Salt Marshes Buffer El Niño Effects on Benthic Secondary Production
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Data
2021
Tipo de documento
Dissertação
Título da Revista
ISSN da Revista
Título de Volume
Área do conhecimento
Ciências Agrárias
Modalidade de acesso
Acesso aberto
Editora
Autores
Stipp, Mateus Floriano
Orientador
Netto, Sérgio Antonio
Coorientador
Resumo
O El Niño-Oscilação Sul (ENOS) influencia fortemente o clima e a hidrologia do planeta, consequentemente, a estrutura e funcionamento das comunidades biológicas estuarinas. No entanto, os efeitos do ENOS nas áreas costeiras são dependentes da escala espacial e das características intrínsecas do estuário, como seus diferentes habitats. Durante seis anos (2013 a 2018) investigamos a variabilidade interanual da produção secundária macrobêntica de marismas de Spartina alterniflora e áreas não-vegetadas adjacentes em uma lagoa costeira subtropical no sul do Brasil e testamos se os eventos ENOS (El Niño e La Niña) afetam de forma semelhante a produção secundária bêntica desses dois habitats. Nossos resultados mostram que a produção secundária da macrofauna variou ao longo do tempo, apresentando um aumento relacionado a ocorrência do evento El Niño 2015/2016 e consequente aumento na precipitação. No entanto, as marismas responderam de forma diferente das áreas não-vegetadas, com uma produção secundária mais estável. Há também uma distinção nos efeitos sobre diferentes táxons. Embora as espécies mais representativas, Laeonereis acuta e Monokalliapseudes schubarti, tenham apresentado aumento na produção secundária em áreas não-vegetadas, L. acuta apresentou aumento apenas na biomassa, enquanto para M. schubarti houve aumento na biomassa e densidade. Em contraste, ambas as espécies apresentaram densidade, biomassa e produção secundária sem diferenças significativas ao longo do tempo nas marismas. Esses achados reforçam que as variações climáticas podem influenciar a produção secundária, mas as marismas têm um efeito tampão sobre a influência do El Niño nas associações bênticas.
The El Niño-Southern Oscillation (ENSO) strongly influences the planet climate and hydrology, consequently, the structure and functioning of estuarine biological communities. However, the effects of the ENSO on coastal areas are dependent of the spatial scale and the intrinsic characteristics of the estuary, such as different habitats. During six years (2013 to 2018) we investigate the interannual variability of macrobenthic secondary production of Spartina alterniflora marshes and adjacent unvegetated areas in a subtropical coastal lagoon in Southern Brazil and we tested whether the ENSO events (El Niño and La Niña) affect similarly the benthic secondary production of these two habitats. Our results show that the secondary production of benthic macrofauna varied over time, showing an increase related to the occurrence of the El Niño 2015/2016 event and consequent increase in precipitation. However, the salt marshes responded differently of the unvegetated areas, with a secondary production more stable. There is also a distinction in the effects on different taxa. Although the most representative macrobenthic species, Laeonereis acuta and Monokalliapseudes schubarti, increased secondary production in unvegetated areas, L. acuta showed an increase only in biomass, whereas for M. schubarti there was an increase in biomass and density. In contrast, both species showed density, biomass and secondary production with no significant differences over time in the salt marshes. These findings reinforce that climatic variations can influence secondary production, but the salt marshes have a buffering effect on the influence of El Niño on benthic associations.
The El Niño-Southern Oscillation (ENSO) strongly influences the planet climate and hydrology, consequently, the structure and functioning of estuarine biological communities. However, the effects of the ENSO on coastal areas are dependent of the spatial scale and the intrinsic characteristics of the estuary, such as different habitats. During six years (2013 to 2018) we investigate the interannual variability of macrobenthic secondary production of Spartina alterniflora marshes and adjacent unvegetated areas in a subtropical coastal lagoon in Southern Brazil and we tested whether the ENSO events (El Niño and La Niña) affect similarly the benthic secondary production of these two habitats. Our results show that the secondary production of benthic macrofauna varied over time, showing an increase related to the occurrence of the El Niño 2015/2016 event and consequent increase in precipitation. However, the salt marshes responded differently of the unvegetated areas, with a secondary production more stable. There is also a distinction in the effects on different taxa. Although the most representative macrobenthic species, Laeonereis acuta and Monokalliapseudes schubarti, increased secondary production in unvegetated areas, L. acuta showed an increase only in biomass, whereas for M. schubarti there was an increase in biomass and density. In contrast, both species showed density, biomass and secondary production with no significant differences over time in the salt marshes. These findings reinforce that climatic variations can influence secondary production, but the salt marshes have a buffering effect on the influence of El Niño on benthic associations.
Palavras-chave
Climate variability, Estuarine communities, Habitat complexity, Long-term variability, Productivity, Salt marshes