Natural regeneration characteristics of
native Bolivian tree species
Hannes Cosyns, Robert De Wulf, Manuel Ojeda Camacho
Tel: 09 221 62 57
E-mail: hannes.cosyns@ugent.be
Functie: student
The knowledge of the ecological requirements and the life cycles of tree species in the tropics
is very limited. Information is particularly lacking about formerly economically less important
tree species that are gaining interest and are presently exploited. The importance of
sustainable management in topical forest is increasing and in Bolivia measures have already
been implemented in the legislation. Nevertheless, one of principal problems in Bolivia is the
insufficient regeneration of several economically important timber species that are currently
exploited. Inducing regeneration of these species by appropriate silvicultural management is
perhaps an important step towards achieving a sustainable use of the Bolivian forests and
therefore knowledge about the regeneration characteristics of these tree species is crucial.
This study aims to contribute to research evidence about the natural regeneration of
economically important Bolivian tree species present in the primary humid evergreen forest of
Bolivia. The study area is located on the east side of the Andes mountain range in the forest of
Valle del Sacta at 17°05’ S longitude and 64°41’ E latitude. The general objectives are to
explain and predict spatiotemporal patterns of seedlings as well as their growth rates under
different environmental conditions. Special attention was given to the prevailing light
conditions and their influences on seedling characteristics. Light conditions were measured
indirectly with a hemispherical camera and were acquired on plot level.
For Eschweilera coriacea, one of the predominant species in the study area, the first results
demonstrated that initial seedling densities were related to the distance to the mother trees.
This distance-density relation changed over time and densities of sapling with larger
dimensions (height > 150cm and dbh < 10cm) did not display any relation with the distance to
the mother tree. Seedling density dynamics were driven by distance dependent mortality
rather than differences in radiation among sites. Nevertheless, indirect indications of increased
survival rates at sites under higher light conditions were observed. Hence, based on the
distance towards the closest mother tree, the dbh of the mother tree and the time of
observation, it was possible to model the seedling density of Eschweilera coriacea at any
location in the forest.