Effect of Topography on the Pattern of Trees in Tabonuco (Dacryodes excelsa) Dominated Rain Forest of Puerto Rico

Biotropica ◽  
1992 ◽  
Vol 24 (1) ◽  
pp. 31 ◽  
Author(s):  
Khadga Basnet
1993 ◽  
Vol 9 (2) ◽  
pp. 231-240 ◽  
Author(s):  
Luis E. Migenis ◽  
James D. Ackerman

ABSTRACTOrchid diversity, distribution and host specificity were examined in a tropical watershed in the Luquillo Experimental Forest of Puerto Rico. Eleven orchid species occur in the area. The low diversity is attributed to island isolation and large-scale hurricane disturbances. Pleurothallis ruscifolia and Maxillaria coccinea were by far the most abundant species in the area and occurred on the largest number of host species and host zones. None of the orchids were host specific or host zone specialists although preferences for hosts and vertical host zones were encountered.Only 8.2% of the 426 trees and shrubs and 24.4% of the 45 species surveyed were orchid phorophytes (= hosts). Examination of host distribution by diameter at breast height (DBH) showed that 80.5% were greater than 16 cm DBH. Orchid species in the area tend to occur on rough bark hosts, but their preferences are not statistically significant. Guarea guidonia (Meliaceae) and Dacryodes excelsa (Burseraceae) are the two most important orchid hosts in our study site comprising 62.9% of all host trees. Careful management of these two tree species is suggested, since these species may be crucial to the maintenance of orchid abundance and diversity in the area.


2000 ◽  
Vol 36 (8) ◽  
pp. 2183-2196 ◽  
Author(s):  
J. Schellekens ◽  
L. A. Bruijnzeel ◽  
F. N. Scatena ◽  
N. J. Bink ◽  
F. Holwerda

1992 ◽  
Vol 8 (01) ◽  
pp. 47-55 ◽  
Author(s):  
Khadga Basnet ◽  
Gene E. Likens ◽  
F. N. Scatena ◽  
Ariel E. Lugo

ABSTRACTHurricane Hugo of September 1989 caused severe damage to the rain forest in the north-rust corner of Puerto Rico. We assessed the severity of damage distributed in space, species, and size-classes of trees in the Bisley Watersheds of the Luquillo Experimental Forest. We analyzed pie- and post-hurricane data for vegetation from transects established in 1987 and 1988. The severity of damage was significantly greater in valleys than on ridges and slopes. All the species exceptDacryodes excelsa, Sloanea berteriana, andGuarea guidoniashowed 100% severe damage. Large trees (> 70 cm DBH) were highly susceptible to hurricane damage, but there was no clear pattern in the small size-classes.D. excelsa(tabonuco) was the most resistant to damage by the hurricane. Tabonuco which has extensive root-grafts and root anchorage to bedrock and subsurficial rocks, apparently can survive frequent hurricanes and continue as a dominant species in this montane tropical rain forest. The high frequency of hurricanes, which can override other ecological and topographic factors, may largely determine the overall spatial pattern of species in this rain forest.


Sign in / Sign up

Export Citation Format

Share Document