Tree abundance in eight 1-ha tropical forest plots in northeastern Costa Rica from 1997-2017

In 1997, four 1-ha plots were established in secondary forests (12-25 yr since establishment on former pasture) in northeastern Costa Rica, in and around La Selva Research Station. In 2005, four additional plots were established, two in 10-yr old sites and two in old growth sites. The dataset contains information for 155,378 trees. Each year, from 1997-2017 all stems with a diameter of breast height ≥ 5 cm were censused in each site within 100 subplots of 10m x 10m. All but a few individuals were identified to species with confirmed identifications by local experts and vouchers. Life form for each species was also recorded as tree (reaching canopy), midtree (midstory tree), treelet (understory tree), shrub, liana, palm, or understory palm. The specimen-based data set contains data for all trees that were alive (not completely dead) and standing in each annual census, including notes on new recruits or damaged trees. Each tree individual is identified by a unique stem identifiation code and each entry has a unique specimen code. Each tree had a unique numbered tag, nailed into the stem. Locations of diameter measurements were painted on each tree to minimize annual variation and field technians had data from the prior year to confirm information for each tree. These were generally taken at 1.3 m height. In cases where a buttress or stilt root caused a stem irregularity, the measurement point was moved upwards beyond any stem irregularity. The diameter measurement for each specimen reflects each year's measurement point.