title: Responses of primary production, leaf litter decomposition and associated communities to stream eutrophication.
abstract: We assessed the eutrophication effects on leaf litter decomposition and primary production, and on periphytic algae, fungi and invertebrates. According to the subsidy-stress model, we expected that when algae and decomposers were nutrient limited, their activity and diversity would increase at moderate levels of nutrient enrichment, but decrease at high levels of nutrients, because eutrophication would lead to the presence of other stressors and overwhelm the subsidy effect. Chestnut leaves (Castanea sativa Mill) were enclosed in mesh bags and immersed in five streams of the Ave River basin (northwest Portugal) to assess leaf decomposition and colonization by invertebrates and fungi. In parallel, polyethylene slides were attached to the mesh bags to allow colonization by algae and to assess primary production. Communities of periphytic algae and decomposers discriminated the streams according to the trophic state. Primary production decomposition and biodiversity were lower in streams at both ends of the trophic gradient.
authors: Graduate Program in Ecology of Continental Aquatic Environments, University of Maringá, Maringá, Paraná, Brazil. Electronic address: dunck.barbara@gmail.com.
authors: Bárbara
authors: B
authors: Dunck
authors: Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Braga, Portugal.
authors: Eva
authors: E
authors: Lima-Fernandes
authors: Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Braga, Portugal.
authors: Fernanda
authors: F
authors: Cássio
authors: Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB, University of Minho Pole), Department of Biology, University of Minho, Braga, Portugal.
authors: Ana
authors: A
authors: Cunha
authors: Graduate Program in Ecology of Continental Aquatic Environments, University of Maringá, Maringá, Paraná, Brazil; Department of General Biology and Center of Research in Limnology, Ichthyology and Aquaculture, University of Maringá, Brazil.
authors: Liliana
authors: L
authors: Rodrigues
authors: Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Braga, Portugal.
authors: Cláudia
authors: C
authors: Pascoal
mesh_terms: D000818:Animals; D044822:Biodiversity; D018533:Biomass; D000460:Chlorophyta / Q000254:growth & development; D004784:Environmental Monitoring; D005068:Eutrophication; D005658:Fungi / Q000254:growth & development; D007448:Invertebrates / Q000254:growth & development; D018515:Plant Leaves / Q000737:chemistry / Q000382:microbiology; D011174:Portugal; D025341:Principal Component Analysis; D045483:Rivers / Q000737:chemistry / Q000382:microbiology
keywords: Fungi; Invertebrates; Periphyton; Streams; Subsidy-stress model