Glime, J. M. and Pócs, T. 2018. Tropics: Epiphylls. Chapt. 8-6. In: Glime, J. M. Bryophyte Ecology. Volume 4. Habitat and 8-6-1 Role. Ebooksponsored by Michigan Technological University and the International Association of Bryologists. Last updated 23 July 2020 and available at <http://digitalcommons.mtu.edu/bryophyte-ecology4/>. CHAPTER 8-6 TROPICS: EPIPHYLLS JANICE M. GLIME AND TAMÁS PÓCS TABLE OF CONTENTS Epiphyllous Communities ................................................................................................................................... 8-6-2 Fossil Records ..................................................................................................................................................... 8-6-9 Biomass Contributions ........................................................................................................................................ 8-6-9 Microclimate ....................................................................................................................................................... 8-6-9 Colonization ...................................................................................................................................................... 8-6-13 Succession ......................................................................................................................................................... 8-6-13 Host Preference ................................................................................................................................................. 8-6-16 Growth Structure ............................................................................................................................................... 8-6-18 Bryophyte Adaptations ...................................................................................................................................... 8-6-18 Morphology ................................................................................................................................................ 8-6-19 Water Relations .......................................................................................................................................... 8-6-20 Life Cycles ................................................................................................................................................. 8-6-23 Neoteny ............................................................................................................................................... 8-6-24 Life Strategy Types .................................................................................................................................... 8-6-25 Host Adaptations ............................................................................................................................................... 8-6-25 Drip Tips .................................................................................................................................................... 8-6-25 Leaf Size and Shape ................................................................................................................................... 8-6-26 Leaf Age .................................................................................................................................................... 8-6-26 Leaf Longevity ........................................................................................................................................... 8-6-27 Leaf Chemistry ........................................................................................................................................... 8-6-27 Interactions ........................................................................................................................................................ 8-6-28 Nutrient Exchanges .................................................................................................................................... 8-6-28 Host Leaf Leachates ............................................................................................................................ 8-6-28 Bryophyte Leachates ........................................................................................................................... 8-6-28 Seed Beds ............................................................................................................................................ 8-6-29 Nitrogen Fixation ....................................................................................................................................... 8-6-29 Herbivore Protection .................................................................................................................................. 8-6-30 Micro-organisms ........................................................................................................................................ 8-6-32 Negative Impacts on Leaves ...................................................................................................................... 8-6-33 Light Interference ....................................................................................................................................... 8-6-33 Species Richness ............................................................................................................................................... 8-6-34 Asia ............................................................................................................................................................ 8-6-34 South Pacific Islands .................................................................................................................................. 8-6-39 Africa ......................................................................................................................................................... 8-6-39 Neotropics .................................................................................................................................................. 8-6-40 Central America .................................................................................................................................. 8-6-40 South America .................................................................................................................................... 8-6-41 Bromeliad Basins .............................................................................................................................................. 8-6-43 Fragmented Habitats ......................................................................................................................................... 8-6-45 Sampling Epiphylls ........................................................................................................................................... 8-6-46 Summary ........................................................................................................................................................... 8-6-47 Acknowledgments ............................................................................................................................................. 8-6-47 Literature Cited ................................................................................................................................................. 8-6-47 8-6-2 Chapter 8-6: Tropics: Epiphylls CHAPTER 8-6 TROPICS: EPIPHYLLS JANICE M. GLIME AND TAMÁS PÓCS Figure 1. Epiphyllous Lejeunea floridana and Cololejeunea cardiocarpa. Photo by Scott Zona, with permission. reported, albeit not well-developed, in wet temperate Epiphyllous Communities regions as well: Japan (Schiffner 1929), the Appalachian A unique community occurs in the tropics, especially Mountains, USA (Schuster 1959; Ellis 1971), British in the wet rainforests, the epiphyllous community (Figure Columbia (Vitt et al. 1973), the Caucasus (Pócs 1982b; 1), i.e. those bryophytes, lichens, algae, fungi, and bacteria Vězda 1983), Macaronesia (Sjögren 1975, 1978) and the that live on the leaves of higher plants. Among these, Pyrenees (Vězda & Vivant 1972). bryophytes contribute most of the biomass (Bentley 1987). In equatorial regions, these foliicolous communities A discussion of tropical epiphytes would not be complete occur from sea level to about 3000 m asl, where they without considering these bryophytes that spend their lives become limited by lack of forest substrate. Pócs (1976a, on leaves. 1982a) concluded that the upper limit is determined by the Some of the earliest bryophyte studies in the tropics frequency of night frosts and the degree of oceanity. were on epiphyllous species, typically on trees and shrubs. Optimal conditions, on the other hand, occur in the lower These included studies by Goebel (1888, 1889), Massart montane rainforest belt. In East Africa this occurs at (1898), Busse (1905), Pessin (1922), Richards (1932), ~1500-2000 m. Allorge et al. (1938), and Allorge & Allorge (1939). Later, Luo (1990) noted the need for very moist air in the Winkler (1967, 1970) reported on epiphyllous communities habitats of epiphyllous liverworts. This defines the primary of both upland and lowland rainforests of tropical distribution of epiphyllous liverworts in the tropical or Americas. subtropical regions of IndoMalay, Central and South Foliicolous bryophytes occur predominantly on the America, central Africa, and the Asian-Pacific regions of upper surface of leaves (epiphyllous), but some do occur South Korea