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Conservative nutrient use by big-leaf mahogany (Swietenia macrophylla King) planted under contrasting environmental conditions

Formally Refereed
Download (PDF 802 KB): https://research.fs.usda.gov/download/treesearch/46985.pdf

Abstract

We analyzed the nutritional composition and isotope ratios (C and N) of big-leaf mahogany (Swietenia macrophylla King) leaves in plantations established on contrasting soils and climates in Central America (State of Quintana Roo, Yucatan, Mexico) and South America (State of Para, Brazil). The objective was to determine the adaptability of this species to large differences in nutrient availability and rainfall regimes. Nutrient concentrations of leaves and soils were determined spectrophotometrically, and isotope ratios were measured using mass spectrometric techniques.In Para soils were sandier, and acidic, receiving above 2000 mm of rain, whereas in Quintana Roo soils were predominantly clayey, with neutral to alkaline pH due to the underlying calcareous substrate, with about 1300 mm of rain. Leaf area/weight ratio was similar for both sites, but leaves from Quintana Roo were significantly smaller. Average N and K concentrations of adult leaves were similar, whereas Ca concentration was only slightly lower in Para in spite of large differences in Ca availability. Leaves from this site had slightly higher P and lower Al concentrations. Differences in water use efficiency as measured by the natural abundance of 13C were negligible, the main effect of lower rainfall in Quintana Roo seemed to be a reduction in leaf area. The N isotope signature (sigma 15N) was more positive in Para than in Quintana Roo, suggesting higher denitrification rates in the former. Results reveal a calciotrophic behavior and a remarkable capacity of mahogany to compensate for large differences in soil texture and nutrient availability.

Citation

Medina, E.; Cuevas, E.; Lugo, A.E.; Terezo, E.; Jimenez-Osornio, J.; Macario-Mendoza, P.A.; Montanez, P. 2014. Conservative nutrient use by big-leaf mahogany (Swietenia macrophylla King) planted under contrasting environmental conditions. Revista Arvore. 38(3): 479-488.