No Evidence that the Valuable Timber Species, Dalbergia retusa, Enhances Nutrient Cycling and Uptake by Neighboring Timber Species

ABSTRACT

The use of native species for timber plantations in the tropics has lately gained interest. Recent studies have shown that native tree plantations can have greater economic, and ecological benefits than non-native plantations. Facilitative nutritional interactions with nitrogen-fixing trees are a common practice used in hopes of enhancing nitrogen input. Dalbergia retusa and Terminalia amazonia are two neotropical species frequently used for timber extraction. In order to understand these species belowground interactions, we worked on 33 plots of the T. amazonia and D. retusa mixtures in the Agua Salud Project Native Species plantations in Panama. The objective of this study was to assess if soil biochemical properties under T. amazonia trees might be influenced by D. retusa in these mixtures. For this, soil samples were collected and analyzed for nitrogen pools, extractable cations and selected phosphorus constituents. Our results showed that nutrient concentrations were not significantly different below D. restusa and T. amazonia trees. Nonetheless, temporal and physicochemical characteristics of the plantation might be influencing the tree performance and should be considered for a better understanding of the nutrient dynamics in native tree plantations.

KEYWORDS:

• Nutrient cycling
• facilitation
• native plantations
• Terminalia amazonia
• Dalbergia retusa
• nitrogen fixation

Acknowledgments

This work is a contribution of Smart Reforestation® and the Agua Salud Project of the Smithsonian Tropical Research Institute (STRI). Agua Salud is part of ForestGEO and is a collaboration with the Panama Canal Authority (ACP), the Ministry of the Environment (MiAmbiente) of Panama, and other partners. We thank Mario Bailon, Anabel Rivas, Julia Gonzales, Guillermo Fernandez, Johana Balbuena, Miguel Nunes, and our many interns for data collection and processing. Field work was supported by the Smithsonian Institution Grand Challenges Program, the Hoch Family, Stanley Motta, and the Silicon Valley Foundation, with additional support from the Working Land and Seascapes Program of the Smithsonian Institution Conservation Commons.

Disclosure statement

No potential conflict of interest was reported by the author(s).

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Additional information

Funding

This work was supported by the Smithsonian Institution Grand Challenges Program; Silicon Valley Foundation; Stanley Motta; Hoch Family; Working Land and Seascapes Program of the Smithsonian Institution Conservation Commons.