Ant community (Hymenoptera: Formicidae) associated with Callisthene fasciculata (Spr.) Mart. (Vochysiaceae) canopies in the Pantanal of Poconé, Mato Grosso, Brazil

ABSTRACT. Spiders are generalist predators and present a high diversity of capturing and foraging, as well as considerable species richness in tropical habitats. Although, generally, not presenting specifi c relations to the host plant, they can be infl uenced by its phenology, structure and resource availability. So, this study analyzed temporal variation on the structure and composition of Araneae assemblage in Callisthene fasciculata (Spr.) Mart. (Vochysiaceae) canopies, in an area of monodominant vegetation, in the periods of high water, receding water, dry season and rising water in Pantanal of Mato Grosso, Brazil. The collection was performed on 24 individuals of C. fasciculata, six in each seasonal period, in 2010 and 2011, making use of canopy fogging with insecticide. For that, ten nylon funnels were distributed under each canopy of C. fasciculata individuals, in a total of 240 m² of sampled canopies. In all, 3,610 spiders were collected and distributed in 24 families and 55 species. Anyphaenidae (43.3%; 6.5 ind./m 2 ), Pisauridae (16.2%; 2.4 ind./m 2 ), Araneidae (12.7%; 1.9 ind./m 2 ) and Salticidae (12.4%; 1.9 ind./m 2 ) were the most representative. Osoriella tahela Brescovit, 1998 was the most abundant species (12.2%). The nocturnal aerial runners of foliage (45.6%; 6.9 ind./m 2 ), nocturnal aerial ambushers of foliage (17.3%; 2.6 ind./m 2 ), aerial orb weavers (13.3%; 2.0 ind./m 2 ) and the diurnal aerial runners of foliage (12.5%; 1.9 ind./m 2 ) spiders represented the most abundant guilds. Signifi cant diff erences were observed in the composition of families and behavioral guilds, as well as abundance and richness among seasonal periods. The assemblage showed the highest abundance in receding water and highest species richness in high water period, probably related to the hydrologic cycle of the area and its infl uence on C. fasciculata phenology, indicating the importance of this plant species for spider's diversity maintenance in the Pantanal.KEYWORDS. Arthropods, biodiversity, nebulization, wetlands.RESUMO. Variação temporal na assembleia de aranhas (Arachnida, Araneae) em copas de Callisthene fasciculata (Vochysiaceae) no Pantanal brasileiro. Aranhas são predadoras, generalistas e apresentam elevada diversidade de estratégias de captura e forrageamento, bem como considerável riqueza de espécies em habitats tropicais. Apesar de, geralmente, não apresentarem relações específi cas com hospedeiros vegetais, suas assembleias podem ser infl uenciadas pela fenologia, estrutura e disponibilidade de recursos sobre o hospedeiro. Assim, este estudo analisou a variação temporal na estrutura e composição da assembleia de aranhas em copas de Callisthene fasciculata (Spr.) Mart. (Vochysiaceae) em área de vegetação monodominante, ao longo dos períodos de cheia, vazante, seca e enchente na região norte do Pantanal de Mato Grosso, Brasil. As coletas foram realizadas sobre 24 exemplares de C. fasciculata, seis em cada período sazonal, em 2010 e 2011, empregando-se a termonebulização de copas com inseticida. P...

Studies on arthropods associated with tropical rainforest canopies contribute to a further understanding of forest canopy community dynamics and their relationship to the structure and function of this ecosystem. This study evaluated arthropod community composition in monodominant Callisthene fasciculata forest canopy throughout the high water and dry periods in the northern region of the Pantanal in Mato Grosso, Brazil, as a part of a project about arboreal canopy arthropods associated with monodominant areas in this region. Sampling was conducted on 12 individuals of C. fasciculata, six from the high-water season (2010) and six from the dry season (2011), using insecticide fogging. A total of 28,197 arthropods were collected. Hymenoptera (the majority being Formicidae), Diptera, Acari, Thysanoptera, Hemiptera and Coleoptera, were the most representative groups. Although the analysis did not show variation in the abundance of individuals between the high water and dry seasons, the arthropod community varied significantly in taxa composition. Opiliones, Embioptera, Ephemeroptera and Scorpiones occurred only during the high-water period, with Polyxenida and Strepsiptera occurring only in the dry season. Thysanoptera was more abundant in the dry season, showing a relationship with the beginning of the C. fasciculata flowering period. In general, the high water and dry seasons maintain distinct communities in this habitat, illustrating how the temporal variation in the phenology of C. fasciculata imposed by the Pantanal’s hydrological regime alters the composition of the associated arthropod communities in the canopy of these monodominant formations in the Pantanal of Mato Grosso.

The study of coleopteran assemblages associated with the canopies of tropical forests can help to expand the knowledge about species diversity and the ecological patterns related to the distribution of this diversity in tropical environments, including wetlands such as the Brazilian Pantanal. In this scenario, the present study examined the effect of temporal variation on the abundance, richness and distribution of the Coleoptera assemblage associated with canopies of Callisthene fasciculata (Spr.) Mart. (Vochysiaceae) throughout the dry and high-water seasonal periods in the Northern Pantanal of Mato Grosso, Brazil. Twelve specimens of C. fasciculata were sampled between 2010 and 2011, six per seasonal period, by thermal fogging with insecticide. A total of 1,663 coleopterans were collected, consisting of 1,572 adults and 91 larvae. The adults are distributed into 38 families and 251 species or morphospecies. Chrysomelidae, Curculionidae, Nitidulidae and Tenebrionidae predominated in terms of abundance and richness. Family distribution, abundance, species richness and trophic guilds varied between the dry and high-water periods, demonstrating a relationship with the phenological conditions of C. fasciculata in addition to seasonality effect. In conclusion, the seasonality imposed by the hydrological regime and its influence on the phenology of C. fasciculata affect the structure of the coleopteran assemblage associated with the canopy of this monodominant vegetation formation in the Pantanal of Mato Grosso.

A sucessão ecológica depende da chuva de sementes. Embora a simples chegada de sementes não garanta o estabelecimento, conhecer a chuva de sementes é o primeiro passo para avaliar o processo sucessional em sítios sob restauração florestal. Por essa razão, foi amostrada a chuva de sementes em reflorestamento e em remanescente de floresta estacional semidecidual no sul do Brasil, a fim de descrever o processo. Em cada área, 18 armadilhas de sementes (1 m2) foram alocadas e visitadas, mensalmente, por dois anos. Todas as sementes amostradas foram identificadas, contadas e classificadas quanto à forma de vida, grupo ecológico e síndrome de dispersão. O remanescente florestal apresentou maior riqueza de espécies e abundância de propágulos que o reflorestamento. A composição de espécies também diferiu entre as áreas. A chuva de sementes, de ambas as áreas, apresentou maior proporção de árvores e de espécies intolerantes à sombra. Várias espécies não plantadas no reflorestamento, possivelmente dispersadas a partir do remanescente florestal, foram registradas no sítio em restauração. A análise dos resultados sugere que a chuva de semente não é um impedimento ao processo sucessional no reflorestamento. Entretanto, o sítio deve ser monitorado por mais tempo a fim de avaliar o estabelecimento, e não somente a chegada de sementes de espécies sucessionais tardias.