Estudo comparativo do incremento do carbono azul armazenado pelas ervas marinhas abaixo e acima do substrato nas zonas entre- marés e na franja (sublitoral) a noroeste da cidade de Maputo

Abstract

The study of the increase in blue carbon captured by seagrasses in different areas northwest of the city of Maputo was carried out between November 10 and 13, 2021. Sampling was carried out at sixty (60) points in six areas in two zones in Bairro dos Pescadores, during low tide of spring tides, in places whose depth did not exceed 1 meter in height. Sampling consisted of recording the coordinates of points in the seagrass beds using a GPS and collecting seagrass samples by making two transects within the beds. During the study carried out in the Bairro dos pescadors in the different collection areas, it was possible to verify six (6) species: Cymodocea serrulata, Halodule uninervis, Halophila ovalis, Thalassia hemprichii, Thalassodendron cilliatum and Zostera capensis. Cymodocea serrulata, Halophila ovalis and Halodule uninervis are the most commonly distributed species and some are associated with each other along the beach. On average, two to three species of seagrass occur per meadow, with monospecific meadows consisting of Cymodocea serrulat a. The aim of this study was to assess blue carbon (BC) stocks in biomass and sediment in seagrass meadow habitats. Nine sediment samples from 10 m apart per seagrass bed were collected at six sites (three from each area). Six replicates for biomass from each area were harvested at each location over four days. Organic carbon stocks varied among species and reservoirs, with mean seagrass carbon stocks in the two zones (intertidal and fringe (sublittoral)) above and below ground (0.21 ± 0.008 Mg C and 0.23 ± 0.0009 Mg C) and (0.16 ± 0.006 Mg C and 0.18 ± 0.0007 Mg C) respectively. The difference in aboveground biomass between the two zones is due to differences in species characteristics, which affect photosynthesis rates, productivity and biomass accumulation. Sediment was the dominant C reservoir in the fringe zone with 0.7 ± 0.002 Mg C (TRADUÇÃO NOSSA)