Estimated carbon dioxide exchange for three native species in an ecological reserve of Mexico City

Capture and emission of carbon dioxide of three species (Buddleia cordata, Senecio praecox and Echeveria gibbiflora) in the Reserva Ecológica del Pedregal de San Ángel (Ecological Reserve of the Pedregal de San Ángel), were estimated. CO2 sampling was carried out in 2010 during the dry (February, March, April and November) and rainy seasons (July to October). On the dry season B. cordata and S. praecox captured 16.14 and 3.25 kg CO2, respectively, whereas E. gibbiflora emitted 45.76 kg CO2. In the rainy season the exchange of CO2 was different for the three species. In the dry season, the photosynthetic rate was 22 μmol CO2 m-2 s-1 for B. cordata, 27 μmolCO2 m-2 s-1 for S. praecox and 29 μmolCO2 m-2 s-1 for E. gibbiflora. In the rainy season they were 6, 5.25 and 3 μmol CO2 m-2 s-1, respectively. In addition, MODIS data were used to estimate the normalized difference vegetation index (NDVI), indicating that the intensity of greenery at the site increased during the rainy months. This paper explains the contribution of studied plants to the carbon cycle of an ecosystem located within an urban area, and the relationship of environmental variables such as temperature, density photosynthetic photon flux and relative humidity in the capture or emission of CO2. This work provides valuable information about the carbon cycle dynamics on urban ecosystems, which can be useful in future studies for climate change mitigation.