All trees at least 1 cm diameter at breast height were censused in three sites in Panama. The Barro Colorado plot is 50 hectares in area and was fully censused on eight occasions between 1982 and 2015. The Sherman plot is 5.96 hectares and was fully censuses four times between 1996 and 2009. The Cocoli plot is 4 hectares and was censused three times between 1994 and 1999. The three accompanying tables give the population size of living individuals of all species in every census at the three sites. 

Every individual was mapped, tagged, and identified if the diameter at 1.3 m above the ground was at least 1 cm. Individuals with multiple stems from one root base were counted as single trees. Every tree was identified with reference to herbarium specimens and published flora (especially T. Croat's Flora of Barro Colorado Island [Stanford, 1978]). Some trees were assigned into distinct morphotypes but could not be fully identified, and a small number of individuals were never identified. Methods are described in detail in Condit, R. [1998. Tropical Forest Census Plots: Methods and Results from Barro Colorado Island, Panama and a Comparison with Other Plots. Springer-Verlag, Berlin.]

Species names are current as of 2017. Two papers, Condit et al. (1996, 2004), list all species and their abundances in early censuses. Many tree species names have been changed since 1982, and a separate data archive (Condit et al. 2017) provides all past names, allowing the tables in the early papers to be linked to the tables here. Because we continually correct the data, exact counts reported in the early papers will not necessarily match those shown now.

In each plot, several taxa are flagged with asterisks. These are cases where the group of trees so named does not represent a single consistent species through time. As identifications evolved, two of the taxa were divided into two species. At that time, any trees that had already died could not be identified using the updated criteria. The counts of these marked species thus cannot be interpreted as changing abundance through time. There were also a number of individuals that were never identified before they died, and the unidentified category is thus flagged with an asterisk.

Species labeled as sp. and lacking a taxonomic authority were morphospecies. They were trees assigned distinct categories based on leaf, bark, flower, or fruit form but never identified. Several of these morphospecies from the 1982 were finally identified later, but several remain and are in the tables. Their counts represent changing abundance through time of individual species; we just do not have a Latin name assigned.

All other taxa, those not flagged with asterisks, represent single, consistently-identified tree species. Their counts represent change in abundance through time. To standardize a density per unit area, each count must be divided by the size of the plot: 50 ha at Barro Colorado, 4 ha at Cocoli, and 5.96 ha at Sherman.

Citations

Condit, R., Hubbell, S. P., and Foster, R. B. 1996. Changes in tree species abundance in a neotropical forest: impact of climate change. Journal of Tropical Ecology 12:231–256. 

Condit, R., Aguilar, S., Hernandez, A., Pérez, R., Lao, S., Angehr, G., Hubbell, S., and Foster, R. 2004. Tropical forest dynamics across a rainfall gradient and the impact of an El Niño dry season. Journal of Tropical Ecology 20:51–72.

R. Condit, S. Aguilar, R. Pérez. S. Lao, S. P. Hubbell, R. B. Foster. 2017. BCI 50-ha Plot Taxonomy as of 2017. DOI https://doi.org/10.25570/stri/10088/32990.