Colombia Forestal

13

Authors: Jonnier F. Herrera, Alonso Barrios, Ana M. López & Víctor Nieto

In the management of forest plantations decisions on tree bucking are important as they directly affect profitability. Proper and efficient use of stems is necessary in order to maximize the economic benefits derived from the forestry sector. There are various possible combinations for sizing and assigning different forest products according to market requirements. This study aims to develop a methodology based on heuristics and dynamic programming for bucking optimization of individual stems to maximize the economic value of the tree. The evaluation of bucking models was conducted through a practical application on stems of Eucalyptus tereticornis growing on the Colombian Atlantic coast. An algorithm for generating potential points along the commercial bole of the tree was used and an algorithm based on dynamic programming determined the optimal combination of products to be obtained in the evaluated stem, by imposing constraints on the model based on the size of the demanded products. A comparison of the results obtained with a simulation of sequential bucking did not find any difference between the two methods, mainly due to the marked differentiation between products used in the practical example. This methodology can be used to optimize the bucking of any species that has taper functions to predict upper-stem diameters and heights and commercial volumes along the stem.

15

Authors: Héctor Iván Restrepo O., Flavio Moreno H. & Claudia Helena Hoyos E.

The urban forest of the municipalities of the Aburra Valley, Colombia, is deteriorating as a result of drought and heat stress, air pollution, urbanization, pests and diseases. In order to record the symptoms of progressive deterioration (DP) of trees such as wilting of branches and downward drying, a sample of 11 710 individuals from 25 tree species and palms in the metropolitan area of the Aburrá Valley was carried out. A multivariate logit model was estimated to relate the incidence of DP with dasometric characteristics of individuals, the planting site and the extent of damage. 720 individuals with DP (incidence 6.1%) were found. The logit model had a satisfactory fit to the data and showed that there is a statistically significant relationship between the incidence of tree deterioration and tree diameter, location (municipality), species, planting site (green, hard floor, container ) and other damaging factors.

17

Authors: Heriberto David-Higuita & Esteban Álvarez-Dávila

Floristic composition of vascular plants and their distribution is reported for growth habits in a low montane rain forest (2600 m and 2500 mm/yr mean annual precipitation) in the northern Andes, based on a plot of 1 ha. The samples collected represented 318 species/morphospecies, 82 families (nine of which were pteridophytes) and 173 genera. 78% of the samples were identified to species. Groups with most species are pteridophytes (sensu lato), Orchidaceae, Asteraceae, Rubiaceae, Melastomataceae and Piperaceae, that represented 44% of all species recorded. The most diverse genera are Peperomia, Elaphoglossum, Mikania, Anthurium, and Miconia. Three species endemic to Antioquia (Brunellia trianae, Meriania antioquiensis and Mikania fragrans) were found. The individuals found in the plot represent 47% of the species, 48% of the genera and 60% of the families found in Arví Park, a reserve of 11400 hectares in which the plot was located. The plot had 108 species, 30 genera and one family not previously reported for Arvi Park. The number of common taxa between the plot and the Arví Park was 144 species, 142 genera and 69 families. Species richness/family in the plot accounts for 89% of the variation of species richness/family in the Arví Park, and 75% of the generic richness. We conclude that detailed floristic inventory of known area plots provide information representative of the regional flora and permit a rapid approximation of its biodiversity.

21

Authors: Juan F. Pérez, Rolando Barrera & Gloria Ramírez

The technical, energy, social and environmental benefits of the integration of commercial forest crops in Colombia under biorefinery concepts are evaluated. This concept is part of various programs and government policies that consider the energy use of biomass as an alternative source to the silvicultural potential of the country. In this paper we review some specific processes that can be evaluated as integration strategies with high potential to use the wood planted in Colombia under biorefinery concepts. The processes considered are low-middle power gasification, industrial scale gasification to high quality biofuel production, wood pretreatment to improve the solid biofuel and alternative methods for biochar production. Finally, we also review the value-added wood products market. To conclude we highlight the potential of Colombian forest in this industry, Through strategic alliances between universities, research centers and the forestry sector, more efficient and innovative development of new value-added products should be sought, taking advantage of the unexplored market opportunities in Colombia for bioenergy and bioproducts. This review aims to advance knowledge on the features and possible uses of forest species to produce bioenergy, biofuels, and bioproducts sustainably.