Artigo

Leaf-litter breakdown in urban streams of Central Amazonia: Direct and indirect effects of physical, chemical, and biological factors

Urbanization alters water physical and chemical variables and may affect leaf-litter breakdown in streams. Higher temperature and nutrient inputs in urban streams can stimulate microbial biomass, which can increase leaflitter breakdown rates over rates in nonurban streams. On the other hand, urbaniz...

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Autor principal: Martins, Renato Tavares
Outros Autores: Melo, Adriano Sanches, Gonçalves, José Francisco Júnior, Hamada, Neusa
Grau: Artigo
Idioma: English
Publicado em: Freshwater Science 2020
Assuntos:
Decomposition
Ecosystem Function
Environmental Factor
Fungus
Invertebrate
Leaf Litter
Microorganism
Stream
Urbanization
Amazonia
Coussapoa
Fungi
Invertebrata
Mabea
Acesso em linha: https://repositorio.inpa.gov.br/handle/1/17481
id oai:repositorio:1-17481
recordtype dspace
spelling oai:repositorio:1-17481 Leaf-litter breakdown in urban streams of Central Amazonia: Direct and indirect effects of physical, chemical, and biological factors Martins, Renato Tavares Melo, Adriano Sanches Gonçalves, José Francisco Júnior Hamada, Neusa Decomposition Ecosystem Function Environmental Factor Fungus Invertebrate Leaf Litter Microorganism Stream Urbanization Amazonia Coussapoa Fungi Invertebrata Mabea Urbanization alters water physical and chemical variables and may affect leaf-litter breakdown in streams. Higher temperature and nutrient inputs in urban streams can stimulate microbial biomass, which can increase leaflitter breakdown rates over rates in nonurban streams. On the other hand, urbanization can reduce leaf-litter breakdown rates by eliminating shredders. We evaluated physical, chemical, and biological factors that may directly and indirectly affect leaf-litter breakdown of Coussapoa trinervia and Mabea speciosa in 42 urban streams in Central Amazonia. We used structural equation modeling to assess whether: 1) shredder activity is more important than microbes for leaf-litter breakdown of plant species with softer tissues, 2) microbes (as adenosine triphosphate [ATP] concentration) and fungi (as ergosterol concentration) positively influence leaf-litter breakdown rate, 3) water velocity positively affects leaf-litter breakdown rate, and 4) effects of shredders and microbes, including fungi, on leaf-litter breakdown are mediated by the effects of urbanization. Leaf-litter breakdown of M. speciosa and C. trinervia was fastest in the least urbanized streams. Fungi had a direct positive effect on leaf-litter breakdown of both species, but shredders were the most important factor for leaf-litter breakdown in M. speciosa (softer leaf tissues). Water velocity had a slight indirect effect on leaf-litter breakdown of C. trinervia through its effect on fungi. Microbes were not important for leaf-litter breakdown rates of either species. Urbanization indirectly affected leaf-litter breakdown via negative effects on shredder and fungal biomass. Our study provides evidence for multiple direct and indirect pathways by which urbanization can decrease leaf-litter breakdown rates in tropical streams, mainly through negative effects on the fungal and shredder biomass. © 2015 by The Society for Freshwater Science. 2020-06-15T21:43:24Z 2020-06-15T21:43:24Z 2015 Artigo https://repositorio.inpa.gov.br/handle/1/17481 10.1086/681086 en Volume 34, Número 2, Pags. 716-726 Restrito Freshwater Science
institution Instituto Nacional de Pesquisas da Amazônia - Repositório Institucional
collection INPA-RI
language English
topic Decomposition
Ecosystem Function
Environmental Factor
Fungus
Invertebrate
Leaf Litter
Microorganism
Stream
Urbanization
Amazonia
Coussapoa
Fungi
Invertebrata
Mabea
spellingShingle Decomposition
Ecosystem Function
Environmental Factor
Fungus
Invertebrate
Leaf Litter
Microorganism
Stream
Urbanization
Amazonia
Coussapoa
Fungi
Invertebrata
Mabea
Martins, Renato Tavares
Leaf-litter breakdown in urban streams of Central Amazonia: Direct and indirect effects of physical, chemical, and biological factors
topic_facet Decomposition
Ecosystem Function
Environmental Factor
Fungus
Invertebrate
Leaf Litter
Microorganism
Stream
Urbanization
Amazonia
Coussapoa
Fungi
Invertebrata
Mabea
description Urbanization alters water physical and chemical variables and may affect leaf-litter breakdown in streams. Higher temperature and nutrient inputs in urban streams can stimulate microbial biomass, which can increase leaflitter breakdown rates over rates in nonurban streams. On the other hand, urbanization can reduce leaf-litter breakdown rates by eliminating shredders. We evaluated physical, chemical, and biological factors that may directly and indirectly affect leaf-litter breakdown of Coussapoa trinervia and Mabea speciosa in 42 urban streams in Central Amazonia. We used structural equation modeling to assess whether: 1) shredder activity is more important than microbes for leaf-litter breakdown of plant species with softer tissues, 2) microbes (as adenosine triphosphate [ATP] concentration) and fungi (as ergosterol concentration) positively influence leaf-litter breakdown rate, 3) water velocity positively affects leaf-litter breakdown rate, and 4) effects of shredders and microbes, including fungi, on leaf-litter breakdown are mediated by the effects of urbanization. Leaf-litter breakdown of M. speciosa and C. trinervia was fastest in the least urbanized streams. Fungi had a direct positive effect on leaf-litter breakdown of both species, but shredders were the most important factor for leaf-litter breakdown in M. speciosa (softer leaf tissues). Water velocity had a slight indirect effect on leaf-litter breakdown of C. trinervia through its effect on fungi. Microbes were not important for leaf-litter breakdown rates of either species. Urbanization indirectly affected leaf-litter breakdown via negative effects on shredder and fungal biomass. Our study provides evidence for multiple direct and indirect pathways by which urbanization can decrease leaf-litter breakdown rates in tropical streams, mainly through negative effects on the fungal and shredder biomass. © 2015 by The Society for Freshwater Science.
format Artigo
author Martins, Renato Tavares
author2 Melo, Adriano Sanches
Gonçalves, José Francisco Júnior
Hamada, Neusa
author2Str Melo, Adriano Sanches
Gonçalves, José Francisco Júnior
Hamada, Neusa
title Leaf-litter breakdown in urban streams of Central Amazonia: Direct and indirect effects of physical, chemical, and biological factors
title_short Leaf-litter breakdown in urban streams of Central Amazonia: Direct and indirect effects of physical, chemical, and biological factors
title_full Leaf-litter breakdown in urban streams of Central Amazonia: Direct and indirect effects of physical, chemical, and biological factors
title_fullStr Leaf-litter breakdown in urban streams of Central Amazonia: Direct and indirect effects of physical, chemical, and biological factors
title_full_unstemmed Leaf-litter breakdown in urban streams of Central Amazonia: Direct and indirect effects of physical, chemical, and biological factors
title_sort leaf-litter breakdown in urban streams of central amazonia: direct and indirect effects of physical, chemical, and biological factors
publisher Freshwater Science
publishDate 2020
url https://repositorio.inpa.gov.br/handle/1/17481
_version_ 1787141930729078784
score 11.755432

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