Dr. Catherine Potvin

Background and Objectives

The Sardinilla Project (SP) is an international and inter-institutional research facility administered by the Smithsonian Tropical Research Institute (STRI) and located at Sardinilla (9o19’30”N, 79o38’00”W) in the Buena Vista region of Central Panama some 20 km bird flight from the island of Barro Colorado.

The long-term objective of the Sardinilla Project is to understand the complex links between carbon , nitrogen and water cycling and biodiversity in tropical environments. It attempts to rectify the dearth of knowledge of the role of tropical ecosystems in the global C cycle. Our research agenda over the next 15 years centers on two central questions:

How does the transition in land use from grazed pasture to tree plantation affect ecosystem fluxes of C?
How does community richness and identity of tree species affect C accumulation and cycling?
The Sardinilla Project is a collaboration bringing together scientists from Panama (H. Barrios), Canada (T. Handa, M. Loreau, C. Potvin, C. Messier, T. Moore ), Germany (Y. Oelmann, M. Scherer-Lorenzen, N. Kunert), Switzerland (W. Wilcke) and New Zealand (L. Schwendenmann). The two leading institutions are STRI (Panama) and McGill University (Canada). Capital investment to establish the flux component was through a grant from the Ministère de la recherche, de la science et de la technologie (Quebec) to McGill University while the biodiversity plantation was established with a NSERC (Canada) discovery grant to Potvin.

The global carbon budget indicates that the current burning of tropical forests exceeds re-growth and is releasing around 1.6 +/- 1 Gt Cyr-1 into the atmosphere. With a ratio of deforestation to reforestation area for the tropical world around 10.3 in 1980, land use is clearly at the center of understanding global change. Although there is strong evidence that tropical deforestation has contributed to an increase in atmospheric CO₂ , it is not known how effective the conversion of pasture back into forests would be in off-setting the CO₂.

In addition to providing estimates of the C sequestration potential of tropical plantations, the use of native tree species in our plantation will provide data on the importance of biodiversity for C cycling. A major research effort launched by ecologists in the last decade is the pursuit of understanding the relationship between species diversity and ecosystem function.

On theoretical grounds, positive and linear, positive and non-linear or no relationship between these variables have been postulated. Overall, the relationship between biodiversity, ecosystem function and stability appears to depend upon the system under study, the number of trophic levels analyzed and the ecosystem parameters that are measured. Because the bulk of the relevant experimental work has been done with herbaceous species mostly in temperate regions, there is a need to study structurally complex ecosystems.

The Sardinilla Project is part of Treedivnet a global network of nine similar biodiversity tree plantations including boreal, temperate and tropical forest experiments.

Related Publications:

• Wolf, S., Eugster, W., Potvin, C., Turner, B. and Buchmann, N. 2011. Carbon sequestration potential of tropical pasture compared with afforestation in Panama. Global Change Biology 17: 2763-2780.
• Ruiz-Jaen, M.C. and Potvin, C. 2011. Can we predict carbon stocks in tropical ecosystems from tree diversity? Comparing species and functional diversity ina plantation and natural forest. New Phytologist 189: 978-987.
• Povin, C., Mancilla, L., Buchmann, N., Monteza, J., Moore, T., Murphy, M., Oelmann, Y., Scherer-Lorenzen, M., Turner, B. L., Wilcke, W., Zeugin, F. and Wolf, S. 2011. An ecosystem approach to biodiversity effects: Carbon pools in a tropical tree plantation. Forest Ecology and Management 261: 1614-1624.
• Plath, M., Mody, K., Potvin, C. and Dorn, S. 2011. Establishment of native tropical timber trees in monoculture and mixed-species plantations: Small-scale effects on tree performance and insect herbivory. Forest Ecology and Management 261: 741-750.
• Plath, M., Mody, K., Potvin, C. and Dorn, S. 2011. Do multipurpose companion trees affect high value timber trees in a silvopastoral plantation system? Agroforest System 81: 79-92.
• Wolf, S., Eugster, W., Potvin, C. and Buchmann, N. 2011. Strong seasonal variations in net ecosystem CO₂ exchange of a tropical pasture and afforestation in Panama. Agricultural and Forest Meteorology 151: 1139-1151.
• Oelmann, Y., Potvin, C., Mark, T., Werther, L., Tapernon, S. and Wilcke, W. 2010. Tree mixtures effects on aboveground nutrient pools of trees in an experimental plantation in Panama. Plant Soil 326: 199-212.
• Zeugin, F., Potvin, C., Jansa, J. and Scherer-Lorenzen, M. 2010. Is tree diversity an important driver for phosphorus and nitrogen acquisition of a young tropical planatation? Forest Ecology and Management 260: 1424-1433.
• Potvin, C., Mancilla, L., Buchmann, N., Monteza, J., Moore, T., Murphy, M., Oelmann, Y., Scherer-Lorenzen, M., Turner, B. L., Wilcke, W., Zeugin, F. and Wolf, S. 2011. An ecosystem approach to biodiversity effects: carbon pools in a tropical tree plantation. Forest Ecology and Management 261: 1614-1624.