Diversidad y estructura horizontal en los bosques tropicales del Corredor Biológico de Osa, Costa Rica

Abstract

Palabras clave: bosque primario, bosque secundario, distribución diamétrica, área basal, árboles, riqueza de especies, Corredor Biológico Osa, Costa Rica.which is not as effective. The distribution of species and number of trees by diameter class took the form of inverted J, where the reserve of trees and species in the first classes ensure the balance of forests. The main difference in the distribution of basal area by diameter class is given in the last classes (> 55 cm), where forests had the highest values, which are concentrated in a few species and large trees.

Spatially robust estimates of biological nitrogen (N) fixation imply substantial human alteration of the tropical N cycle

“…We measured BNF in 12 0.5-ha plots (50 × 100 m) on the Osa Peninsula, Costa Rica near the Piro Biological Station (8°24′ N, 83°20′ W; 87 m above sea level) (56). SI Methods, sections 1 and 2 provide additional site description.…”

Understory and small trees contribute importantly to stemflow of a lower montane cloud forest

“…Likewise, 6,386 individuals >1 m were found in Ecuador (Grubb, Lloyd, Pennington, & Whitmore, ), 7,261 individuals ha −1 > 1‐m height in a humid tropical forest in Costa Rica (Guariguata et al, ), 11,772 individuals ha −1 > 0.5 m in a premontane tropical rain forest in Costa Rica (Di Stéfano & Hurtado, ), and 11,217 individuals ha −1 > 1 m in a lowland tropical rainforest in Venezuela (Jordan, ). Hence, even though in primary and secondary forests, the density of individuals <10‐cm DBH is much higher than individuals >10‐cm DBH (Grubb et al, ; Guariguata et al, ; Mendonça et al, ; Morales‐Salazar et al, ), few Sf studies have included small trees and shrubs (Appendix S1), suggesting that Sf a of tropical forests may have been systematically underestimated.…”

“…A potential problem of Sf-P and Sf-M methods is that they use average Sf y values, calculated from a sample of trees of different sizes, each assigned an equal weight (Aboal et al, 1999;Hanchi & Rapp, 1997). However, because the diametric distribution of trees in natural forests typically follows a negative exponential distribution, with the highest number of individuals in the smallest DBH classes (Guariguata, Chazdon, Denslow, Dupuy, & Anderson, 1997;Mendonça et al, 2010;Morales-Salazar et al, 2012), the smaller individuals, having usually lower Sf y , may become underrepresented in the mean Sf y , possibly leading to an overestimation of Sf a (Aboal et al, 1999). The average DBH of the trees sampled for Sf was 3.9 cm and that of individuals in S h>2 was 2.5 cm.…”

“…Hence, even though in primary and secondary forests, the density of individuals <10-cm DBH is much higher than individuals >10-cm DBH (Grubb et al, 1963;Guariguata et al, 1997;Mendonça et al, 2010;Morales-Salazar et al, 2012), few Sf studies have included small trees and shrubs (Appendix S1), suggesting that Sf a of tropical forests may have been systematically underestimated.…”

Combustibles forestales superficiales y riesgo de incendio en dos estadios de sucesión secundaria y bosques primarios en el Parque Nacional Palo Verde, Costa Rica

“…En las clases posteriores, de 40 -50 hasta 80 -90 cm se presentó una disminución del área basal con un aumento en las últimas dos categorías diamétricas las cuales corresponden a los diámetros más grandes, comportamiento también presente para el bosque de mayor de 30 años y el de 10-25 años. Morales-Salazar et al (2012), Zamora (2010) y Louman, Quirós y Nilsson (2001) encontraron patrones de distribución de área basal y volumen por clase diamétrica (dap > 10 cm) similares a los del presente estudio.…”