Table 3.1. Characteristics of the Holdridge life zones occurring at Monteverde.Life Zone
Tropical moist forest (premontane transition)
Tramontane moist forest
Premontane wet forest
Lower montane wet forest
Lower montane rain forest
Premontane rain forest
Tropical wet forest (premontane transition)
Elevation
(m)
600-800
700-1000
800-1450
1450-1600
1550-1850
700-1400
0-700Mean Annual
Rainfall
(mm)
1950-3000
1200-2200
2000-4000
1850-4000
3600-8000
4000-7000
4000-5500Mean annual
Temperature
(°C)
21.5-24
17-24
17-24
12-17
12-17
17-24
21.5-24Dry Season
Duration
(months)
0-5
3.5-5
0-5
0-3
0-3
0-2
0-3.5Canopy
Height
(m)
30-40
ca. 25
30-40
25-35
20-30
30-40
30-50
The life zones are arranged in sequence along a transect across the mountains from the Pacific slope to the Atlantic slope.
Source: Data are from Bolanos and Watson (1993).codes, as they appear on the life zone maps published
in Costa Rica, are shown in parentheses. Tree species
that are common or characteristic of each life zone in
Monteverde are listed in Table 3.2.Tropical moist forest-transition to premontane (bosque
humedo-Tropical [bh-T] and bh-TA, transicion a pre-
montano). This life zone forms a broad band along
the Pacific slope of the Tilaran Mountains from near
the Inter-American Highway to about 700—800 m. The
narrow, northern edge is classified as a transition to
premontane. The boundary between the typical tropi-
cal moist forest zone and its premontane transition lies
halfway between the villages of San Luis and Guacimal.
The Chepe Rojas farm, which forms part of the MCFP
Corridor system, is within the transition zone 2-4 km
downriver from the San Luis bridge; it protects the
largest fragment of this forest type in the area. Another
small band of this transition zone occurs in the hills
at the northwest end of Laguna de Arenal. This life
zone experiences a dry season ranging from 0 to 5
months; on the Pacific slope below Monteverde, the
dry season lasts almost 6 months (mid-November to
mid-May). The natural forest is mostly evergreen,
and epiphytes are common. Soils are well suited for
agriculture (Bolanos and Watson 1993).Premontane moist forest (bosque humedo-Premontano
[bh-P]). This life zone occurs on the Pacific slope at
700-1000 m in a band 2 km x 11 km from Los Cerros
northwest to the village of San Rafael, and extending
into the upper canyon of the Rio Guacimal below
Monteverde, between 900 and 1100 m in the lower
part of Bajo del Tigre. This drier habitat (at the same
elevation as the premontane wet forest zone results
from a rain shadow caused by the high plateau and
peaks above Monteverde (Cerros Amigos, Chomogo,
and Sin Nombre). The natural vegetation is evergreen
forest with a small component of deciduous species
and relatively few epiphytes. Only scattered smallfragments of this forest remain in the area. This life
zone, which also covers a large part of the Central
Valley around San Jose, Heredia, and Alajuela, may
have the most favorable climate in the country for
humans (Bolanos and Watson 1993). The soils sup-
port a diversity of agricultural activities, predomi-
nantly coffee cultivation.Premontane wet forest (bosque muy humedo-Premon-
tano [bmh-P]). This life zone forms a wide band along
the Pacific slope from about 800 to 1500 m, encom-
passing the communities of Monteverde, Santa Elena,
and most of the San Luis valley. Straddling both slopes,
this life zone spans a range in climate from the highly
seasonal San Luis valley to the constantly wet Atlan-
tic slope above Laguna de Arenal. The range of a few
tree species spans this life zone, despite its diverse
climate regime (Table 3.2). The natural vegetation is
an evergreen forest with a few deciduous species, es-
pecially on the Pacific slope, with moderate epiphyte
diversity and abundance. Primary tracts of this forest
type occur within the Monteverde community and
downslope into the upper San Luis valley and across
the San Luis River into the Buen Amigo area. Most of
the towns and villages in the Monteverde region are
located within this life zone. The soil and climate are
well suited to agriculture (Bolanos and Watson 1993).
Most of the locally grown coffee is produced here.
Although this life zone is not considered cloud for-
est, during the wet season the area surrounding the
Monteverde community receives an almost daily bath
of ground-level clouds from the Pacific side.
The high ridge extending northwest from Las
Nubes to La Chirripa (900-1200 m) is classified as a
zone of transition between premontane wet and pre-
montane rain forest (bmh-PA). An undescribed species
of Fabaceae (Dalbergia tilarana N. Zamora, ined.)
grows on this ridge and has not been been found any-
where else. This forest type also occurs above the
town of La Tigra near the villages of San Gerardo and42 Plants and Vegetation