Zotz & Andrade 1998 (Article) Guzmania, Tillandsia

Water relations of two co-occurring epiphytic bromeliads

Author(s):—G. Zotz & J.L. Andrade

Publication:—Journal of Plant Physiology 152: 545-554. (1998)

Abstract:—The water relations of the co-occurring epiphytic bromeliads, Guzmania monostachya and Tillandsia fasculata, were studied in situ in the lowland tropical forest of Barro Colorado Island, Panama. Particular attention was paid to differences in the water relations of smaller and larger plants. Both species showed moderate, but significant seasonal changes in leaf water status and CAM-activity, measured as nocturnal acidification. When water was withheld from plants, 24-h whole plant water loss decreased to a minimum after 4-5 days. There were no significant interspecific or size-related differences in area-based transpiration rates. Due to a lower ratio of plant leaf area to plant water content (LAlPWC), similar area-based transpiration rates resulted in lower relative water losses in T. fasculata. Smaller plants suffered significantly higher relative water losses in G. monostachya, but not in T. fasculata. The observed differences in the water relations of smaller individuals may be responsible for the differences in the spatial distributionin host trees.

Keywords:—Tillandsia, Guzmania, bromeliads, epiphytes, water relations, crassulacean acid metabolism, Barro Colorado Island.