Early and intermediate aged successional study sites are located in the Atlantic lowlands of NE Costa Rica at La Selva Biological Station (Heredia Province) and surrounding areas of premontane wet forest (Holdridge et al. 1975). Study plots are on weathered ultisols on upland residual basalt (Sollins et al., 1994). Annual monitoring of woody vegetation dynamics of trees, saplings, and seedlings in four 1-ha plots was initiated in 1997 (Redondo Brenes et al. 2001, Chazdon et al. 2005, Capers et al. 2005).
Six study sites were abandoned pastures dating from the 1970s and 1980s, with variable densities of remnant trees. Four sites were cleared and prepared for planting and then abandoned or were used for one cycle of cultivation; these have been monitored since 1987. Two 1-ha plots sites are in mature forest. Mean daily temperature in La Selva is 25.8°C with mean annual rainfall of 3,962 mm (Sanford et al. 1994). On average, 80.9 % of annual rainfall occurs during the May–December wet season.
The surrounding landscape matrix consists of selectively logged forest, remnants of mature forest, pasture, and agricultural plantations. Additional chronosequence sites for this region span over 40 yr and include 5 additional 0.25 ha plots (J. Schedlbauer and B. Finegan, unpublished data and 30 0.1 ha sites studied by doctoral student S. Letcher).