Colombia Forestal

123-141

Authors: Diego Simijaca, Bibiana Moncada, Robert Lücking

Quercus humboldtii is a dominant element in the high Andean forests of Boyacá, Colombia. Despite being an umbrella species, it has a per-capita consumption of 1300 Kg.year-1 and its natural stands are widely replaced with plantations of Pinus patula. This replacement affects the most sensitive epiphyte communities. To track these conditions, lichens were examined on four trees of each phorophytic species. Each tree was divided into five vertical levels and bark roughness and acidity, as well as humidity and luminosity were measured at each level for each tree. The data were analysed by means of diversity indexes, Anova, and multidimensional scaling. 161 lichen fungal species were recorded, 53 of these unique to pine trees and 45 unique to oak trees. Cladonia ceratophylla and Herpothallon rubrocinctum stand out as a frequent species shared between both phorophytes, whereas Astrothelium spp, Anzia leucobatoides y Leptogium diaphanum are exclusive to oaks. Luminosity and bark roughness are factors influencing lichen community formation.

161-173

Authors: Mauricio Ponce-Donoso, Óscar Vallejos-Barra, Jorge Reyes de la Barra, Gustavo Daniluk-Mosquera, Ana Paula Coelho Duarte

Four methods of visual risk tree assessment were applied in 30 urban trees with different risk levels, in Talca city (Chile). The methods used were: “Avaliação de árvores de risco na arborização de vias públicas de Nova Olímpia” (Sampaio Method), “International Society of Arboriculture (ISA) Matheny & Clark” (Method ISA[A]), “Best Management Practice BMP/ISA” (Method ISA[B]) and “Urban tree risk management USDA Forest Service” (Method USF). The results were standardized for statistical analysis, finding significant differences and variations between the methods, after applying the nonparametric Kruskal-Wallis and Duncan test. Three groups were formed; the Sampaio and USF methods, which presented very high and high risk assessments, respectively; the second one was conformed by USF and ISA (A), which presented high to medium risk assessments; while the third group was shaped by ISA (B) with low risk assessments. Since the Talca city does not have its own methodology, it is suggested that the ISA (A) or USF method could be used in the Mediterranean area of Chile, because they were the methods presenting the best adaptation to local conditions.

188-204

Authors: David Mauricio Gómez Rodríguez, Julio Beltrán

The purpose of this study was to perform a dynamic modeling of demand and offer of ecosystem goods and services related to the land use change due to urban expansion in the Thomas van der Hammen reserve, in Bogotá, Colombia. Population growth, land use and impact on ecosystem goods and services changes were analyzed. The VensimPLE® software was used to develop the dynamic modeling. As results, it was noted that by 2060 the reserve will show loss, change or deterioration in 68.75% of the area that offers ecosystem goods and services if the actual change of land use rates is maintained. Furthermore, the population inside the reserve will be duplicated by period 2055-2056 with a possible loss of sub-superficial water used as ecosystem provision good and service. The relation between the city growth and the ecosystem goods and services deterioration was discussed.