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VOLUME NUMBER AMERICAN FERN JOURNAL: 60 83 2 (1993) Montane Ferns Formation Tropical Plantlet in A Preliminary Investigation Suzanne Kofiur Department of Biology, Florida International University, Miami, FI^ 33199; FL Tropical Garden, Miami, Faircliild Mary Ann Lee B. John's River Water Management District, Palatka, FL 32178 St. Ferns exhibit a variety of reproductive mechanisms. Sexual reproduction and gameto- phytic apomixis occur via spores, which are dispersed and germinate to form gameto- Many new phytcs. ferns also reproduce vegetatively, producing ramets through rhizoma- tous growth, fragmentation and reestablishment, and the formation of plantlets. These com- ramets arc genetically identical to the parent sporophyte and are morphologically known plex prior to separation from the parent sporophyte. Genera produce viviparous to on plantlets sporophyte fronds include Adiantum, Asplenium, Camptosorus, Cystopteris, & Diplazium, Tectaria, Woodwardia (Page 1979); plants that grow in sheltered habitats in moist forests are the most likely to produce plantlets. Page (1979) notes that vivipary is common we mid-mountain compare two The in forests; in study such objec- forests. tliis tives of our study were to survey the incidence of plantlet production fcms of two trop- in montane ical forests in Costa Rica, and to detennine plantlet production more com- if is mon in the higher, wetter forest than lower, dryer one. tlie Meiiiods We Mo compared two sites in the vicinity of the Wood - Premontane/Lower Montane Forest Transition (Holdridge, 1967) and lower (1460 is m) 1500 and dryer than Nuboso Woods - the Trail (1520 1560m), which are classified as Lower Montane We m Forest "Cloud (true Forest"). sampled 3x3 each four plots in for- recording each fem est, for individual sporophyte encountered: reproductive species, sta- number of and pnmhvtPQ^ tus, fronds, cover (area for tenestrial ^^^ ferns, vertical hc'^^^^ Juveniles were not included. We defined the various measures of frequency and abundance Density as follows: (D) = number the of = individuals per area sampled; (RD) relative density density of the species number of which plots in the species occurred divided by number the of sampled total plots frequency (RF) = frequency of the species divided by F of tlie total the value RD species times 100; and importance = sum RF We (I) the of and divided by 2. ed these for each species each at site. Fieldwork was done May in 1988. Voucher specimens were determined the at Museo urn of the Nacional de Costa Rica by Mike Grayum and Suzanne Ko] remain in Koptur's collection FIU in the herbarium. Results We encountered 32 in total species species make & KOPTUR PLANTLET FORMATION LEE: 61 Table Fern species in lower montane wet forest, Campbell's Woods; Relative density (RD). relative frequency 1. importance and reproduction (RF), (R). (I), RD R RF Species I none Asplenium auritum Sw. 2.63 4.55 3.59 barbaense Hi eron 10.52 4.55 7.53 spores A. A. gomezianum Lellinger 5.27 4.55 4.91 spores A. pteropus Kaulf. 2.63 4.55 3.59 spores none Blechnum (Liebm.) C.Qir. 2.63 4.55 3.59 erisifonne none Campyloneurum sphetiodes (Kunze ex. Kl. Fee) 5.27 4.55 4.91 Ctenitis atrogrisea (C. Chr.) Ching 2.63 4.55 3.59 spores hemsleyana (Baker) Copeland 2.63 4.55 3.59 spores C. C. subincisa (Willd.) Ching 2.63 4.55 3.59 spores DipUizium urticifolium Qirist 2.63 4.55 3.59 planllets spores Lomariopsis (Maxon) 15.79 18.18 16.98 latiuscula Holtt. & none Polyhotrya osimnidacea H. B. ex Willd. 