Uso de imágenes aéreas de alta resolución para la detección de cambios en el almacén de carbono en biomasa aérea en comunidades semiáridas, tras la introducción de la especie exótica Cenchrus ciliaris

Background: The alteration of the carbon reservoir stored in vegetation, imply the modification of biogeochemical cycles. The change of land use and cover (CUCS) is one of the main drivers for these alterations. As a consequence of the primary activities occurring in arid/semiarid lands, carbon reservoirs are continually modified. The limited information and heterogeneity of these environments increase the uncertainty regarding the effects on carbon dynamics consequence of CUCS. The development of new methodological approaches, such as the incorporation of aerial high-resolution RGB (red/green/blue) imagery analyses, will allow extensive and continuous monitoring of carbon in arid zones. Questions: Is it possible to estimate aboveground carbon stock using RGB images obtained by Unmanned Aerial Vehicles? Site and years of study: Subtropical scrub and buffel grassland communities, located in the central Sonora, Mexico. August-October 2019 and 2020. Methods: a) In situ woody vegetation censuses were carried out to estimate carbon stock in aerial biomass (ACBA) using allometric equations (direct method), b) ACBA was calculated, using allometric equations and vegetation metrics obtained from aerial RGB images. Results: The introduction of buffel grassland implies the reduction of woody individuals, therefor, a decrease in ACBA. In total, the scrub contains 10.35 Mg C/ha, and buffel grassland around 3.20 Mg C/ha. There are correlation and significance between direct and indirect methods. Conclusions: Establishing buffel grassland reduces the ACBA, up to 70 %. The use of RGB images allowed us to estimate ACBA in arid zones.