Stoichiometric homeostasis of vascular plants in the Inner Mongolia grassland
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Stoichiometric homeostasis, the degree to which an organism maintains its C:N:P ratios around a given species- or stage-specific value despite variation in the relative availabilities of elements in its resource supplies, is a key parameter in ecological stoichiometry. However, its regulation and role in affecting organismal and ecosystem processes is still poorly understood in vascular plants. We performed a sand culture experiment and a field nitrogen (N) and phosphorus (P) addition experiment to evaluate the strength of N, P and N:P homeostasis in higher plants in the Inner Mongolia grassland. Our results showed that homeostatic regulation coefficients (H) of vascular plants ranged from 1.93 to 14.5. H varied according to plant species, aboveground and belowground compartments, plant developmental stage, and overall plant nutrient content and N:P ratio. H for belowground and for foliage were inversely related, while H increased with plant developmental stage. H for N (H N) was consistently greater than H for P (H P) while H for N:P (H N:P) was consistently greater than H N and H P. Furthermore, species with greater N and P contents and lower N:P were less homeostatic, suggesting that more homeostatic plants are more conservative nutrient users. The results demonstrate that H of plants encompasses a considerable range but is stronger than that of algae and fungi and weaker than that of animals. This is the first comprehensive evaluation of factors influencing stoichiometric homeostasis in vascular plants.
KeywordsEcological stoichiometry N:P ratio Developmental stages Steppe Plant functional groups
We are grateful to the Inner Mongolia Grassland Ecosystem Research Station (IMGERS) for providing the experimental sites and elemental analysis. This work was supported by the Key Project of National Natural Science Foundation of China (NSFC, 30830026), the Innovative Research Group Project of NSFC (30821062), and the State Key Basic Research Development Program (2007CB106801). J. Elser acknowledges support from the National Science Foundation (DEB-0618193). We would like to thank R.W. Sterner, H. Heilmeier and two anonymous reviewers for their comments that greatly improved earlier versions of this manuscript. The main participants for the field experiment included Lishi Zhou, Fumei Lv, Hao Yang, Yanshu Liu, Deliang Kong, Xiaotao Lv, Qiang Li, Jianjun Chen, and Fuli Zhang; they are gratefully acknowledged.
- Bremner JM (1996) Nitrogen: total. In: Sparks DL et al (eds) Methods of soil analysis. Part 3. Chemical methods. Soil Science Society of America and American Society of Agronomy, Madison, pp 1085–1123Google Scholar
- Hoagland R, Arnon DI (1950) The water culture method for growing plants without soil. Circular 347, California Agricultural Experiment Station, College of Agriculture. University of California, BerkeleyGoogle Scholar
- Jensen MH, Collins WL (1985) Hydroponic vegetable production. Hortic Rev 7:483–558Google Scholar
- Kuo S (1996) Phosphorus. In: Sparks DL et al (eds) Methods of soil analysis. Part 3. Chemical methods. Soil Science Society of America and American Society of Agronomy, Madison, pp 869–920Google Scholar
- Levi MP, Cowling EB (1969) Role of nitrogen in wood deterioration VII. Physiological adaptation of wood-destroying and other fungi to substrates deficient in nitrogen. Phytopathology 59:460–468Google Scholar
- Nakano S (1994) Carbon:nitrogen:phosphorus ratios and nutrient regeneration of a heterotrophic flagellate fed on bacteria with different elemental ratios. Arch Hydrobiol 129:257–271Google Scholar
- Persson J, Fink P, Goto A, Hood JM, Jonas J, Kato S (2010) To be or not to be what you eat: regulation of stoichiometric homeostasis among autotrophs and heterotrophs. Oikos doi: 10.1111/j.1600-0706.2010.18545.x
- Sterner RW, Elser JJ (2002) Ecological stoichiometry: the biology of elements from molecules to the biosphere. Princeton University Press, PrincetonGoogle Scholar
- Vogel S (1998) Academically correct biological science. Am Sci 86:504–506Google Scholar