10.52 4.55 7.53 none 4.55 3.59 anceps 2.63 Selaginella Presl. spores 4.55 3.59 Thelypteris hatchii A. R. Smith 2.63 spores 9.09 8.49 Trichonuines radicans Sw. 7.89 spores Sw. 21.04 13.64 17.34 reptans T. Table Fern species lower montane rain forest, Nuboso Woods: Relative density, relative frequency, impor- 2. in and tance, reproduction. R RD RF I Species spores 2.22 1.64 Asplenium cirrhatum L. C. Rich ex Willd 1.06 spores 2.22 1.64 gomezianum 1.06 A. Lellinger both 4.44 3.82 harpeodes Kunze 3.19 A. both 8.13 6.67 9.58 nmxonii A. Lellinger spores 11.85 6.67 17.02 A. pteropus Kaulf. both 2.18 2.22 Hennipman 2.13 Bolbitis oligarchia (Baker) spores 5.47 6.67 Camplyloneunim sphenodes (Kunze) Fee 4.26 spores 1.64 2.22 Ching 1.06 Ctenitis atrogrisea (C. Qir.) spores 5.47 6.67 4.26 hemsleyana Copeland C. (Baker) none 2.22 1.64 Cyatheafulva Fee 1.06 (Mart. Gal.) &. spores 1.64 2.22 1.06 Diplazium cristatum (Desr.) Alston plantlets 1.64 2.22 D. lehmanii Hieron 1.06 both 2.71 2.22 D. multigemmatum 3.19 Lellinger plantlets 11.85 6.67 17.02 D. urticifolium Christ none 3.29 4.44 D. werckleanum 2.13 Qirist spore 1.64 s 2.22 Elaphoglossum 1.06 exiinium (Mett.) Qirist spores 1.64 2.22 Sm. 1.06 E. latifolium (Sw.) J. spores 1.64 2.22 Grammitis 1.06 Proctor taxifolia (L.) spores 1.64 2.22 Hymenophyllum consanguineum Morton 1.06 spores 8.17 8.89 7.45 Lomariopsis (Maxon) latiuscula Holtt. spores 1.64 2.22 Pccluma 1.06 pectinata Proctor (L.) spores 3.82 4.44 Morton 3.19 Peltapteris peltata (Swartz) none 1.64 2.22 Polypodium 1.06 fraxinifoUum Jacq. spores 3.82 4.44 3.19 Thelypteris hatchii A. R. Siiiit]] spores 9.77 8.89 10.64 Trichonuines reptans Sw. VOLUME NUMBER AMERICAN FERN JOURNAL: 83 2 (1993) 62 L Fig. Planllet production from Asplmium leaf tips in imxonii. The plantlet not shaded drawing. Tlie is in tlie bar scale 2 cm. is maxonii: in both species lehman gemnatum, and D. urticifolium) frond at the intersection of a major vein and Uic midrib, the planUct developing roots, first then leaves that curve around to the adaxial The leaf surface (Fig. unusual Bolhitis oli- 2). garchia has dimorphic fronds and trifoliate leaves, and formed middle plantlels are in the of the on 3 leaflets the adaxial surface of the trophophylls (leaves not specialized for We spore production) (Fig. 3). also observed plantlets on Lotmriopsis but not latiuscula, on any individuals our in study plots. We Campbells Woods (Table Ten species were found 1). sporing Diplazntm species, urticifolium, had Ume plantlets at the of our census. The species the greater imporLince values reproduced bv snores alonp KOPTUR & PLANTLET FORMATION LEE: 63 C Table 3 - Comparative importance of fern species occurring at both sites. = importance, = Camphcll's I Woods 1(C) I(N) Reproduction Asplenium gomezianum 4.91 1.64 spores pteropus 3.59 11.85 .spores A. Campyloneurum sphenodes 4.91 5.47 spores Ctenitis atrogrisea 3.59 1.64 spores hemsleyana 3.59 5.47 spores C. Diplazium 3.59 11.85 plantlels urticifolium 8.17 spores Lomariopsis 16.98 latiuscula 3.82 spores 3.59 Thelypteris hatchii 9.77 spores Trichonuines reptans 17.34 20 Of (Nuboso), 25 species 15 genera found in the higher elevation rain forest site in Four species were making spores, and 6 species were making plantlets (Table 2). species Of had both snores and plantlets, 2 species had plantlets only. the species wiUi the greater ifoli planUet 1cm was Only one species ot Nine species occurred in plots at both sites (Table 3). found bearing plantlets in both forests (Diplazium urticifolium). There were compared Table The two are in 4. properties of the fern species at the sites producing more higher elevation and a larger proportion of species species at the site, A Nuboso were from .sporulat- plandets (24% 6%). larger proportion of ferns the site vs. A ing (80% 63%), and 16% had both plantlets and spores. larger proportion of ferns in vs. Woods (31% 12%). Campbells were non-reproductive vs. For dramatic (Table comparisons done on an individual plant basis are less 5). Similar = significant .024); planUet production on individuals, Fisher's exact test (2-tailed) is (p 3% Campb only Woods versus in produce plantlets, Woods 45% Woods Woods Campbells versus in Uny developing frond of Prom Diphrjum