Aims Mainly distributed in China, subtropical evergreen broad-leaved forest is one of important vegetation types in the world. Here we report preliminary results of floristic characteristics, community composition, vertical structure, size class structure, and spatial structure of Gutianshan(GTS) forest plot.
Methods We established a 24-hm2 (600 m×400 m) forest permanent plot from November, 2004 to September, 2005 in mid-subtropical evergreen broad-leaved forest of Gutianshan Nature Reserve, China. Following the standard census procedure of the Centre for Tropical Forest Science (CTFS), all free-standing trees ≥1 cm in diameter at breast height (DBH) in the forest were mapped, tagged and identified to species. We employed software R 2.6.0 to analyze our data.
Important findings The results of floristic characteristics indicates that the tropical elements are more than temperate elements. At family level, the proportion of the pantropic type is the greatest (28.6%), the number of the tropic elements are more than temperate ones (24/13). At genus level,there are 53 tropic genera and 44 temperate ones. As for community composition, there are 159 species, 103 genera and 49 families, 140 700 individuals in total. The evergreen tree species in community are dominant (i.e. 91 species, total relative dominance is 90.6%, importance value is 85.6%, accounts for 85.9% of the total abundance). GTS forest plot is typical mid-subtropical evergreen broad-leaved forest, which displays characteristics of both temperate deciduous broad-leaved forest and tropical rain forest. On the one hand, community composition has obvious dominant species, which is similar to temperate deciduous broad-leaved forest. There are 3 mostly dominant species, Castanopsis eyrei, Schima superba and Pinus massoniana. Large numbers of rare species (59 rare species, equal to or less than one tree per hm2) in the community account for 37.1% species richness, which is similar to tropical rain forest. Vertical structure is composed of canopy layer (63 species), sub-tree layer (70 species), shrub layer (26 species).The structure of DBH size class of all species in the plot generally appears reverse 'J' shape, which indicates successful community regeneration. Spatial distribution of several dominant species, from small to adult tree or old tree, shifts from closer aggregation to looser aggregation, and shows different habitat preference. Finally, we compare the large plot approach with conventional sampling method.