Data/hora: 19/06/2024 14:53:17

Biblioteca(s): | Embrapa Pantanal.
Data corrente: | 10/01/1996
Data da última atualização: | 23/09/2013
Autoria: | GRANT, W. E.; FRENCH, N. R.
Título: | Evaluation of the role of small mammals in grassland ecosystems: a modeling approach.
Ano de publicação: | 1980
Fonte/Imprenta: | Ecological Modelling, v.8, p.15-37, Jan. 1980.
Idioma: | Inglês
Conteúdo: | Development of a grassland ecosystem simulation model quantifying mammal interaction with other ecosystem components indicates their influence on community structure and function. the approach has been to: (1) identify potential areas of small mammal interaction with system function; (2) quantify the interactions; (3) construct a model representing these interactions; (4) synthesize quantitative information on small mammal interactions with auxiliary information to obtain a mathematical representation of the major functional aspects of an ecosystem; and (5) simulate the ecosystem to estimate overall influence of small mammals. To facilitate the identification of potential influence, six small mammal functional groups and three major ecosystem components were specified. Small mammal groups include three feeding categories: (1) herbivore, (2) carnivore, and (3) granivore; and three behavioral categories: (1) soil mover, (2) food storer, and (3) builder. The three ecosystem components include: (1) abiotic, (2) primary producer, and (3) consumer - decomposer. A six by three matrix was formed with rows representing the six small mammal groups and columns representing the three ecosystem components. Each compartment of the matrix indicates potential influences of the small mammal group on the ecosystem component. Simulations indicate that two small mammal activities have greatest impact on  other ecosystem components. Upward translocation of soil has a significant positive effect on both percent bare surface soil and quantity of nitrogen in the top soil layer; and consumption of arthropods has a significant effect on arthroopod biomass dynamic. Even  with extremely high small mammal densities direct comsumption has an insignificant effect on primary production. based on indices quantifying total impact of small mammals, the hypothesis that grassland ecosystem structure can be fundamentally altered by changes in the small mammal community is tentatively rejected. Ecosystem function appaeras to be affected by relatively small fluctuations in small mammal density and by certain changes in composition of the small mammal community. Routes and rates of material flow within an ecosystem are influenced by small mammals, producing subtle but quantitative changes in ecosystem dynamics which are directly or indirectly a function of small mammal population dynamics. Therefore, the hypothesis that grassland ecosystem function is responsive to changes in the small mammal community cannot be rejected.
Palavras-Chave: | Community structure and function; Ecosystem; Estrutura de comunidade; Funcao; Grassland; Modelo simulado; Pequeno mamifero; Simulation model; Small mammal.
Thesagro: | Ecossistema; Pastagem.
Categoria do assunto: | --
Registro original: | Embrapa Pantanal (CPAP)
Exemplares: | CPAP - (30149-1) - ADD - SP - -- - SP1430 -  - 1430 - DIS