Effects of climatic variation on the interannual diametric growth of eight dry forest tree species in the northern Pacific coast of Costa Rica

Abstract

The growth of trees in tropical dry forest has a significant relationship with the climate: growth develops in rainy season and in dry season growth stagnates. However, few species have growth studies. Therefore, the study characterized the effects of climatic variation on the diameter growth (Cd) of the eight most important tree species in a tropical dry forest in Costa Rica. Twelve trees were selected per species, in which the Cd was measured between 2015 and 2018, complemented with climatic measurements (temperature, precipitation, relative humidity and light hours) and determination of the density of the wood (Dm). Cd equations were developed with climatic variables and relationships of Dm with Cd were evaluated. The results showed that the annual Cd is 3.04 mm in Albizia niopoides; 2.83 mm in Bursera simaruba, 2.07 mm in Cordia alliodora, 1.92 mm in Cordia panamensis, 0.68 mm in Hymenaea courbaril; 3.82 mm in Luehea speciosa; 1.63 mm in Machaerium biovulatum and 0.30 mm in Handroanthus impetiginosus; a growth phase was found in the rainy season and slight diametric contractions in the dry season. With the significant correlation of Cd with precipitation and annual mean temperature, a positive relationship between Dc and precipitation and a negative relationship between Cd and average temperature, which allowed the development of linear growth prediction equations with R² greater than 0.61 and errors less than 1.00. Finally, relationships between Cd and Dm were determined; as Dm was lower, higher Cd were obtained.