How organisms reach and colonize bromeliads: a field experimental test of two of Picado’s hypotheses, and the effect of tree age and cardinal distribution on bromeliads in Cartago, Costa Rica
Artículo académicoIntervalo de fecha/hora
Numerous studies have been conducted on the biodiversity of organisms that inhabit bromeliad water tanks. However, little is known about how organisms reach these tanks (also called “phytotelmata”). Two other aspects of bromeliad ecology, the effect of tree age and the cardinal distribution of bromeliads in canopies are slightly better known, but still little research has been done on these subjects for Central American bromeliads. To improve understanding of these subjects, we studied bromeliad ecology in Pejibaye de Jiménez, Cartago, Costa Rica. To avoid destroying natural phytotelmata, we built 150 artificial bromeliads with plastic cups to test Picado’s hypotheses that phytotelmata are colonized via rain and debris. We set them in the field in February 2012 and collected macroinvertebrates from them after seven weeks. We also measured bromeliad leaf length and trunk diameters in 100 Gliricidia sepium trees and counted bromeliads in the four cardinal directions of 60 trees. In agreement with Picado’s hypotheses, the bromeliads that did not receive rainwater had 2,9 times less invertebrates than the control, and the bromeliads that did not receive debris had 3,4 times less invertebrates than the control. Larger trees had more and larger bromeliads growing on them, possibly because they were older and had more structural complexity. Mean number of bromeliads was lower in the west side of canopies, the side that receives less sunlight. These findings not only address Picado’s hypotheses in the centenary of their publication, but also are potentially useful for conservation of bromeliads and the complex microecosystems that they house.
