Nutrient resorption and adaptation strategy characteristics of two plantations in subtropical China­—Ecological stoichiometry

Abstract Background and aims Leaf nutrients resorption is critical for considerations of how plants use and recycle nutrients in terrestrial ecosystems. However, information on nutrient resorption and adaptation strategies of the same plant species growing in areas with different geological backgrounds remain poorly understood. Methods We investigated one natural plantation of Pinus yunnanensis Franch. (PY) and one introduced plantation of Eucalyptus maideni F. Muell. (EM) growing under the same climatic conditions but different geological backgrounds (limestone, karst area vs clasolite, non-karst area) in Yunnan Province, China. The C, N, and P concentrations, nutrient restriction, nutrient resorption efficiency, stoichiometric homeostasis, and plant adaptation strategy indicators were investigated. Results The results showed that soil concentrations of C, N, and P were significantly higher in the karst areas compared to the non-karst areas both of the two plantations. Elemental composition of specific plant organs differed significantly between the two sites, while within sites, different organs showed different elemental compositions. In addition, leaf N: P ratios and leaf P resorption efficiencies indicated that plantations in subtropical China are mainly limited by P, which was more evident in the non-karst area. The PY plantation in both areas showed a “conservative consumption” nutrient use strategy, whereas the EM plantation in the two areas showed a “resource spending” nutrient use strategy. Conclusions Plants need to adapt physiologically and morphologically to the harsh conditions in karst areas, resulting in lower growth rates and biomass, more conservative nutrient use, and a high capacity to retain nutrients in the biomass. The findings of this study indicated that trees could synergistically accommodate leaf stoichiometry and nutrient resorption efficiencies in response to different soil types. Overall, our results provide support that the geological background should be considered during the process of vegetation restoration.