Aims Tsuga chinensis var. tchekiangensis is a species with a small geographic distribution in the subtropical forests in eastern China. The species has been listed as Chinese national third protective plant. Our objective was to investigate the differences and correlations of metal element contents in plant and forest soil of T. chinensis var. tchekiangensis in different community types in Jiulongshan Nature Reserve, Zhejiang Province, China. Findings will provide a scientific basic for feasible in situ and ex situ conservation of the species.
Methods Forty representative plots (10 m × 10 m) were investigated along different ridges from low to high altitude. The community types of these plots were identified, and the groups of tree relationships were established based on TWINSPAN. Twelve metal elements of root, stem, bark and leaf of T. chinensis var. tchekiangensis samples and forest soil were measured by ICP-AES. Soil factors such as pH, water content, organism content and electrical conductivity were also measured. Differences of metal element contents were analyzed among different community types and organs. The correlation among different metal element contents of T. chinensis var. tchekiangensis and soil nutrient factors were analyzed and compared.
Important findings Based on the investigations and results of TWINSPAN classification, the plots were classified into five communities. Differences among metal element contents of plant and soil in different community types were determined. The contents of plant elements such as K, Ca, Fe, Mg, Ba and Cr were higher in community II and V, and most soil elements were highest in community II. The content of Ca, K, Mg, Fe and Mn were higher in plant, and Al and Fe were higher in soil. The content of metal elements among different organs was different, and their change tendencies and variation degrees were discordant. Enrichment coefficient and correlation analysis showed that the absorption of Mg and Zn, as well as Fe and Al by T. chinensis var. tchekiangensis was similar; however, most plant elements had no correlation with soil elements.