Colombia Forestal

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Authors: Román Ospina Montealegre, Andrés Felipe Ardila Fernández, Diego Fernando Martínez Bolaños, Edwin Rengifo Canizales

We determined the volume, biomass and carbon content per hectare for aerial forest Saladillo (Caraipa llanorum) at the Canapro Forestry farm (Puerto Carreño, Vichada), by destructively sampling 30 individuals. In order to fit a model to estimate variables, it was necessary to determine the fresh weight of the different components of each tree, and the volume of each stem. Subsamples were taken to determine the biomass of the stem, branches and leaves of each tree in order to obtain the density and carbon content of the wood. Forest inventory reported a density of 342 trees per hectare of C. llanorum with dbh ≥ 10 cm. This represents a volume of 37,4 m3 corresponding to 26,3 t·ha-1 of carbon. The wood density was 0,65 kg·m3-1 and the carbon content 52,96 %. To estimate the biomass of the species a best fit equation was used BT=e–9.47559+2.56189*ln(dap) with a biomass expansion factor of 1,52 reported for estimating the carbon balanced equation, C= e–10.2355 + 2.59771*ln(dbh).

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Authors: Diana Carolina Bohórquez

he Enrique Olaya Herrera National Park (c.a. 237 ha) is a protected area located in the eastern hills of Bogotá in a strategic ecological location. It forms part of the city’s Main Ecological Structure that maintains valuable landscapes in the region. However, the area is subject to a variety of ecological pressures and constraints that have contributed to its degradation. Based on landscape ecology theories, this study zoned the park according to its restoration potential with the objective of setting base-lines for the planning of restoration projects. Firstly, we characterized the physical, biotic and socio-dynamic components of the territory. Secondly, we selected the variables necessary for the evaluation and spacing of the restoration potential of each of these components. Finally, following the evaluation and weighting of the obtained potentials, and using GIS analysis, we determined which areas have high, medium or low ecological restoration potential, generating a 1:5000-scale cartography for the whole study area. The spacing of these landscape units is one of the main concepts of landscape ecology that allows the identification of priorities in projects that need rigorous planning and investment of technical and human resources. By doing this, it will likely contribute to the success of ecosystem restoration projects.

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Authors: Francia Nataly López Yela, César Polanco Tapia, Julio César Bermúdez Escovar

In this study, we evaluated the efficacy of four adhesives in the mechanical behavior of glulam on five species that are commercially utilized in Colombia (Acacia mangium Willd., Campnosperma panamense Standl., Gmelina arborea Roxb., Eucalyptus tereticornis Sm. and Pinus caribaea Morelet). The adhesives tested were phenol resorcinol formaldehyde (PRF), melamine urea formaldehyde (MUF), polymer emulsion of isocyanate (EPI) and polyurethane (PUR), all of them handled according to the manufacturer’s instructions. We also assessed the spread factor of 350g/ cm-2 under controlled humidity and temperature. To establish resistance parameters we performed mechanical static bending experiments according to the Colombian Technical Standard (NTC 663). We measured the modulus of elasticity, modulus of rupture, and work to maximum load in bending. The results showed an optimum mechanical performance for all of the wood/adhesive combinations rendering their use feasible for construction purposes in Colombia.

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Authors: Rodrigo Bernal & María José Sanín

We studied the populations of the Quindío Wax Palm (Ceroxylon quindiuense) surviving in deforested areas of the upper Cocora Valley, Quindío, Colombia, by comparing photographs taken in October 1988 and December 2012 at the same sites. The seven pairs of images cover an area of ca. 26.4 hectares, corresponding to 7.4 % of the deforested area of the upper valley where most of the population persists. During the 24 years of the study the number of palms included in the sample units decreased from 585 to 469, a reduction of 19.8 %. Most palms that died during this period were senescent plants over 40 m tall, with estimated ages of 139-169 years. Considering their growth rates, we calculate that during the next 47 years, most palms surviving today will reach heights greater than 40 m and will probably die, without leaving young palms behind to replace them. With this severe reduction in the number of palms one of Colombia’s most emblematic Andean landscapes and a top tourist attraction will disappear. We present the status of the palm stands during the current century, and recommend their immediate recovery through the creation of a National Sanctuary of the Quindío Wax Palm and recognition of Ceroxylon quindiuense as an umbrella species. This would perpetuate the existence of Colombia’s National Tree at this site, increasing the potential for the socioeconomic development of the central region of Colombia.

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Authors: Winston Wilches-Álvarez, Manuel Fernando Botero-Á & Francisco Cortés-P.

The composition and abundance of macroinvertebrates associated with the terrestrial bromeliad Guzmania mitis in two fragments of oak grove with different conservation status in Arcabuco, Boyacá were studied. The study aimed to establish whether there are differences in the composition and abundance of macroinvertebrates between fragments and their possible causes, and to identify groups of macroinvertebrates that may serve as indicators of alterations to oak groves. Two macroinvertebrates samples were made, one in the dry season in February and one in the rainy season in May 2006, in two physiognomically and structurally different oak grove fragments. Nine bromeliads per fragment were collected from which the macroinvertebrates were identified. 12 258 individuals were found, belonging to 20 orders, 52 families and 89 morphospecies, with orders Diptera and Coleoptera prominent in larval stages. The cluster analysis in the disturbed fragment had a higher abundance of Chironomidae and low abundance of Scirtidae, whereas the conserved fragment had low abundance of Chironomidae and high numbers of Scirtidae. No significant relationship was found between abundance, diversity (Shannon) and richness (Margalef) and variation in physicochemical parameters (dissolved O2 and pH) measured in bromeliads. The families Chironomidae and Scirtidae are proposed as good candidates for possible indicators of the degree of intervention in oak groves.

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Authors: Diego Felipe Correa-Gómez et al.

The study of plant dispersal systems improves our understanding of forest regeneration, the dynamics of plant populations and the ecological relationships that emerge within ecosystems. In this study we analyzed the patterns of seed dispersal systems for Colombia, in relation to the Amazonian, Andean, Caribbean, Upper Magdalena, Middle Magdalena, Orinoco and Pacific geographic regions. Based on information on identity and abundance of plants found in 101 one hectare vegetation plots, we explored the changes in the relative frequency and relative abundance of plant dispersal systems among the geographic regions. Additionally, we explored the floristic affinities between the regions, as well as the representativeness of families and genera per dispersal system. Endozoochory was highly represented at different taxonomic levels (species, genus, family), and its relative importance changed among the different geographic regions. Those changes could be explained by ecological differences between the regions.