Estructura, Biomasa a\'erea y carbono almacenado en los bosques del Sur y Noroccidente de c\'ordoba

We estimated the aerial biomass and stored carbon in twelve types of forests in the department of Córdoba with annual rain fall ranging from 3000 mm (super humid climates) to 1300 mm (semihumid climate). Biomass was estimated based on structural aspects of the vegetation (diameter at breast height, total height, and wood specific weight). We tested nine allometric equations for tropical forests available in the literature and selected those proposed by Chave et al (2005) that are specific for humid and dry forests. Carbon content in trees was measured in four tissues (stem, branch, bark, and leafs) through an automated dry combustion method, which estimates the percentage of carbon in a sample of known weight. To quantify the stored carbon in the biomass, such percentages of carbon per dry mass were multiplied by the biomass estimated for each tissue; the stored carbon for each individual was then estimated by adding the biomass value of each tissue. Highest biomass and carbon values were found in the associations Prestoeo decurrentis Trichillietum poeppigi, Macrolobio ischnocalycis Peltogynetum purpurea (biomass 40.83 41.15 Mg/0.05 ha; carbon 18.4418.9 MgC/0.05ha), followed by forests of the associations Protio aracouchini Viroletum elongatae and Tovomito weddellianae Quercetum humboldtii (biomass 30.01-34.33 Mg/0.05 ha; carbon 13.78-15.76 MgC/0.05 ha). The lowest values were found in forests of the associations Marilo laxiflorae Pentaclethretum macrolobae, Mayno grandifoliae Astrocaryetum malybo, Cordietum proctato – panamensis, and the community Acalypha sp. and Guazuma ulmifolia (biomass 7.39-14.09 Mg/0.05 ha; carbon 3.346.58 MgC/0.05 ha). Such results are related with the low values in basal area and height as well as the tendency of having a high number of individuals within these forests. In most forests, biomass and carbon are concentrated in the arboreal strata (superior and inferior) and in individuals with a diameter greater than 70 cm, such as the forests of the associations Prestoeo decurrentisTrichillietum poeppigi, Macrolobio ischnocalycis-Peltogynetum purpurea, and Trichilio hirtaeSchizolobietum parahibi_1. In contrast, the association Cordietum proctato – panamensis and the community Acalypha sp. and Guazuma ulmifolia have the greatest accumulated biomass (57.91% and 62.71%, respectively) in the subarboreal stratum with individuals of smaller diameter (diametric Classes II and III with 10-20cm and 30-50cm in diameter), which is related with their low values in biomass and carbon. Biomass and carbon varied with precipitation, ranging from 34.18 Mg/0.05 ha and 15.68 MgC/0.05 ha, respectively, in super humid forests to 7.39 Mg/0.05 ha and 3.34 MgC/0.05 ha in semi-humid forests; similar values were found in very humid (biomass 21.15 Mg/0.05 ha; carbon 9.27 MgC/0.05 ha) to humid forests (biomass 21.4 Mg/0.05; carbon 9.64 MgC/0.05 ha). It is possible that in addition to precipitation, the conservation state of each forest also affects these values because disturbance increases with an increment in the climatic conditions, from the very humid to semi-humid. The species contribution to the biomass and carbon are not equal, with most carbon stored in the biomass of a reduced number of species. Among those species are Quercus humboldtii with 18.86 Mg/0.05 ha (62.99%) of biomass and 8.68 MgC/0.05 ha (62.93%) of carbon; Cavanillesia platanifolia with 8.36 Mg/0.05 ha (34.74%) of biomass and 3.78 (34.88%) MgC/0.05 ha of carbon; Peltogyne purpurea with15.57 Mg/0.05ha (37.88%) of biomass and 7.11 MgC/0.05ha (37.61%) of carbon; and Dipteryx oleifera with 7.97 Mg/0.05 ha (23.25%) of biomass and 3.76 MgC/0.05 ha (23.99%) of carbon.