Document: STE-3-35-34

Host tree specificity of epiphytic bromeliads on trees in tropical experimental plots, La Selva, Costa Rica.

RENTMEESTER, S.* ¹, N.NADKARNI ¹ and J.EWEL ²

The Evergreen State College, Olympia, WA 98502, USA ¹
Institute of Pacific Islands Forestry, Honolulu, HI 96816, USA ²

Abstract:
This study documents host specificity in epiphytic bromeliads in a lowland wet tropical forest. We quantified the relative abundance, community composition, diversity, and spatial distribution of epiphytic bromeliads in monospecific stands. The experimental stands were planted using a replicated block design. We related these measurements to the age (four- and eight-year-old) and species (Cedrela ordorata, Cordia alliodora, and Hyeronima alchorneoides) of the host. Age had the strongest influence on mean density of bromeliads per tree with an order of magnitude between eight-year-old (mean=17.63) and four-year-old (mean=1.42) host. Mean density showed significant differences among the three hosts within eight-year-old (F=226.943, P=0.000) and four-year-old (Chi squared=47.151, P=0.000) trees. Age was also a significant factor for species diversity (F=130.409, P=0.000) with diversity decreasing in the older hosts. Bromeliad diversity depended on host species in both eight-year-old (F=111.013, P=0.00) and four-year-old (F=16.905, P=0.000) hosts. Both mean density of bromeliads per tree and bromeliad size class distribution showed a host-specific vertical shift.

Keywords: epiphyte, bromeliads, host tree specificity, Costa Rica, tropical rainforest

This abstract is being presented at: 10:45 AM in session:
Oral Session #5: Mutualisms.