Abstract: Parent rock plays an important role in driving the nutrient content and characteristics of soils. In this study, we investigated the contents and stoichiometry of carbon, nitrogen, and phosphorus in areca plantation soil formed by different parent rocks, including volcanic, intrusive, metamorphic and sedimentary rock. The sampling sites are distributed in 11 cities and counties in Hainan Province. We examined the variations of soil nutrients among parent rocks and different soil layers. The results showed that soil nutrient status and stoichiometric characteristics of areca plantations were influenced by the factors related to the historical heritage of parent rocks. The contents of soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), and available nitrogen (AN) in soils developed from volcanic rocks were significantly higher than those in intrusive rocks, metamorphic rocks, and sedimentary rocks. The contents of total and available potassium (TK and AK) in soils developed from intrusive and sedimentary rocks were significantly higher than those in volcanic rocks and metamorphic rocks. The characteristics of the parent rocks affected the distribution of soil nutrients among soil profile. The contents of AN, AK, and DOC/AP in sedimentary rocks showed no differences among soil layers. The stoichiometric ratios of carbon, nitrogen and phosphorus showed the opposite variation between the soils developed from volcanic and sedimentary rocks, while that of carbon and phosphorus showed the same variation pattern. The higher SOC/TN and lower TN/TP in volcanic rocks indicated that the decomposition rate of organic carbon would be lower and that nitrogen availability was severely limited. The higher DOC/AN and lower AN/AP in sedimentary rocks indicated that the soil was richer in active organic carbon pool but poorer in available nitrogen, highlighting the limitation of N. In general, the contents of soil organic carbon, total nitrogen and available phosphorus were all at an optimal state, while the contents of total phosphorus (except for volcanic rock) and available potassium were mainly at a scarce state. To improve the soil nutrient content and its availability, and further mine the planting potential, the soils should be reasonably fertilized and scientifically managed according to different parent rocks.

Key words: parent rock, soil layer, soil nutrient, stoichiometric ratio, areca plantation, Hainan Province.