Studies of Ecological Stoichimetry of plant species are important for the carbon and nutrient dynamics in terrestrial ecosystems, especially in the context of climate change. Subtropical evergreen forest is one of the most important vegetation types for the carbon balance research and covers most of the southern China. However, the ecological stoichimetry analyses on subtropical evergreen forests are still limited. Based on the accumulated basal areas, we selected 26 dominant woody species of the Castanopsis eyrei - Schima superba community, distributed in the permanent 24 ha-plot of Gutian mountain in southeastern China, and measured the C, N, P, K, Ca, Mg contents in leaf, twig, branch, and stem of these species and the chemical and texture characteristics of the corresponding soil samples. We analyzed the correlations between different chemical contents in plants and soils and further investigated the ecological stoichiometry characteristics of these plant species with their distributions within the large permanent plot.
Results/Conclusions
The results indicate that the C content in each organ is negatively related to the contents of N, P, K, Ca, Mg. N and P are significantly correlated in leaves (r2=0.69) and twigs (r2=0.46). P contents are significantly correlated to K in twigs (r2=0.70) and branches (r2=0.71). And Ca and Mg are significantly correlated in leaves (r2=0.79), twigs (r2=0.57), and branches (r2= 0.61). Soil N and P contents are significantly correlated (r2=0.85) and both are positively correlated to the humus content. Stone component increases significantly with the elevation. The average leaf N:P is 25.3 for the 28 dominant woody species. Considering the low soil P content, 0.15g/kg, P may limit the plant growth in this area. Taking into account the species, dbh class, and soil texture and chemical characteristics, leaf N is mostly influenced by the species type, while species together with soil pH are the most important factors influencing leaf P. By comparing the species chemical contents with the corresponding abundances in the plot, leaf P and N:P are both significantly correlated with the species abundance within the large plot, the lower the leaf P (the higher the N:P), the more in abundance.
