title: Land Use Influences Niche Size and the Assimilation of Resources by Benthic Macroinvertebrates in Tropical Headwater Streams.
abstract: It is well recognized that assemblage structure of stream macroinvertebrates changes with alterations in catchment or local land use. Our objective was to understand how the trophic ecology of benthic macroinvertebrate assemblages responds to land use changes in tropical streams. We used the isotope methodology to assess how energy flow and trophic relations among macroinvertebrates were affected in environments affected by different land uses (natural cover, pasture, sugar cane plantation). Macroinvertebrates were sampled and categorized into functional feeding groups, and available trophic resources were sampled and evaluated for the isotopic composition of 13C and 15N along streams located in the Cerrado (neotropical savanna). Streams altered by pasture or sugar cane had wider and more overlapped trophic niches, which corresponded to more generalist feeding habits. In contrast, trophic groups in streams with native vegetation had narrower trophic niches with smaller overlaps, suggesting greater specialization. Pasture sites had greater ranges of resources exploited, indicating higher trophic diversity than sites with natural cover and sugar cane plantation. We conclude that agricultural land uses appears to alter the food base and shift macroinvertebrate assemblages towards more generalist feeding behaviors and greater overlap of the trophic niches.
authors.affiliation: Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Biologia Geral, Laboratório de Ecologia de Bentos, Belo Horizonte, MG, Brasil.
authors.forename: Diego Marcel
authors.initials: DM
authors.lastname: Parreira de Castro
authors.affiliation: Universidade Federal de Lavras, Departamento de Biologia, Setor de Ecologia, Laboratório de Ecologia de Peixes, Lavras, MG, Brasil.
authors.forename: Débora
authors.initials: D
authors.lastname: Reis de Carvalho
authors.affiliation: Universidade Federal de Lavras, Departamento de Biologia, Setor de Ecologia, Laboratório de Ecologia de Peixes, Lavras, MG, Brasil.
authors.forename: Paulo dos Santos
authors.initials: Pdos S
authors.lastname: Pompeu
authors.affiliation: Universidade de São Paulo, Centro de Energia Nuclear na Agricultura-CENA, Laboratório de Ecologia Isotópica, Piracicaba, SP, Brasil.
authors.forename: Marcelo Zacharias
authors.initials: MZ
authors.lastname: Moreira
authors.affiliation: Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Ecologia, Brasília, DF, Brasil.
authors.forename: Gabriela Bielefeld
authors.initials: GB
authors.lastname: Nardoto
authors.affiliation: Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Biologia Geral, Laboratório de Ecologia de Bentos, Belo Horizonte, MG, Brasil.
authors.forename: Marcos
authors.initials: M
authors.lastname: Callisto
mesh_terms: D000383:Agriculture / Q000379:methods; D000818:Animals; D044822:Biodiversity; D001938:Brazil; D002247:Carbon Isotopes / Q000032:analysis; D003247:Conservation of Natural Resources; D017753:Ecosystem; D005247:Feeding Behavior; D007448:Invertebrates / Q000145:classification / Q000502:physiology; D009587:Nitrogen Isotopes / Q000032:analysis; D045483:Rivers / Q000737:chemistry; D014329:Tropical Climate
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes