnosora, are newly recorded from Guangdong. The five species-rich families are Thelypteridaceae, Dryopteridaceae, Polypodiaceae, Athyriaceae and Pteridaceae. The geographical distribution of the species shows that this flora mainly consists of tropical & subtropical Asian and eastern Asian elements but lacks local endemics. About 80% of the species of this flora grow in humid habitats of dense forest, about 20% occur in relatively dry habitats such as sparse forest and shrub in roadsides, and two species are hydrophytic. Regarding the horizontal distribution in Guangzhou, only a very small proportion of the species occurs in the southern and central areas, but about 90% grow in the montane area of Conghua in northeastern Guangzhou, from which 74 species only occur in Conghua. Within Guangzhou, the abundance of the 176 species can be classified in four groups, i.e., 33 species are Cop (copiosae)2, 48 are Cop1, 53 are Sp (sparsal) and 41 are Sol (solitariae). Fifteen species, i.e., Phlegmariurus austrosinicus, Angiopteris fokiensis, Hymenophyllum spinosum, Alsophila denticulata, A. metteniana, A. podophylla, A. spinulosa, Ceratopteris thalictroides, Diplazium tomitaroanum, Dictyocline mingchegensis, Metathelypteris adscendens, Leptogramma scallanii, Brainea insignis, Woodwardia prolifera and Arachniodes nigrospinosa, are evaluated as rare and endangered in Guangzhou but not under any effective protection at present.