Abstract
The soil fauna has an important role in the processes of organic matter decomposition,
nutrient cycles, soil aeration and fertility. Thus, studies about the composition and structures
of these communities are important, considering also the scarcity of information in different
regions of the country, mainly in relation to the Pantanal of Mato Grosso. This study was
carried out in Pirizal, in the municipal district of Nossa Senhora do Livramento, Retiro Novo
ranch, Pantanal of Poconé - Mato Grosso, in the areas of cambarazal, where the plant specie
Vochysia divergens Pohl. (Vochysiaceae) predominates. This study had as its objectives to
gather knowledge on the composition, diversity, abundance and distribution of the arthropod
community in soil and litter, collected through the Winkler extractor during the seasonal
periods (flood, ebb, dry and rain) of this region in order to assess the influence of the hydro
regime on this community. This method consists of the demarcation of quadrants (1m²), not
exceeding 10 squares per collection to fill 10 nylon bags of litter and 10 of soil. In laboratory,
these bags containing soil and litter were put into the Winkler funnels, and suspended to an
environment with controlled temperature for the desiccation of the sampled material and
consequent extraction of the arthropods. Those were separated and identified to order
taxonomic level and the Coleoptera individuals were further identified to the family and
morphospecies levels. During the four seasonal periods 97746 arthropods were obtained.
(2572,26 individuals/m2), distributed into the Arachnida, Insecta, Diplopoda, Chilopoda and
Crustacea classes and 24 taxonomic orders. Acari (72,5%; 110,59 individuals /m2),
Hymenoptera, being most of it Formicidae (8,6%; 141,9 individuals/m2), Collembola (8,4%;
138,8 individuals/m2) and Coleoptera (3,5%; 57,3 individuals/m2), were the dominant groups
in the litter. In the soil, Acari (64,1%; 596,1 individuals/m2), Collembola (16,5%; 153,2
individuals/m2), Coleoptera (6,9%; 64,5 individuals/m2) and Hymenoptera, most of it
Formicidae (4,8%; 44,8 individuals/m2), were the most abundant. 3822 Coleoptera individuals
were sampled and distributed into 28 families and 357 morphospecies. The most abundant
families were Scarabaeidae (1012 individuals; 25%), Staphylinidae (920 individuals; 24,1%)
and Ptiliidae (728 individuals; 19%). The Staphylinidae represented the most diversified
family with 71 morphospecies followed by Pselaphidae (32) and Ptiliidae (24). In relation to
the seasonality, the highest abundance of arthropods was obtained during the drought period,
followed by rain, flood and ebb.
