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.

8

Authors: Eloisa Lasso, Lucas Santiago Barrientos

The role of animals as seed dispersal vectors is widely acknowledged, including dispersal by reptiles (saurochory). Most reports of saurochory have been via endozoochory, through feces deposition. We present the first evidence of epizoochory in Iguanas from a dry forest in Colombia via seeds attached to the snout. Our results show that seeds of a cactus Melocactus curvispinus ingested by iguana suffers from their passage through the digestive tract while seeds transported while attached to the snout germinate faster and in higher numbers. Our data suggest that we may have overlooked an alternative means of seed dispersal by lizards that does not comprise a passage through their digestive tract, and that deserves further attention for the understanding of dry forest ecology.

11

Authors: María Cristina Gallego-Ropero & Beatriz Salguero Rivera

The ant assemblages of a fragment of secondary tropical dry forest located in the Botanical Garden of Cali are presented. Two habitats were chosen: a fragment of forest and a pasture matrix. Samples were taken monthly for six months, using a linear transect of 100 m, with 10 stations spaced 10 m. At each station pitfall traps, epigeal bait and arboreal, sifting and removal of 1 m2 of litter and manual capture survey techniques were applied. Richness, abundance and diversity of ant habitats were determined. Correlation coefficients and regression between temperature, relative humidity and richness of ants were calculated. A total of 13 170 ants representing 55 species, 35 genera and six subfamilies were collected. The forest had the highest species richness with 90.9%. This wealth of diversity indicates the conservation value of the Valle del Cauca myrmecofauna. Although the forest is in the process of regeneration, strongly disturbed by constant fire and human intervention, the ant species richness shows that it remains an invaluable source of biological resources for the conservation of species.

14

Authors: Viviana Londoño Lemos & Alba Marina Torres González

Characterization of long-term vegetation in a tropical dry forest (TDF) that is in the process of regeneration permits establishment of patterns of composition, structure and dynamics of plant communities and sheds light on the different stages of plant succession. In this study, the plant community of ecoparque Bataclán, Cali, Colombia was evaluated by determining its structure and composition in two regeneration strategies. One strategy consisted of natural regeneration with bamboo barriers and the other of natural regeneration without bamboo barriers. Three permanent plots of 500 m2 were established in each regeneration strategy (six plots in total). Composition and structure was determined, taking into account all the growth habits, with different sampling methods. We found no significant differences between vegetation structure and composition of the two strategies for forest regeneration. forty-one species belonging to 27 families were recorded (trees and shrubs 58.5 %, herbs 24.4 %, climbers or scandents 14.6 %, epiphytes 2.4 %). The dominant family was Melastomataceae and the dominant species was Miconia prasina. The orchid Catasetum ochraceum and the grass Thrasya petrosa were indicator species for high luminosity. We conclude that the plant community is in an early successional stage, where there is a mixture of planted and naturally regenerated species in the zone, characterized by pioneer species from TDF and other nearby life zones.

20

Authors: Hernando Vergara Varela

Vegetation of dry forest ecosystem of the Patia valley located in the department of Cauca has been altered and replaced by crops and pastures. The forest remnants were characterized in terms of their structure and floristic composition at altitudes between 500 and 800 m. This study evaluated changes in land cover using aerial photographs and satellite image as input to produce land cover maps in order to assess changes associated with land use types. Data were analyzed by multivariate methods using the TWINSPAN program to produce a vegetation classification, identifying six vegetation structure types and six floristic types. The floristic gradient thrown by the program describes structural types, ranging from forests to shrublands and grasslands. Successional plant communities reflect conditions of the fragments, Citharexylum kunthianum community contrasts with riparian forests determined by Eugenia sp the dominant specie in disturbed areas. Handroanthus chrysanthus community shows a transition to xerophyte vegetation of the south of Colombia. Land use types and land cover classes have remained since 1961, increasing pasture cover. Tropical dry forests are reduced in its structure, considering that forests are disturbed. In the long history of the land use and disturbance of this area, a reduction in forest fragments is evident, social and economic factors are a force for a change in plant communities in rural areas.

23

Authors: William Vargas

Information on the flora of the dry forests of southern Huila province was revised, with emphasis on intermediate pioneer species that can support processes of ecological restoration and conservation of biodiversity, these data were compared with those obtained in the field over the past 30 years. According to literature, 203 intermediate pioneer species distributed in 123 genera and 45 botanical families were identified for Huila, while for La Jagua field data recorded 155 species grouped in 111 genera and 45 families among which Leguminosae, Rubiaceae, Euphorbiaceae, Malvaceae, Melastomataceae and Moraceae are the most important families. The main types of hedges in the landscape of La Jagua are described, with notes on major plant species, conservation status and representative fauna. A list of 155 intermediate pioneer species is proposed, with the most important attributes for use in processes of conservation and ecological restoration of dry forests in the region. This type of species is key in generating habitat, connectivity, resources for wildlife and production of resources such as firewood and wood for communities, within a model of landscape management tools.