, 153:225 | Cite as

The influence of life form on carbon and nitrogen relationships in tropical rainforest ferns

  • James E. WatkinsJr
  • Philip W. Rundel
  • Catherine L. Cardelús


Tropical ferns are characterized by a high diversity of plant life forms, yet there have been few large-scale studies on the functional ecology of these different forms. We examined epiphytic, hemiepiphytic, and terrestrial ferns, and asked whether there are differences in the mineral nutrition and water relations across different growth forms of a diverse assemblage of species. We measured specific leaf area, leaf nitrogen concentrations, and natural abundance of the stable isotopes δ15N and δ13C of 48 fern species from 36 genera across a wide range of habitats at La Selva Biological Station in Costa Rica. We found that epiphytes were significantly different in all measured variables from hemiepiphytic and terrestrial species, and that terrestrial and soil-rooted hemiepiphytes were indistinguishable in all variables excluding SLW. A multivariate analysis revealed that aspects of N nutrition were the most reliable at separating epiphytic species from other life forms. Our study demonstrates that the natural abundance of both C and N as well as N relations and leaf morphology are useful when segregating different plant life forms, and that the N cycle of epiphytic and terrestrial habitats function independently from each other.


Pteridophytes Epiphyte Hemiepiphyte Nitrogen Carbon 


  1. Bergstrom DM, Tweedie CE (1998) A conceptual model for integrative studies of epiphytes: nitrogen utilisation, a case study. Aust J Bot 46:273–280CrossRefGoogle Scholar
  2. Cardelús C (2007) Vascular epiphyte communities in the inner-crown of Hyeronima alchorneoides and Lecythis ampla at La Selva Biological Station, Costa Rica. Biotropica 39:171–176CrossRefGoogle Scholar
  3. Cardelús C, Colwell RK, Watkins JE Jr (2006) Vascular epiphyte distribution patterns: explaining the mid-elevation richness peak. J Ecol 94:144–156CrossRefGoogle Scholar
  4. Chapin FS (1980) The mineral nutrition of wild plants. Annu Rev Ecol Syst 11:233–260Google Scholar
  5. Evans RD (2001) Physiological mechanisms influencing plant nitrogen isotope composition. Trends Plant Sci 6:121–126PubMedCrossRefGoogle Scholar
  6. Freiberg M, Turton SM (2007) Importance of drought on the distribution of the birds nest fern, Asplenium nidus, in the canopy of a lowland tropical rainforest in north-eastern Australia. Aust Ecol 32:70–76CrossRefGoogle Scholar
  7. Frazer GW, Canham CD, Sallaway P, Marinakis D (1999) Gap light analyzer. Simon Fraser University, Burnaby, BC, Canada/Institute for Ecosystem Studies, Millbrook, NYGoogle Scholar
  8. Hietz P, Briones O (1998) Correlation between water relations and within-canopy distribution of epiphytic ferns in a Mexican cloud forest. Oecologia 114:305–316CrossRefGoogle Scholar
  9. Hietz P, Wanek W (2003) Size-dependent variation of carbon and nitrogen isotope abundances in epiphytic bromeliads. Plant Biol 5:137–142Google Scholar
  10. Hietz P, Wanek W, Popp M (1999) Stable isotopic composition of carbon and nitrogen and nitrogen content in vascular epiphytes along an altitudinal transect. Plant Cell Environ 22:1435–1443CrossRefGoogle Scholar
  11. Hietz P, Wanek W, Wania R, Nadkarni NM (2002) Nitrogen-15 natural abundance in a montane cloud forest canopy as an indicator of nitrogen cycling and epiphyte nutrition. Oecologia 131:350–355CrossRefGoogle Scholar
  12. Kluge M, Brulfert J, Rauh W, Ravelomanana D, Ziegler H (1995) Ecophysiological studies on the vegetation of Madagascar: a delta C-13 and delta D survey for incidence of Crassulacean acid metabolism (CAM) among orchids from montane forests and succulents from the xerophytic thorn-bush. Isot Environ Health Stud 31:191–210Google Scholar
  13. Marks CO, Lechowicz MJ (2006) Alternative designs and the evolution of functional diversity. Am Nat 167:55–66PubMedCrossRefGoogle Scholar
  14. McDade LA, Bawa KS, Hespenheide HA, Hartshorn GS (eds)(1994) La Selva: Ecology and natural history of a neotropical rain forest. Chicago University Press, Chicago, ILGoogle Scholar
