DIVERSITY OF ANTS (HYMENOPTERA: FORMICIDAE) OF LITTER IN DIFFERENT SYSTEMS OF SOIL USE

Neste trabalho s\ue3o listadas as esp\ue9cies de formigas de serrapilheira encontradas em quatro ambientes localizados na regi\ue3o noroeste do estado do Rio Grande do Sul, a fim de verificar o impacto da a\ue7\ue3o antr\uf3pica realizada no meio rural. Para a coleta das formigas da serrapilheira foi utilizado o m\ue9todo do extrator de Winkler. Foram coletados 6.300 esp\ue9cimes pertencentes a oito subfam\uedlias, 18 tribos, 31 g\ueaneros e 108 esp\ue9cies. A floresta nativa possui a maior riqueza observada com 90 esp\ue9cies coletadas, seguida por eucalipto com 65 esp\ue9cies, agricultura e pastagem ex\uf3tica com 20 esp\ue9cies cada. O \uedndice de diversidade de Margalef foi de 11,21 para \ue1rea com floresta nativa, 8,37 para eucalipto, 3,48 para agricultura e, 2,71 na \ue1rea de pastagem ex\uf3tica. O \uedndice de diversidade de Shannon obtido foi de 2,89; 3,15; 2,43 e 1,98 e de equitabilidade 0,64; 0,75; 0,84 e 0,66 para as \ue1reas com: floresta nativa, eucalipto, agricultura e pastagem, respectivamente. O maior valor do \uedndice de diversidade para a \ue1rea de eucalipto pode ser devido \ue0 \ue1rea possuir 28 anos de implanta\ue7\ue3o, sem ter sido manejada, com sub-bosque de esp\ue9cies nativas, formando um dossel cont\uednuo e espessa camada de serrapilheira, j\ue1 a floresta nativa por sofrer interven\ue7\uf5es antr\uf3picas, possui um valor de diversidade de Shannon menor comparado \ue0 \ue1rea com eucalipto.Litter ant species found in four sites located in northwestern Rio Grande do Sul state were listed in this study to verify the impact of human activities conducted in rural areas. The method used for the collection of litter ants was the Winkler extractor. There were collected 6,300 specimens belonging to eight subfamilies, 18 tribes, 31 genera and 108 species. Native forest presented the highest richness observed with 90 species collected, followed by 65 eucalyptus species, and agriculture and pasture with 20 exotic species each. Margalef\u2019s diversity index was 11.21 for area with native forest, 8.37 for eucalypt, 3.48 for agriculture, and 2.71 in exotic pasture area. The Shannon\u2019s diversity indices obtained were 2.89, 3.15, 2.43 and 1.98 and equitability indices of 0.64, 0.75, 0.84 and 0.66 for areas with native forest, eucalyptus, agriculture and exotic pasture, respectively. The highest diversity index for the eucalypt area may be due to the age of the forest (28 years) and the fact that it has not been managed as well as due to the presence of understory of native species, forming a continuous canopy and thick litter layer. On the other hand, since the native forest has suffered human interventions, it has a lower Shannon\u2019s diversity index compared to the eucalypt area