Nutrient allocation among plant organs across 13 tree species in three Bornean rain forests with contrasting nutrient availabilities
- 289 Downloads
Allocation of nitrogen (N) and phosphorus (P) among plant organs is an important factor regulating growth rate, which is a key ecological process associated with plant life-history strategies. However, few studies have explored how N and P investment in photosynthetic (leaves) and non-photosynthetic (stems and roots) organs changes in relation to depletion of each element. We investigated nutrient concentrations of plant organs in relation to whole-plant nutrient concentration (total nutrient weight per total biomass) as an index of nutrient status of each individual using the saplings of the 13 species in three tropical rain forests with contrasting N and P availabilities (tropical evergreen forests and tropical heath forests). We found a steeper decrease in foliar N concentration than foliar P concentration with decreasing whole-plant nutrient concentration. Moreover, the steeper decrease in foliar N concentration was associated with relatively stable N concentration in stems, and vice versa for P. We suggest that the depletion of N is associated with a rapid dilution of foliar N because the cell walls in non-photosynthetic organs function as an N sink. On the other hand, these species can maintain foliar P concentration by decreasing stem P concentrations despites the depletion of P. Our results emphasize the significance of non-photosynthetic organs as an N sink for understanding the variation of foliar nutrient concentrations for the tree species in the three Bornean rain forests with different N and P availabilities.
KeywordsCell walls Functional traits Mixed dipterocarp forests Nutrient productivity Photosynthetic and non-photosynthetic organs Tropical heath forests
We thank L. Ajon, P. Lagan, Y. Onoda, A. Hidaka, N. Imai, T. Seino, and K. Miyamoto for assisting our fieldwork and providing valuable suggestions. Permission to conduct our research was granted by the Sabah Forestry Department and the Sabah Parks. This study was supported by the Grant-in-Aid from the Japanese MESSC (22255002) to K.K. and by the Global Environment Research Fund D-1006 and 1-1403 of the Ministry of the Environment, Japan, to K.K.
- Aoyagi R, Imai N, Seino T, Kitayama K (2016) Soil nutrients and size-dependent tree dynamics of tropical lowland forests on volcanic and sedimentary substrates in Sabah, Malaysian Borneo. Tropics (accepted)Google Scholar
- Chua GLS, Koh BL, Lau S et al (1995) The nutrient status of the plateau heath forest on Gunung Keriong, Pahang, Peninsular Malaysia. J Trop For Sci 8:240–246Google Scholar
- Coomes DA (1997) Nutrient status of Amazonian caatinga forests in a seasonally dry area: nutrient fluxes in litter fall and analyses of soils. Can J For Res 27:831–839Google Scholar
- Field C, Mooney HA (1986) The photosynthesis–nitrogen relationship in wild plants. In: Givnish TJ (ed) On the economy of plant form and function. Cambridge University Press, Cambridge, pp 25–55Google Scholar
- Grime JP (1979) Plant strategies and vegetation processes. Wiley, ChichesterGoogle Scholar
- Hunt R (1978) Plant growth analysis. Edward Arnold, LondonGoogle Scholar
- R Core Team (2014) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. http://www.R-project.org/
- Seino T, Kitayama K, Lakim MB (2007) Floristic composition and stand structure of the mixed dipterocarp forest in Tawau Hills Park, Sabah, Malaysia. Sabah Park Nat J 8:63–82Google Scholar
- Sterner RW, Elser JJ (2002) Ecological stoichiometry: the biology of elements from molecules to the biosphere. Princeton University Press, PrincetonGoogle Scholar
- Tiessen H, Moir JO (1993) Characterization of available P by sequential extraction. In: Carter MR (ed) Soil sampling and methods of analysis, Lewis Publishers, pp. 75–86Google Scholar