Tree inventories and plant functional traits in coffee agroforestry systems of Hojancha - Costa Rica

This study was conducted in the Cantón of Hojancha in the Peninsula de Nicoya in Costa Rica. In the study area, 80 coffee plots belonging to 47 producers (located in the tropical forest between 500 and 800 m.s.n.m.) were surveyed. At each plot a transect 20 m x 50m (1000m2) was used to carry tree inventory. All trees with diameter at breast height (dbh)>10 cm were listed, as well as diameter and maximum height was registered. A total of 2424 individuals corresponding to 80 species were inventoried. Wood density (mg mm-3) and Leaf resistance to tearing (N mm-1) were measured in each plot with species that accounted for 80% of the abundance of the individuals present in the plot. Leaf resistance to tearing was measured with a tearing apparatus (as indicated in (Pérez-Harguindeguy et al. 2013). One leave was selected from 2 trees in each plot (whenever possible) and in this leave a segment 5mm x 3cm was cut (whenever possible, in small leaves segments were smaller). The segment was used in the tearing apparatus to measure the force required to tear it apart. The data presented in the database is the average value for 2 individuals of each species selected in each plot (311 entries). For wood density one tree was selected in each plot and a tree core was extracted using an increment borer. A total of 306 trees were measured. Tree samples were stored in plastic containers and then dried in an air oven until constant weight. Volume and dry weight from core samples were used to calculate stem density. Leaf, flower and fruit phenology was derived from interviews to farmers, whereby farmers were asked in which months a species had leaves, flowers or fruits. Farmers were asked only for species that were present in their farms, and that they knew well. Pérez-Harguindeguy, N., S. Díaz, E. Garnier, S. Lavorel, H. Poorter, P. Jaureguiberry, et al. 2013. New handbook for standardised measurement of plant functional traits worldwide. Australian Journal of Botany 61:167-234.