Fortuna Forest Reserve, Panama: Interacting Effects of Climate and Soils on the Biota of a Wet Premontane Tropical Forest

The Fortuna Forest Reserve and adjacent upland areas of the Palo Seco Reserve in western Panama support some of the most extensively studied lower and premontane tropical forests in the world. The forests of Fortuna are among the most diverse in Central America and are therefore of exceptional significance for the preservation of regional biodiversity. This volume brings together more than 50 years of research on the climate, geology, soils, and major plant groups of Fortuna. Spanning the Continental Divide at around 1,000 m above sea level, some parts of the reserve receive more than 6,000 mm of annual rainfall, although there is considerable variation in cloud cover and seasonality. Soil fertility also varies markedly, reflecting the complex regional volcanic geology. The resulting gradients of climate and fertility across the reserve shape the composition, structure, and diversity of plant communities. A network of 12 one-hectare plots at Fortuna contains more than 400 species of trees greater than 5 cm diameter at breast height and reveals extensive compositional turnover across the reserve. One tree species, <i>Oreomunnea mexicana</i>, forms monodominant stands in otherwise species-rich forests, while forests on extremely infertile soils are dominated by the canopy palm <i>Colpothrinax aphanopetala</i> and include the tropical conifer <i>Podocarpus oleifolius</i>. There are also almost 400 species of bryophytes, almost 300 species of ferns and lycophytes, 31 species of palms, 80 species of bromeliads, and more than 200 species of orchids. Many species of ectomycorrhizal fungi identified from fruiting bodies are new to science. Overall, results from Fortuna highlight the remarkable diversity of plants that occur in montane forests and the extent to which their communities are structured by gradients of climate and soil fertility. The chapters in this volume provide a foundation for further research and exploration in this fascinating region.