Monteverde with a ropey, open trunk. However, on
the Atlantic slope it commonly reaches maturity as a
hemiepiphytic shrub. Ficus pertusa usually achieves
reproductive maturity while a hemiepiphyte and less
commonly becomes a free-standing tree. Ficus tuerck-
heimii typically becomes a huge canopy tree, the most
common strangler in the Monteverde community and
lower cloud forest (1300-1550 m). The sympatric F.
velutina becomes a large canopy tree; it grows in moist
canyons and sheltered sites.
Several species in families unrelated to the figs
have evolved similar growth forms, including Alzatea
verticillata (Alzateaceae), a hemiepiphytic shrub that
occasionally becomes a large tree with the growth
form of a strangler fig. Ceiba rosea (Bombacaceae),
common at Eladio's Refuge and Poco Sol, is a hemi-
epiphyte with palmately compound leaves and spiny
roots that can become a free-standing tree. Clusia spp.
often become tree-sized hemiepiphytes in the cloud
forest, especially on the highest peaks and ridges.
Although some species are described as stranglers
elsewhere in the neotropics, the species at Monte-
verde have not been shown to kill their hosts. Cous-
sapoa spp. (Cecropiaceae) commonly grow as large
hemiepiphytes on the Atlantic slope from San Gerardo
to Poco Sol. They occasionally reach tree size and
develop the distinctive growth form of strangler figs.
Ferns. A total of 358 species of ferns and fern allies
in 25 families have been identified at Monteverde (see
Bigelow and Kukle, "Ferns," p. 89 and Appendixes 1
and 2). The species are divided between terrestrial
herbs (144 species, 40%) and epiphytes (177 species,
49%; see Table 3.7). Fifteen species grow as trees and
shrubs with distinct erect trunks, and 19 species
grow as tree trunk climbers, including several that be-
come semiwoody vines, such as Lomariopsis spp.
(Lomariopsidaceae), Polybotrya alfredii (Dryopteri-
daceae), Polypodium ptilorhizon (Polypodiaceae),
Salpichlaena spp. (Blechnaceae), and Sticherus spp.
(Gleicheniaceae).
Ferns are most abundant in the cloud forest,
where the tree trunks and canopy support many
epiphytic species. The proportion of terrestrial
species is much higher in drier forest habitats,
where several species commonly grow on rocks
(e.g., Polypodium plumula, P. polypodioides, P.
rhodopleuron, Selaginella pallescens). Only 45 spe-
cies (13%) of ferns have been collected on the dry
Pacific slope below 1200 m; 60% grow in the mon-
tane zone above 1200 m; 58% of the species occur
on the Atlantic slope, reflecting the extremely
wet conditions found there throughout the year
(Table 3.5). The largest genera of ferns at Monteverde
are Polypodium (18 spp.), Asplenium (19 spp.),
Thelypteris (24 spp.), and Elaphoglossum (38 spp.;
Appendix 1).
Tree ferns occur in the families Cyatheaceae (Also-
phila, Cyathea, Sphaeropteris), Dicksoniaceae (Dick-
sonia gigantea), and Thelypteridaceae (Thelypteris
decussata) (Fig. 3.17). Not all members of the Cya-
theaceae develop a tree-like growth form (e.g., Cnemi-
daria mutica). Reaching 8 m in height, Sphaeropteris
brunei is the largest tree fern at Monteverde, with a
distinctive trunk covered with dense beige hair-like
scales. The distribution of tree ferns along an ele-
vational gradient crossing three life zones was de-
scribed at Monteverde by Lee et al. (1986). Tree ferns
were most abundant and diverse in the lower mon-
tane rain forest life zone, where a total of seven spe-
cies occurred. They found only three species in the
lower montane wet forest, and none in the premon-
tane wet forest. However, an Alsophila sp. grows in
the moist stream canyons down to 1200 m within the
premontane zone (W. Haber, pers. obs.).
Some terrestrial ferns form plantlets, which are
small plants that grow on fern fronds and that can
establish new plants vegetatively. Koptur and Lee
(1993) found species capable of producing plantlets
to be more common along the Nuboso trail (lower
montane rain forest life zone) than in the drier forest
of Campbell's woods (6% of species in the 24% of
species in the lower montane wet forest life zone).Bryophytes. Knowledge of Monteverde's bryophytes
is rudimentary. However, significant collections have
been made by G. Dauphin, S. Ingram, R. Lawton, M.
Lyon, and S. R. Gradstein. Floristic studies of the Monte-
verde bryophytes provide species lists (Reed and
Robinson 1971, Gradstein et al. 1994, Sillett et al.
1995). Approximately 190 species of bryophytes in 39
families (133 liverworts, 56 mosses, and 1 hornwort)
were collected from the 4-ha Nadkarni tree plots (Grad-
stein et al. 1994; Gradstein, "Bryophytes," p. 78 and
Haber, "Description," p. 90). The bryophyte flora of
the canopy and understory are distinct. Liverworts are
generally more abundant and diverse than the mosses;
liverworts make up the bulk of epiphylls (see Gradstein,
"Bryophytes," p. 78; Morales, "Plants Growing on
Living Leaves," p. 80).Fungi and lichens. Fungi and lichens at Monteverde
have been studied even less than bryophytes. Lesica
and Antibus (1990) examined epiphytes at Monte-
verde and La Selva Field Station for vesicular-arbus-
cular mycorrhizal fungi (Maffia et al. 1993; see Maf-
fia, "Mycorrhizae," p. 338). They found mycorrhizae
associated with orchids and with most Ericaceae. How-
ever, many canopy epiphytes belonging to families that
generally support mycorrhizal associations elsewhere60 Plants and Vegetation