title: A new index for assessing the value of importance of species--VIS.
abstract: Phytosociological analysis in native forests is performed considering the horizontal and vertical structure of the studied population, whose most expressive parameters are the density, dominance, frequency, value of coverage and value of importance of species. Many phytosociological studies include a value of importance of species calculated by adding density, dominance and frequency, in their relative forms, however, this estimator is a mathematical impropriety because the result is a sum of indexes and does not express the true meaning of species' value. This is because the estimator is still influenced predominantly by the density of occurrence of species and cannot capture the relevant hierarchical participation of emerging species that occur with low density in the biocoenosis. In this work, we propose a new index to characterize the value of importance of species based on the hierarchy and spatial absolute probability of the species in the biocoenosis, illustrated with data from a forest fragment of semideciduous tropical forest located in Cassia, MG, Brazil. The new index appropriately expressed the importance of species in the evaluated fragment.
authors.affiliation: Departamento de Engenharia Florestal, Universidade Federal do Paraná, Curitiba, PR, Brazil.
authors.forename: Sylvio Péllico
authors.initials: SP
authors.lastname: Netto
authors.affiliation: Departamento de Matemática, Universidade Tecnológica Federal do Paraná, Curitiba, PR, Brazil.
authors.forename: Mauricio K
authors.initials: MK
authors.lastname: Amaral
authors.affiliation: Escola de Ciências Agrárias e Medicina Veterinária, Pontifícia Universidade Católica do Paraná, São José dos Pinhais, PR, Brazil.
authors.forename: Marcio
authors.initials: M
authors.lastname: Coraiola
mesh_terms: D044822:Biodiversity; D001938:Brazil; D064308:Ecological Parameter Monitoring / Q000379:methods*; D065928:Forests; D008954:Models, Biological; D011156:Population Density; D013045:Species Specificity; D014329:Tropical Climate