Research Seedling growth responses to phosphorus reflect adult distribution patterns of tropical trees Paul-Camilo Zalamea1, Benjamin L. Turner1, Klaus Winter1, F. Andrew Jones1,2, Carolina Sarmiento1 and James W. Dalling1,3 1Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Republic of Panama; 2Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331-2902, USA; 3Department of Plant Biology, University of Illinois, Urbana, IL 61801, USA Summary Author for correspondence: Soils influence tropical forest composition at regional scales. In Panama, data on tree com- Paul-Camilo Zalamea munities and underlying soils indicate that species frequently show distributional associations Tel: +507 212 8912 to soil phosphorus. To understand how these associations arise, we combined a pot experi- Email:
[email protected] ment to measure seedling responses of 15 pioneer species to phosphorus addition with an Received: 8 February 2016 analysis of the phylogenetic structure of phosphorus associations of the entire tree commu- Accepted: 2 May 2016 nity. Growth responses of pioneers to phosphorus addition revealed a clear tradeoff: species New Phytologist (2016) from high-phosphorus sites grew fastest in the phosphorus-addition treatment, while species doi: 10.1111/nph.14045 from low-phosphorus sites grew fastest in the low-phosphorus treatment. Traits associated with growth performance remain unclear: biomass allocation, phosphatase activity and phos- Key words: phosphatase activity, phorus-use efficiency did not correlate with phosphorus associations; however, phosphatase phosphorus limitation, pioneer trees, plant activity was most strongly down-regulated in response to phosphorus addition in species from communities, plant growth, species high-phosphorus sites. distributions, tropical soil resources.