  15. Nelson JA, Barnes PW, Archer S (2002) Leaf demography and growth responses to altered resource availability inwoody plants of contrasting leaf habit in a subtropical savanna. Plant Ecol 160:193–205CrossRefGoogle Scholar
  16. Putz FE, Holbrook NM (1989) Strangler fig rooting habits and nutrient relations in the llanos of Venezuela. Am J Bot 76:781–788Google Scholar
  17. Reich P (1991) From tropics to tundra: global convergence in plant functioning. Proc Natl Acad Sci USA 94:13730–13734CrossRefGoogle Scholar
  18. Richards PW (2004) The tropical rain forest, 2nd edn. Cambridge University Press, CambridgeGoogle Scholar
  19. Reich PB, Ellsworth DS, Walters MB, Vose JM, Gresham C, Volin JC, Bowman WD (1999) Generality of leaf trait relationships: a test across six biomes. Ecology 80:1955–1969Google Scholar
  20. Reich A, Ewel JJ, Nadkarni NM, Dawson T, Evans RD (2003) Nitrogen isotope ratios shift with plant size in tropical bromeliads. Oecologia 137:587–590PubMedCrossRefGoogle Scholar
  21. Rundel PW, Rundel JA, Ziegler H, Stichler W (1979) Carbon isotope ratios of central Mexican crassulaceae in natural and greenhouse environments. Oecologia 38:45–50CrossRefGoogle Scholar
  22. Rundel PW, Stichler W, Zander RH, Ziegler H (1980) Carbon and hydrogen isotope ratios of bryophytes from arid and humid regions. Oecologia 44:91–94CrossRefGoogle Scholar
  23. SAS Institute (2005) User’s guide for JMP v.5.1. SAS Institute, Cary, NCGoogle Scholar
  24. Smith TM, Shugart HH, Woodward FI (eds) (1997) Plant functional types: their relevance to ecosystem properties and global change. Cambridge University, CambridgeGoogle Scholar
  25. Stewart GR, Schmidt S, Handley LL, Turnbull MH, Erskine PD, Joly CA (1995a) N-15 natural abundance of vascular rainforest epiphytes implications for nitrogen source and acquisition. Plant Cell Environ 18:85–90CrossRefGoogle Scholar
  26. Stewart GR, Turnbull MH, Schmidt S, Erskine PD (1995b) C13 Natural abundance in plant communities along a rainfall gradient: a biological indicator of water availability. Aust J Plant Phys 22:51–55CrossRefGoogle Scholar
  27. Tuomisto H, Poulsen AD, Ruokolainen K, Moran RC, Quintana C, Celi J, Canas G (2003) Linking floristic patterns with soil heterogeneity and satellite imagery in Ecuadorian Amazonia. Ecol Appl 13:352–371Google Scholar
  28. Vance ED, Nadkarni NM (1990) Microbial biomass and activity in canopy organic matter and the forest floor of a tropical cloud forest. Soil Biol Biochem 22:677–684CrossRefGoogle Scholar
  29. Wanek W, Arndt SK, Huber W, Popp M (2002) Nitrogen nutrition during ontogeny of hemiepiphytic Clusia species. Funct Plant Biol 29:733–740CrossRefGoogle Scholar
  30. Wania R, Hietz P, Wanek W (2002) Natural 15N abundance of epiphytes depends on the position within the forest canopy: source signals and isotope fractionation. Plant Cell Environ 25:581–589CrossRefGoogle Scholar
  31. Watkins JE Jr (2006) Comparative functional ecology of tropical ferns. Ph.D. dissertation. University of Florida, Gainesville, FLGoogle Scholar
  32. Watkins JE Jr, Cardelús CL, Colwell RK, Moran RC (2006) Species richness and distribution of ferns along an elevational gradient in Costa Rica. Am J Bot 93:73–83Google Scholar
  33. Watkins JE Jr, Mack MC, Mulkey SS (2007) Gametophyte ecology and demography of epiphytic and terrestrial tropical ferns. Am J Bot 94:701–708Google Scholar
  34. Wright IJ, Westoby M, Reich PB (2002) Convergence towards higher leaf mass per area in dry and nutrient-poor habitats has different consequences for leaf life span. J Ecol 90:534–543CrossRefGoogle Scholar
  35. Zotz G, Hietz P, Schmidt G (2001) Small plants, large plants: the importance of plant size for the physiological ecology of vascular epiphytes. J Exp Bot 52:2051–2056PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • James E. WatkinsJr
    • 1
  • Philip W. Rundel
    • 2
  • Catherine L. Cardelús
    • 3
  1. 1.Arnold ArboretumHarvard UniversityCambridgeUSA
  2. 2.Department of Ecology and Evolutionary Biology and Center for Embedded Networked SensingUniversity of CaliforniaLos AngelesUSA
  3. 3.Department of BotanyUniversity of FloridaGainesvilleUSA

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