Publication Date:
2022-05-26
Description:
Author Posting. © Ecological Society of America, 2014. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Ecology 95 (2014): 2062–2068, doi:10.1890/13-1671.1.
Description:
Foliar nitrogen to phosphorus (N:P) ratios are widely used to indicate soil nutrient availability and limitation, but the foliar ratios of woody plants have proven more complicated to interpret than ratios from whole biomass of herbaceous species. This may be related to tissues in woody species acting as nutrient reservoirs during active growth, allowing maintenance of optimal N:P ratios in recently produced, fully expanded leaves (i.e., “new” leaves, the most commonly sampled tissue). Here we address the hypothesis that N:P ratios of newly expanded leaves are less sensitive indicators of soil nutrient availability than are other tissue types in woody plants. Seedlings of five naturally established tree species were harvested from plots receiving two years of fertilizer treatments in a lowland tropical forest in the Republic of Panama. Nutrient concentrations were determined in new leaves, old leaves, stems, and roots. For stems and roots, N:P ratios increased after N addition and decreased after P addition, and trends were consistent across all five species. Older leaves also showed strong responses to N and P addition, and trends were consistent for four of five species. In comparison, overall N:P ratio responses in new leaves were more variable across species. These results indicate that the N:P ratios of stems, roots, and older leaves are more responsive indicators of soil nutrient availability than are those of new leaves. Testing the generality of this result could improve the use of tissue nutrient ratios as indices of soil nutrient availability in woody plants.
Description:
Data are from Santiago et al. (2012), which was supported by
a grant from the Andrew W. Mellon Foundation to S. J.
Wright, a Smithsonian Institute Scholarly Studies grant to S. J.
Wright and J. B. Yavitt, and a University of California
Regent’s Faculty Fellowship to L. S. Santiago. L. A.
Schreeg was partially supported through a Marine Biological
Laboratory-Brown University SEED grant to Z. Cardon, S.
Porder, and L. A. Schreeg.
Keywords:
Barro Colorado Nature Monument, Panama
;
Forests
;
Nitrogen
;
N:P ratios
;
Phosphorus
;
Soil nutrient availability
;
Stoichiometry
;
Woody plants
Repository Name:
Woods Hole Open Access Server
Type:
Article
Format:
application/pdf
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