Monteverde : Ecology and Conservation of a Tropical Cloud Forest

Figure 9.8. Map of study site in

Monteverde. Small circle indicates

the field station of the Monteverde

Cloud Forest Preserve. Black square

represents the 4-ha study plot.

(From Nadkarni etal. 1995)

Studies of root-soil interactions in tropical mon-
tane forests have focused almost exclusively on the
forest floor. In Monteverde and many other tropical
forests, however, a considerable amount of dead or-
ganic matter exists within the crowns of trees (Pocs
1980, Nadkarni 1984). This epiphyte-generated
"crown humus" (sensu Jenik 1973) is produced from
the decomposition of epiphytic plants, the bark of

host trees, intercepted canopy detritus, and in

organic nutrients impounded from atmospheric

sources (Nadkarni and Matelson 1991). Material can

accumulate up to 30 cm thick on the surfaces of large

branches, in bark crevices, and in the crotches of bi-

furcating tree trunks and supports a great diversity

and biomass of epiphytic plants and associated in-

vertebrates and vertebrates, some which are unique

Table 9.1. Soil description of leeward cloud forest study area in Monteverde (Vance and Nadkarni 1992).

Approximate

Horizon

H/root mat

A!

A 2 /B!

B 2

Depth

(cm)

0-15

15-20

20-85

85-180

pH (H 2 0)

4.4

4.7

5.3

5.5

Colora

Dark reddish brown

5 yr 3/3

Dark brown

7.5 yr %

Strong brown

7.5 yr 4/6

Strong brown

7.5 yr 4/6

Texture

Loam

Loam to sandy

loam

Clay loam

Structure

Weak to moderate

crumb

Weak to moderate

crumb

Weak crumb to

moderate sub-

angular blocky

Moderate sub angular

blocky

Bulk

Density

(g/cm^2 )

0.046

0.31

0.50

0.63

314 Ecosystem Ecology and Forest Dynamics