3.1.2. Vegetation Types
The forest habitats in the Monteverde area fall into
three general vegetation types: (1) seasonally dry but
mostly evergreen forest on the Pacific slope in the rain
shadow of the higher peaks and ridges of the Conti-
nental Divide below 1500 m, (2) perpetually dripping
cloud forest on the mountain top from 1500 to 1850
m on the Pacific slope and down to 1400 m on the
Atlantic slope, and (3) nearly aseasonal rain forest on
the Atlantic slope below 1400 m. The change in veg-
etation parallels a gradient in increasing moisture
from the Pacific to the Atlantic side. Increase in mois-
ture is partly due to an increase in annual rainfall to-
ward the Continental Divide and Atlantic slope (see
Chap. 2, Physical Environment), but cloud condensa-
tion and wind-borne mist that occur in the cloud forest
during the dry season also form important compo-
nents of the moisture regime in the Tilaran Moun-
tains. These three forest types are divided into seven
life zones (Holdridge 1966, 1967, 1978, Tosi 1969,
Bolafios and Watson 1993) and a series of edaphic and
atmospheric vegetation types within the life zones.
Pacific slope seasonal forest. Extending from about
700 m to 1500 m, this area receives an annual rain-
fall of 2000-2500 mm and experiences a 5-6-month
dry season. Except for areas close to the divide (e.g.,
upper Rio San Luis), little moisture comes in from
wind-blown mists during the dry season. The forest
is mostly evergreen, with a few deciduous species that
remain leafless for 1-3 months. Less than 10% of the
canopy is leafless during the dry season. With a height
of 25-40 m, the forest is composed of tall straight
trees forming a closed canopy with a fairly open un-
derstory made up of shrubs, treelets, and tree sap-
lings. Herbs are scarce, except in wet spots, and a
layer of dry leaf litter accumulates on the ground.
Epiphytes are uncommon below 1400 m, but they
occur as scattered individuals or in dense mats on
large exposed branches. This area includes the pre-
montane moist and premontane wet forest life zones,
and small extensions of the tropical moist forest life
zone. The communities of Monteverde, Santa Elena,
and San Luis, and all of the villages lying northwest
as far as Tilaran occur within this zone.
Cloud forest. Most of the area above 1500 m in eleva-
tion on the Pacific slope (above the communities of
Monteverde, Santa Elena, La Cruz, and Las Nubes)
up to the Continental Divide and extending down to
1300-1400 m on the Atlantic slope supports a luxu-
rious cloud forest. With annual rainfall of 2500-3500
mm and frequent mist and cloud cover in the dry sea-
son, this evergreen forest remains wet throughout theyear. Leaf litter in the understory rarely dries out for
more than a few days, usually near the end of the dry
season in March or April. Canopy height varies from
20 to 40 m in sheltered sites to 5-10 m in the elfin
forest on ridges and peaks exposed to the trade winds.
The forest is characterized by a diverse and abundant
epiphyte community, a more broken canopy than on
the Pacific slope, and a dense understory of shrubs,
treelets, and large herbs (Nadkarni et al. 1995, Matelson
et al. 1995). The cloud forest habitat includes the lower
montane wet forest and lower montane rain forest life
zones. No towns or villages occur in this vegetation
zone in the Monteverde region.Atlantic slope rain forest. The forest on the Atlantic
slope below 1400 m receives annual rainfall ranging
between 3500 mm and more than 7000 mm (measured
at Eladio's Refuge in the Penas Blancas valley at 820
m; M. Fogden, pers. comm.). The rain in this area is
well distributed through the year, resulting in an al-
most aseasonal climate. A barely noticeable drier
period occurs during March and April. Canopy height
(20-40 m) varies with exposure to the trade winds and
steepness of the terrain. Forest stands with the larg-
est trees and least broken canopy occur in sheltered
valleys and on gentle slopes below 1200 m where huge
buttressed trees commonly exceed 50 m in height. On
exposed steep ridges, the forest is reduced to 15-20
m in height with a broken canopy, straggly structure,
and low diversity. The Atlantic slope ridges appear
to receive more precipitation as mist and drizzle; the
valleys experience more rain in the form of thun-
dershowers. The life zones in this area include pre-
montane wet forest, premontane rain forest, and tropi-
cal wet forest—premontane transition (Tosi 1969,
Bolafios and Watson 1993).3.1.3. Life Zones
Seven of Costa Rica's twelve life zones are represented
in the Monteverde area (Tosi 1969, Hartshorn 1983,
Bolafios and Watson 1993; Fig. 1.4). Life zones are
defined on the basis of mean annual temperature and
rainfall data (Table 3.1). Because the life zone system
does not incorporate the seasonal distribution of rain-
fall, variation in vegetation may occur within a life
zone in the Monteverde area, depending on exposure
of the site to the trade winds in the dry season versus
protection from the winds in the rain shadow of the
Tilaran Mountain peaks. Although the life zone sys-
tem provides a useful classification method, life zones
do not have sharp boundaries; they blend into one
another along the gradients of temperature, moisture,
and elevation. In the descriptions of the Monteverde
life zones that follow, Spanish language names and41 Plants and Vegetation