Comparing Biogenic Volatile Organic Compounds fluxes between two different biomes, the Amazon and the Atlantic tropical forests.

Abstract:

Biogenic Volatile Organic Compounds (BVOCs) emitted mainly by vegetation influence the Earth's hydrological cycles in biosphere-atmosphere interactions, that is, influencing precipitation. The Amazon is the largest remaining untouched forest area in the world, this ecosystem emits large quantities of BVOCs, on regional and global scales. Land use in the Amazon region is proportional to climate change, that is, changes in VOC emissions are due to the biosphere-atmosphere mechanism (Yañez - serrano, 2020.). Another biome with only 7% of the original area is the Atlantic Forest, which extends along the Brazilian coast to Paraguay and Argentina. It is known that the two forests are connected by “flying rivers”, movements of large amounts of water vapor transported by the atmosphere of the Amazon Basin to the south of South America. Therefore, it is extremely important to quantify the BVOC fluxes of the two forests. BVOCs were measured by the Relaxed Eddy Accumulation method (REA) at the Amazon Tall Tower Observatory (ATTO), located 150 km northeast of Manaus and in the Immigrants Ecological Park (PEI) in the Atlantic Forest 40 km southeast of São Paulo, Brazil. The measurement period occurred in the dry and rainy seasons of 2019, during the daytime profile just above the canopy. Air sampling was performed by an automatic home device for the analysis of differential flows of BVOCs by REA method with Tenax TA and Carbograph® sorbent cartridges (Kesselmeier, 2002). The samples were analyzed by gas chromatography (GC) with thermal desorption coupled to a time-of-flight mass spectrometer (TD-GC-TOF-MS, Markes International). The GC uses b-cyclodextrin columns to obtain the separation of enantiomeric molecules. The fluxes found were mostly positive throughout the day, that is, more emissions. The most concentrated BVOCs found were in the Amazon (+) a-pinene and in the Atlantic the (+) limonene. Therefore, we can conclude a great difference between the type of BVOCs in each region, stating that this distinction is due to the large industrial zone in the southeast and south of the country, in comparison to the pristine region of the Amazon, in addition to that we must emphasize a greater investigation on adequate land use and the climatic relationship between macro and micro scale, since it is directly correlated to the climate.