left to right: Fig. 2. Plantlet production on frond.s in urticifolium. iporophyte planllet on drawing. J\^c bar shaded in the are not Ume Tlie plantlets ravaged by and herbivores; plantlet ro<^led in .soil. cm scale 2 is VOLUME NUMBER AMERICAN FERN JOURNAL: 64 83 2 (1993) Fig. Planllet proJuction 3. in ccnier of frond of Bolhitis oUsavchia. Tl,e pLintlet is not shaded in tlie drawing Tlie bar scale 2 cm. is KOPTUR & PLANTLET FORMATION LEE: 65 - Table 4 Reproductive status of fern species encountered in plots (4 replicates in each forest type). + X Total (Proportion) s.d. Nuboso Campbells Nuboso Campbells 5.5+1.3 Totalspecies 11.5 + 2.9 25(1.0) 16(1.0) Epiphytic with spores 6.5+1.3 2.8 + 9.6 20 (.80) 10 (.63) 2.3+1.7 + 6 with plantlets .3 .5 (.24) (.06) 1 with both 1.0+1.1 4 0(0) (.16) Non-reproductive 9.0 + 7.5 3.3+1.0 3 (.12) 5 (.31) - Table 5 Reproductive status of individual fern plants encountered in plots (4 replicates in each forest type). X + Total (Proportion) s.d. Nuboso Campliells Nuboso Campbells 10.5+1.3 94(1.0) 38(1.0) Total individuals 26.2 + 6.7 with spores 7.5+1.3 4.3 + 2.6 30 (.32) 17 (.45) with plantlets 4.2 + 4.0 0.3 + 0.5 1 7 (. 1 8) I (.03) 0(0) withboUi 1.0+1.1 4 (.04) Non-reproductive 14.2+10.4 5.5 + 2.9 57 (.60) 22 (.58) Discussion common been reported an pi tie t occumng One expect for a fern species (Farrar, 1968; Mickel, 1976). could Uierefore that more production wetter parts over a range of humidity, one might observe plantlet in tlic 30% of species (terres- of the range. In East Africa, plantlet production occurs in at least was & There a (Faden, 1973). epiphytic habit epiphytic) but associated wiUi die trial is we only but in studied, substantial proportion of epiphyUc species in both of the foresLs species sam where there a The production of may be selectively advantageous in areas is plantlets rapidly allowing the offspring to of disturbance, continual (not necessarily high) level montane have landslides areas tropical colonize exposed ground species); (the terrestrial A sporophyle large disturbance. and provide regular but unpredictable treefalls that potential game cnotype moribund fronds of unusual see nearly ravaged by time and enemies. not to It is ifoli damage while the di.sease phytopalhogens; may be hazardous by allowing access to additionally and may contamination escape planUet porophyte plant, the pcrennate m though and shoots, boUi The must regenerate rcx^Ls propagule vegetative (plantlet) from the Nephrolepis, in propagule derived from different orgiuis: different ferns the is Diplazmm (personal mirh^uU and D/.„„^..;,..» f.^,« .ho pt al 1983)1 in ctorv,. ;., rr.r.t . VOLUME NUMBER AMERICAN FERN JOURNAL: 66 83 2 (1993) and stolons permits dispersion of the propagule some distance from the parent sporo- ti (Richards, et al., 1983); plantlcts produced at or near the tips of long fronds can experience examine the incidence of plantlet production in certain species range, and to monitor the phenology of asexual and sexual rep plantlets be compared amone and snecies Many same species encountered in our mid-elevation study also occur lowland in and comparison. Acknowledgments Mike assistance, ;lcl Doris Campbell for access to their woodlands, and the Tropical Science Center for permission to work in the Monteverde Reserve. Financial support was provided by American the Latin Caribbean Center of Florida International University. Literature Afri 63:85-90, A Farrar, D. R. 1968. cultural chamber for tropical rain forest plants. Amer. Fern 63:85-90. J. Grayum. M. H., and H. W. Churchill. An 1987. introduction to tlie pteridophyte flora of Finca La Selva, Costa Rica. Amer. Fern 77:73-89. J. Zo MiCKEL The Experimental Biology Academic of Ferns. Press. Richards, J. H., J. Z. Beck, and A. M. Hirsch, 1983. Structural investigations of asexL Nephrolepis exaltata and Platycerium hifurcatum. Amer. Dot. 70:993-1001. J.