phytes have thick, leathery, fleshy, or waxy leaves
or swollen stems that retain water, such as those in
Asteraceae (Neomirandea spp.), Cactaceae (Epiphyllum
lepidocarpum), Ericaceae (Satyria meiantha; Fig. 3.4),
Loranthaceae (Psittacanthus mmiflorus), Orchidaceae
(Epidendrum obesum), Solanaceae (Lycianthes synan-
thera), and Viscaceae (Phoradendron spp.).
Plants often produce larger leaves in the shade
than in the sun. A few tree species have leaves with
different shapes in the shade than in the canopy. The
shade leaves of Dendropanax arboreus have three
large lobes (shaped like a dinosaur footprint),
whereas their canopy leaves are simple. Leaves of
both types occur on saplings in light gaps. Saplings
of Roupala glaberrima and R. montana typically
have odd-pinnate compound leaves, but adults have
simple leaves about the same size as a leaflet of the
juvenile leaves.
3.1.6. Species Richness and Diversity
Our knowledge of the Monteverde flora is the prod-
uct of about 20,000 plant collections made between
1975 and 1995. Valerie Dryer (1979) produced a list
of about 850 vascular plant species from the Monte-
verde area, based on collections made during a Smith-
sonian Institution/Peace Corps assignment at Monte-
verde. A tree list for a series of Costa Rican research
sites included 272 species known from Monteverde
(Hartshorn 1983). In 1990, a list of vascular plants
recorded from the Monteverde area above 700 m con-
tained just over 2000 species (Haber 1991). An update
of this list contains 3021 species, including a total of
755 species of trees (Appendix 1). New records for the
area and undescribed species are being added con-
tinually (e.g., Atwood 1995, Hammel 1997, Poveda
and Gonzalez 1997).Figure 3.4. Satyria meiantha (Ericaceae) branch and
flowers. Drawing by Willow Zuchowski.Species richness. Species richness is defined as the
number of species occurring within a designated area.
About 9000 vascular plant species are known from Costa
Rica (Institute for Biodiversity database for the Manual
to the Plants of Costa Rica Project [Manual de las Plantas
de Costa Rica], B. Hammel, M. Grayum, and N. Zamora,
principal investigators). Thus, about one-third of the
Costa Rican flora has been recorded growing outside of
cultivation in the Monteverde area (see Bigelow and
Kukle, "Ferns," p. 89, and Appendix 1).Diversity within and between habitats. Forest inven-
tories within life zones and permanent forest plots at
Monteverde suggest that species richness of trees is
lower within habitats in the mountains than in the wet
lowlands (Gentry 1990, Lieberman and Lieberman
1994, Nadkarni et al. 1995; Table 3.6). Overall, spe-
cies richness tends to be highest in the wettest low-
land sites and to decrease in montane habitats and
drier habitats with strong seasonality (Gentry 1982,
1990). Even though species richness per unit area (al-
pha species richness) in Monteverde may be lower
than in the Atlantic lowlands, the high diversity of
habitats along the steep moisture gradient across the
mountains at Monteverde results in high species rich-
ness in a small area (beta species richness). The ex-
tremely rich epiphyte flora of the cloud forest adds
substantially to the total species richness of the Mon-
teverde region compared with the lowlands (Table 3.7,
Hammel 1990). Permanent plots in which the trees have
been measured, marked, and in some cases mapped
have been established at nine sites near Monteverde
(Table 3.6; see Haber, "Description," p. 90).Endemism and new species. Since 1975,167 species
new to science have been collected in Monteverde,
equaling 5.5% of the local flora. Of these, 88 species
(53%) are thought to be endemic to the Monte-
verde region. Of the entire Monteverde flora, about
10% of the species are endemic to the Cordillera de
Tilaran.3.1.7. Diversity and Distribution
of Growth Forms
The distribution of species among the life zones at
Monteverde is poorly known, but the numbers of spe-
cies recorded from the three major vegetation types
have been tabulated (see Sec. 3.2; Fig. 3.5). The mon-
tane zone (above 1200 m) supports 1708 species (57%
of the total flora). The Atlantic slope (700-1200 m)
has 1390 species (46%), and the Pacific slope (700-
1200 m) supports only 737 species (25%). The latter
area merits special attention because of the presence
of rare and undescribed species and the high rate of50 Plants and Vegetation