have never
reattained the majesty they had during the days of Venice's power when
they could be called upon to furnish 400 shiploads of straight oak stems
for Venetian fleets, but in 1970 they still constituted nearly half of
all forests. The oaks are valuable not only for their economic worth as
fuel and lumber but also because the leaves of deciduous varieties and
the undergrowth encouraged beneath them are excellent soil builders.
Occurring at moderate elevations, however, they have been accessible and
overexploited. Lowland oak forests contain poorer species that rarely
grow in excess of thirty feet tall, but the thick undergrowth they
usually allow provides stability and improves the alluvial soil. The
finer and more valuable species occur at middle and higher elevations.
Oak forests predominate between 1,000- and 3,000-foot elevations but
occur up to about 4,000 feet.

Beech trees appear at all elevations between 3,000 feet and the
timberline. They predominate in northern areas between about 3,500 and
6,000 feet. In the south they flourish at the same elevations but are
usually outnumbered by conifers. Beech is excellent hard wood, and its
leaves are among the best of soil builders. The trees generate most of
the humus themselves, as their canopies interlace tightly in mature
forests, permitting relatively little undergrowth to flourish on the
forest floors beneath them. Mature forests have survived in many of the
remote, inaccessible areas that beech species prefer. The most copious
forests are in cloud forest regions where cloud cover is almost
constant, rainfall is frequent, and temperatures do not usually reach
the extreme highs.

The better conifers, usually including several pine species in the
north and fir, with lesser numbers of pine and spruce, in the south,
coexist with beech but tolerate poorer soils and tend to predominate at
the highest elevations. Although they tend to have less continuous
canopies than beech forests, they do not encourage undergrowth. Their
needles, along with rapid decay of their softer dead wood, however, can
create deep humus. The poorer quality lowland pines do well at
elevations down to sea level and will tolerate certain conditions,
although not overly poor drainage, in which the oak will not survive.
Its woods usually have discontinuous canopies and allow dense maquis and
other lower shrubs to flourish beneath them.

True mixed woods, sometimes referred to as karst woods