Colombia Forestal

9

Authors: Mauricio Ponce-Donoso, Osca Vallejos Barra, Pablo Heinrich, Ursula Doll

Dendrometric variables such as DAP and height are used to manage forests, especially when the species is endemic and threatened. Nothofagus glauca (Hualo) presents these characteristics, requiring research to guide its sustainable management. The objective of this article is adjust functions that quantify the total leaf area (TLA) and total leaf biomass (TLB) in specimens of a relict forest located in Maule Region (Chile), allowing to monitor this species. In plots of 100 m2, BDH and height of all trees were measured, 16 specimens were removed, extracting the total leaves to determine their fresh mass. With samples of 50 leaves per tree, the fresh and dry mass were obtained, determining the leaf area with LI-COR LI-3100. Using regressions, statistical significance was obtained with a basal area, which its determination coefficients varied between 63.80 and 93.27 %, with standard errors of 8.46 m2 and 0.58 kg for TLA and TLB, respectively. The estimate of the leaf area index (LAI) was 0.32 m2.m-2, while for leaf biomass it was 2.1 ton.ha-1.

11

Authors: Camila Pizano, Ph.D., Juan Carlos Cárdenas Salgado

Fire is a recurring, but poorly studied disturbance in tropical dry forests, where seeds are the main source of regeneration. In this study, we measured seed germination of eight Colombian dry forest tree species under elevated temperature treatments that simulated fires of low (100°C) and high intensity (200°C) with different exposure times (5 and 15 minutes). We found that the factor that best explained seed germination was temperature, while time was not significant. Seven species germinated similarly under the treatment of 100°C and under the control, while seed germination under 200°C was almost null. These results suggest that the seeds of some dry forest species have tolerance to moderate fires, however, most seeds would perish under high intensity of fires.

14

Authors: Bayron Alexander Ruiz Blandon, Efrén Hernández Álvarez, Eduardo Salcedo Pérez, Ramón Rodríguez Macías, Agustín Gallegos Rodríguez, Eduardo Valdés Velarde, Rufo Sánchez Hernández

Teak is an exotic plant introduced to Mexico for its wood value. The aim of this study was to quantify the carbon stored in the plant biomass and soil and to determine the wood lignocellulosic composition in 6-years-old teak plantations in the Nayarit state, Mexico. In three plantations, dendrometric and biomass information were collected from 75 trees, as well as litter layer and soil to determine their properties. The differences were significant (p≤0.0001) when comparing the plantation with the highest and lowest growth in DBH (54 %), height (51.3 %) and basal area (78.7 %) being the soils with the best pH (6.2); as well as, the aerial biomass yield (59.4 %), teak carbon (60.2 %), litter layer (30.3 %) and soil (41.9 %) per surface, without differences in lignocellular contents. It is recommended to study the roots and soil nutrients, since they condition the teak efficiency regarding the climate change.

17

Authors: Kristian David Rubiano Calderón

Cities show particular environmental characteristics that give rise to phenomena such as heat islands. Although vegetation covers are key in mitigating these adverse conditions, their distribution has been found to be inequitable. Analyzing this distribution and the supply of ecosystem services is important for the city planning . For this reason, the distribution of the thermal regulation capacity of the public vegetation covers of Bogotá city was analyzed, using tree coverage and greenness as proxy variables, through geostatistical analysis, Geographic Information Systems and remote sensing. There was an increase in the average greenness of the parks according to their size and the socioeconomic stratum where they are located, the tree coverage increased in the highest strata. Coldspots and hotspots of these variables and the thermal regulation potential were identified in the areas with the lowest and highest strata, respectively.

9

Authors: leif Armando Portal Cahuana, João Vicente Figueiredo Latorraca, José Henrique Camargo Pace, Glaycianne Christine Vieira dos Santos, Dayane Oliveira Lima, Letícia Maria Alves Ramos, Jair Figueiredo Do Carmo

There are few studies related with X-ray micro-densitometry regarding wood from native tropical forests. The objective of this study was to determine the radial variation of the apparent density of the Amburana cearensis wood by X-ray micro-densitometry. Indeed, eleven trees were selected, in which radial sections were cut from the pith to the cortex, in order to determine the apparent density and the anatomical characteristic in three radial positions. The results showed that the wood of A. cearensis presented mean values of wood density, minimum and maximum of 0.16 and 0.87 g.cm-3 respectively. Moreover, the wood showed significant difference in three positions of the pith, (intermediate and cortex), and this difference can be explained by the microscopic anatomy, especially with the vessels (diameter, area and number.mm-2). X-ray micro-densitometry is an important tool in the radial evaluation of wood and can help in the definition of the growth rings’ limits of A. cearensis.

11

Authors: María del Pilar Arroyave Maya, Martha Isabel Posada Posada, David J Nowak, Robert E Hoehn

Urban forests provide different ecosystem services including air pollution removal, carbon storage and sequestration, microclimate and water regulation, and habitat for wildlife. This results in the improvement of environmental quality and population’s welfare. In this study, we evaluated the urban forest structure in the Aburra Valley, and quantified and valuated the pollutant removal by urban trees using the “i-Tree” Eco software. We established 398 plots for forest sampling, and used secondary information about climatic conditions and air pollution. Results reveal that there is 23% of tree coverage in the study area, and a pollutant removal of 228 tons per year (2.1 million USD value approximately). Finally, we recommended strategies to optimize the pollutant removal by the urban forest and to create mechanisms for compensation of tree cover loss.

16

Authors: Darwin Leonel Moreno Echeverry, Diana Carolina Useche Rodríguez, Helber Enrique Balaguera López

The global warming effects in urban areas make preponderant the study of tree species at different conditions of abiotic stress, such as waterlogging. Therefore, it is important to conduct research to select species tolerating these environmental conditions and to find physiological markers for these selection processes. In this study, we analyzed the physiological behavior of six native species with four levels of waterlogging, determining the hydric state, the photosynthetic behavior and loss of electrolytes. According to the parameters evaluated, it is recommended to establish Quercus humboldtii and Ficus. tequendamae in areas with high rainfall and with a tendency to waterlogging. This recommendation arises due to the evident tolerance, allowing these areas in Bogota to maintain urban trees under climate change scenarios. The stability of the cell membranes and the maximum photosynthetic efficiency of photosystem II can be used as markers for tolerance under waterlogging conditions in trees.