This publication presents the 21-year record of fine-litterfall (leaves, reproductive materials, twigs < 1 cm diameter) in the 18 plots of the CARBONO Project in the old-growth tropical rainforest at La Selva Biological Station, Costa Rica.  The CARBONO Project (1997-2018) was a multidisciplinary long-term research program to quantify forest carbon cycling at the landscape scale in the old-growth upland forest. The dataset is complete and has been through extensive qa/qc based on internal checks and readbacks.

To study carbon-cycle processes at the landscape scale, a network of 18 0.5-ha permanent plots was established across the old-growth forest at La Selva, using an unbiased, random-block design based on pre-determined coordinates drawn from the soils and topographic coverages of La Selva’s geographic information system.  This network was designed to sample the upland old-growth forest with replication on each of the three dominant edaphic conditions (younger oxisol alluvial terrace, older oxisol plateau, and older oxisol slope; six plots each).  Biweekly through the period October 1997 – October 2018, fine litterfall was collected from nine paired standing basket-traps and ground traps arrayed across each of the 18 plots.  In the lab, the materials were then separated by category and dried to constant weight.  When a trap was found to be compromised by blockage or trap damage from falling wood or by animals, its contents were discarded and the trap was immediately repaired or replaced.  The plot-level litterfall in each biweekly collection period was based on the actual number of active traps in that collection period. 

A ReadMe file provides detailed documentation.  The only missing values are in blanks in  the comments variable in the data set.