Influencia del uso de la tierra sobre almacenamiento de carbono en sistemas productivos y bosque primario en Napo, Reserva de Biosfera Sumaco, Ecuador

Abstract

A pesar de la creciente evidencia del efecto de los sistemas productivos tradicionales sobre el secuestro y almacenamiento de carbono, pocas investigaciones se han realizado para examinar esta relación entre el bosque y sistemas productivos tradicionales con base a la mitigación al cambio climático, especialmente en ecosistemas amazónicos. La presente investigación se realizó en la zona baja de Reserva de la Biosfera Sumaco, en la Provincia de Napo, Amazonía ecuatoriana. Se determinó el promedio de almacenamiento de Carbono (C) en la biomasa aérea y en el suelo, en siete sistemas de uso del suelo: Bosque primario, sistemas agroforestales tradicionales (chakras) con base al cultivo de cacao (sombra) propagados por semilla y por injertos, monocultivo de cacao propagado por semilla y por injertos y, chakras sin cacao con y sin sombra. Como resultado, de los sistemas agrícolas estudiados el sistema chakra con cacao propagado por semilla es el ecosistema productivo que almacena la mayor cantidad de C con un promedio de 141.4 Mg C ha-1, cantidad relativamente alta si se lo compara con el bosque primario que almacena un promedio de 334 Mg C ha-1 en la misma zona. El componente con mayor aporte al almacenamiento de carbono en el bosque es la biomasa viva con el 79.1% y, en los sistemas agrícolas el suelo con rangos de 48.9 a 90.2%.

Biodiversity and Carbon Sequestration in Chakra-Type Agroforestry Systems and Humid Tropical Forests of the Ecuadorian Amazon

“…It also presents an average annual rainfall of around 3000 mm. The relief of the region is made up of a series of medium hills that originate from the east-ern Andes, with a predominance of Entisol and Inceptisol order soils [24].…”

“…For this study, the total stored carbon (TSC) resulted from the sum of the following components: aboveground carbon (AGC), belowground root carbon (BGCr), litter biomass carbon (LBC), and soil organic carbon (SOC) [39]. However, this equation can be made up of more or fewer components according to the criteria and interest of the researchers [24,30,40,41]. TSC (Mg C ha −1 ) = AGC + BGCr + LBC + SOC (9) where TSC: total stored carbon in Mg C ha −1 ; and the Mg CO 2 ha −1 results from the product between the Mg C ha −1 and 3.67 which corresponds to the molecular weight of CO 2 .…”

“…The Mg C ha −1 of AGB and AGBCo are obtained and multiplied by 0.5, which is the carbon fraction (CF), proposed as a measure by the Intergovernmental Panel on Climate Change (IPCC) [24].…”

“…The biomass below the ground, provided by the roots, is obtained from the equation developed by [44], which was proposed by the IPCC in 2003 [24] and widely used by authors interested in knowing the biomass provided by the roots [24,30,39].…”

“…In AFSs, natural regeneration, perennial crops, as well as in forests, the soil represents the main carbon reserve [24], which is stored in different components and actively circulates between them. The main storage is found in tree biomass and soil [19], the vegetation incorporates atmospheric carbon into the biological carbon cycle, and the soil participates in its recycling and storage, as a result of the contribution of leaf litter, root exudates, microbial activity, stabilization, and leaching processes [7,19].…”