Elemental stoichiometry and compositions of weevil larvae and two acorn hosts under natural phosphorus variation

Huawei Ji,Chunjiang Liu,Baoming Du

doi:10.1038/srep45810

Abstract

To understand how different trophic organisms in a parasite food chain adapt to the differences in soil nutrient conditions, we investigated stoichiometric variation and homeostasis of multiple elements in two acorn trees, Quercus variabilis and Quercus acutissima, and their parasite weevil larvae (Curculio davidi Fairmaire) at phosphorus (P)-deficient and P-rich sites in subtropical China where P-rich ores are scattered among dominant P-deficient soils. Results showed that elemental stoichiometry and compositions of both acorns and weevil larvae differed significantly between P-deficient and P-rich sites (p < 0.05), with the largest contribution of acorn and weevil larva P in distinguishing the stoichiometric compositions between the two site types. The two acorn species were statistically separated by their acorn elemental stoichiometry and compositions (p < 0.05), but no difference was observed on weevil larvae between the two acorn species. P was one of the few elements that were non strict homeostasis in both acorns and weevil larvae. These findings highlight the importance of both environmental influence in elemental stoichiometry and composition and physiological regulations of nutritional needs in organisms and provide possible stoichiometric responses of both plants and animals to P loading, a worldwide issue from excess release of P into the environment.

Highlights

To understand how different trophic organisms in a parasite food chain adapt to the differences in soil nutrient conditions, we investigated stoichiometric variation and homeostasis of multiple elements in two acorn trees, Quercus variabilis and Quercus acutissima, and their parasite weevil larvae (Curculio davidi Fairmaire) at phosphorus (P)-deficient and P-rich sites in subtropical China where P-rich ores are scattered among dominant P-deficient soils
The understandings on ecological stoichiometry of geologic P variation require the examination of organisms at different trophic levels and on all life elements that are typically categorized by their biological functions, such as structure (C, N, P, S, Mg and Ca), electrochemistry (Na, K, P and Mg), mechanics (Ca, Mg and P), and catalysis (Fe, Cu, Zn and Mn)[4,29]
We examined the stoichiometric elemental compositions of two acorn species, Quercus variabilis and Quercus acutissima, and associated parasite weevil larvae (Curculio davidi Fairmaire) that complete their last developmental stage in a single host acorn, in Central Yunnan Plateau, subtropical China

Summary

Introduction

To understand how different trophic organisms in a parasite food chain adapt to the differences in soil nutrient conditions, we investigated stoichiometric variation and homeostasis of multiple elements in two acorn trees, Quercus variabilis and Quercus acutissima, and their parasite weevil larvae (Curculio davidi Fairmaire) at phosphorus (P)-deficient and P-rich sites in subtropical China where P-rich ores are scattered among dominant P-deficient soils. We hypothesized that (i) both acorns and weevil larvae would have significant interspecific and intraspecific variations in elemental stoichiometry and compositions and nutrient-based stoichiometric traits through long-term adaptation to natural soil P variation, (ii) P would be the dominant element influencing the intraspecific variations of the acorn and weevil larva stoichiometric composition between the two site types of contrasting P, (iii) the degree of stoichiometric homeostasis would differ among different stoichiometric traits, between two acorn species, and between acorns and weevil larvae due to different nutritional demands and biological functions by elements, species, and trophic levels

Methods

Results

Conclusion