Produtividade primária fitoplanctônica submetida a diferentes qualidades espectrais da luz
Nenhuma Miniatura disponível
Data
2020-03-03
Autores
Oliveira, Fabricio Bronzoni de
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal do Espírito Santo
Resumo
Knowledge about the primary productivity process is of fundamental importance for understanding the metabolism and energy dynamics in natural ecosystems. Thus, the present study aimed to analyze the effects of three wavelength bands (blue, green and red), on the primary productivity of the phytoplankton community in the UFES lagoon, at Goiabeiras campus, Vitória (ES). The experiment was performed in triplicate (n=3), using the light and dark flasks method, with the light filters being applied to the light flasks. Transparent filter and control treatment (without filter application) were also used. The sampling frequency was monthly, in an annual cycle, in the central area of the lagoon. The primary productivity was assessed by the Winkler method and the data were expressed in mgO2.L-1.h-1. The phytoplankton community was evaluated in relation to richness, density, biovolume, frequency of occurrence, abundant and dominant taxa and biomass was evaluated based on chlorophyll a, b and c concentrations. The principal component analysis was applied for temporal ordering of the. The Spearman correlation was applied between the values of gross (GPP) and net (NPP) primary productivity and the algal biovolume and the differences among treatments was evaluated by the Kruskall-Wallis test (p<0.05). The principal component analysis did not show seasonality for the studied environment. The phytoplankton community was composed of 43 taxa and five classes, with Cyanobacteria being the most prominent (24 taxa), followed by Chlorophyceae (15 taxa). Cyanobacteria showed higher density and biovolume, sometimes reaching 100% of the total density and biovolume. The highest average values of primary productivity were recorded in the red light range, for both GPP and NPP, being statistically higher than the values recorded for the blue and green light range. The increase in primary productivity in the red range was positively correlated with the Cyanobacteria biovolume. Our results showed evidence that red light range is the most efficient for increasing primary productivity in a community dominated by Cyanobacteria.
Descrição
Palavras-chave
Comprimentos de onda , Radiação luminosa , Produção de oxigênio