Apoyo en la investigación de los rasgos funcionales de Vallea stipularis y Quercus humboldtii asociados al carbono en tres zonas de Bogotá

Abstract

In Colombia, in the inventories of national GHG emissions carried out by IDEAM, an increasing trend has been identified, the sectors with the biggest participation are agriculture (38.1%) and energy (36.6%), respect to total national emissions they cover 75% of total emissions (Pulido, 2012). In Bogotá, the total emissions recorded correspond mainly to the transportation sector, which generates a contribution of 48% (Alcaldía Mayor de Bogotá, 2017). This brings with it consequences such as extreme temperatures and variation in rainfall, impact on the availability of drinking water, alteration of crops; and in biodiversity and ecosystem services due to the modification in behavior, as well as in the dispersion of plant and animal species of strategic ecosystems (IDIGER, 2023). In addition, the great impact of GHGs on global biodiversity is denoted; This is because the increase in atmospheric CO2 has an important effect on the physiological behavior of plants, since it regulates vital processes such as photosynthesis, respiration, metabolism, stomatal behavior, among other processes (Taiz & Zeiger, 2006). . Therefore, the purpose of this internship is to support the evaluation of the functional traits associated with carbon of two species in three areas of Bogotá with different anthropic intervention (Jardín Botánico de Bogotá José Celestino Mutis, the Reserva Umbral Cultural Horizontes and the Modelia neighborhoods and Hayuelos in the Fontibon town) to understand the responses of these plants to environmental filters. The species studied were the Raque (Vallea stipularis) of the Elaeocarpaceae family, and the Oak (Quercus humboldtii) of the Fagaceae family, because they are native species present in the urban trees of Bogotá and because they have ideal leaf characteristics for the measurement of functional traits. The traits were measured in five (5) individuals of the two (2) species in each of the three (3) selected sites; That is a total of 30 individuals measured (15 of each species). The functional traits evaluated were: Leaf area (AF) Specific leaf area (AFE) Leaf dry matter content (CFMS) Leaf thickness (EF) Stomatal density (DE), Stomata size (TE), Leaf area index (LAI) Leaf internal CO2 concentration (Ci) CO2 assimilation (A) Stomatal conductance (gs) Transpiration (E) Maximum photosynthesis (Amax) Dark respiration (Rd) Photosynthesis efficiency (ΦEfoto) and Wood Density (DM). The photosynthetic response to light (A/PAR) in Quercus humboldtii was higher in the Horizontes Cultural Threshold Reserve (1400 μmol(photons)m-2s-1) compared to the other sites, while in Vallea stipularis it was slightly higher (1900 μmol(photons)m-2s-1) in the streets of Fontibón in relation to the other sites. Regarding the traits of Quercus humboldtii, such as leaf area index, stomatal conductance, CO2 assimilation, transpiration and internal CO2 content, they did not show significant differences between the three locations evaluated, suggesting that these traits They are not plastic in this species. However, in Vallea stipularis, CO2 assimilation was lower in the Jardín Botánico (1.79 ± 0.75 μmol(CO2)m-2s-1), while the leaf area index was lower in the streets of Fontibón (0.33 ± 0.06) and the internal CO2 content was lower in the street (275 ± 42.55 μmol mol-1). Maximum photosynthesis for Quercus humboldtii was higher in the Jardín Botánico (7.21 μmol(CO2)m-2s-1) and lower in the Reserva Umbral Cultural Horizontes (3.26 μmol(CO2)m-2s-1). On the other hand, in Vallea stipularis, maximum photosynthesis was higher in the Reserva Umbral Cultural Horizontes (11.7 μmol(CO2)m-2s-1) and lower in the Jardín Botánico (8.21 μmol(CO2)m-2s-1). The SD was significantly higher for Q. humboldtii and V. stipularis individuals located in CLL with respect to individuals located in JBB. Similarly, the difference was also significantly greater for V. stipularis individuals located in CLL with respect to individuals located in RUH. The gs was higher in the V. stipularis individuals located in RUH and followed by the individuals located in the JBB; for Q. humboldtii the gs was higher for the individuals located in JBB and followed by the individuals located in RUH.