Resumo
A Mata Atlântica, segundo maior bioma da América do Sul, é formada por um conjunto de fitofisionomias que compõem o Domínio Mata Atlântica. Como reflexo da ocupação territorial e da exploração desordenada, tornou-se uma das formações mais descaracterizadas atualmente, sendo representada por fragmentos isolados que não ultrapassam 8% de sua cobertura original (SOS Mata Atlântica 2009).[...]
Resumo
The composition and abundance fluctuations of Oligoryzomys nigripes (Olfers, 1818), Akodon montensis Thomas, 1913, Delomys dorsalis (Hensel, 1872) and Oryzomys angouya Fisher, 1814 were studied from August 1992 to August 1993 in two areas of mixed forest with conifers at National Forest of São Francisco de Paula (2923S, 5023W), southern Brazil. Seven bimestrial trappings were carried out in each study area. Two grids of 60 traps were exposed simultaneously during five nights in each trapping period. The highest abundance indexes occurred in August 1992 and August 1993, just on the final stage of seed production by Araucaria angustifolia. Such observations, more evident for O. nigripes and A. montensis, point out that populations of these species increased when there were many A. angustifolia seeds on the floor. The high abundance indexes exhibited by A. montensis in August 1992 and August 1993 can be explained by recruitment. D. dorsalis seems to be the most habitat selective species because of the low abundance indexes that were found in the area with high densitiesof A. angustifolia. O. angouya was recorded occasionallyand always in low levels of abundance in both study areas. The presence of these species, in spite of low abundance indexes, during the stage of seed production by A. angustifolia in the forest, points out that resource availability indeed increases at this
Resumo
The composition and abundance fluctuations of Oligoryzomys nigripes (Olfers, 1818), Akodon montensis Thomas, 1913, Delomys dorsalis (Hensel, 1872) and Oryzomys angouya Fisher, 1814 were studied from August 1992 to August 1993 in two areas of mixed forest with conifers at National Forest of São Francisco de Paula (2923S, 5023W), southern Brazil. Seven bimestrial trappings were carried out in each study area. Two grids of 60 traps were exposed simultaneously during five nights in each trapping period. The highest abundance indexes occurred in August 1992 and August 1993, just on the final stage of seed production by Araucaria angustifolia. Such observations, more evident for O. nigripes and A. montensis, point out that populations of these species increased when there were many A. angustifolia seeds on the floor. The high abundance indexes exhibited by A. montensis in August 1992 and August 1993 can be explained by recruitment. D. dorsalis seems to be the most habitat selective species because of the low abundance indexes that were found in the area with high densitiesof A. angustifolia. O. angouya was recorded occasionallyand always in low levels of abundance in both study areas. The presence of these species, in spite of low abundance indexes, during the stage of seed production by A. angustifolia in the forest, points out that resource availability indeed increases at this
Resumo
Marshlands are preferential reproduction places and refuge for many species of animals and plants. The marshes of the coastal plains of Rio Grande do Sul State, Brazil, have been modified by agricultural activities and increasing urbanization. The ecological importance of a private marshland situated in Viamão City (3005S, 5047W), Rio Grande do Sul State, to local fauna, was evaluated to guide the owners in the preservation of the ecosystem. Monthly, we did samples of vertebrate species (a total of 45) to estimate their numbers and their seasonal fluctuations in the area. There were significant differences in the frequencies of some abundant species that were related to their feeding, reproduction or displacement habths. Macrophytes and grasses offer good places to nest and protection of Gallinula chloropus (Linnaeus,1758), Vanellus chilensis (Gmelin, 1782), Jacana jacana (Linnaeus,1758), Podiceps major (Boddaert,1783), Podilymbus podiceps (Linnaeus,1758) (Aves) and Myocastorcoypus (Molina, 1782) (Mammalia). The preservation of the studied marshland in a periurban area is important to maintain the local and migratory fauna.
Resumo
Marshlands are preferential reproduction places and refuge for many species of animals and plants. The marshes of the coastal plains of Rio Grande do Sul State, Brazil, have been modified by agricultural activities and increasing urbanization. The ecological importance of a private marshland situated in Viamão City (3005S, 5047W), Rio Grande do Sul State, to local fauna, was evaluated to guide the owners in the preservation of the ecosystem. Monthly, we did samples of vertebrate species (a total of 45) to estimate their numbers and their seasonal fluctuations in the area. There were significant differences in the frequencies of some abundant species that were related to their feeding, reproduction or displacement habths. Macrophytes and grasses offer good places to nest and protection of Gallinula chloropus (Linnaeus,1758), Vanellus chilensis (Gmelin, 1782), Jacana jacana (Linnaeus,1758), Podiceps major (Boddaert,1783), Podilymbus podiceps (Linnaeus,1758) (Aves) and Myocastorcoypus (Molina, 1782) (Mammalia). The preservation of the studied marshland in a periurban area is important to maintain the local and migratory fauna.
Resumo
A Mata Atlântica, segundo maior bioma da América do Sul, é formada por um conjunto de fitofisionomias que compõem o Domínio Mata Atlântica. Como reflexo da ocupação territorial e da exploração desordenada, tornou-se uma das formações mais descaracterizadas atualmente, sendo representada por fragmentos isolados que não ultrapassam 8% de sua cobertura original (SOS Mata Atlântica 2009).[...]