The Aquatic Communities Inhabiting Internodes of Two Sympatric Bamboos in Argentinean Subtropical Forest

Abstract

In order to determine if phytotelmata in sympatric bamboos of the genus Guadua might be colonized by different types of arthropods and contain communities of different complexities, the following objectives were formulated: (1) to analyze the structure and species richness of the aquatic macroinvertebrate communities, (2) to comparatively analyze co-occurrences; and (3) to identify the main predators. Field studies were conducted in a subtropical forest in Argentina, where 80 water-filled bamboo internodes of Guadua chacoensis (Rojas Acosta) Londoño and Peterson (Poales: Poaceae) and G. trinii (Nees) Nees and Rupr. were sampled. Morphological measurements indicated that G. chacoensis held more fluid than G. trinii. The communities differed between Guadua species, but many macroinvertebrate species used both bamboo species. The phytotelmata were mainly colonized by Diptera of the families Culicidae and Ceratopogonidae.

Phytotelmata colonization in bamboo (Guadua sp.) culms in northeast Argentina

“…The top predators in internodes and stumps were the larvae of Toxorhynchites, each individual using a container. Similar observations were made during a previous study in the Paranaense forest, located in the northwest of Misiones province (Campos 2013). The presence of a single larva of Toxorhynchites per container could be due to the cannibalism and killing behaviour that is typical of species of this genus.…”

“…Hence, there are large holes allowing the entry of larger organisms, such as small vertebrates. In contrast, Campos (2013) noted that the holes of the bamboos Guadua trinii and Guadua chacoensis, whose walls are thick (about 2-3 cm) and hard, are of small diameter (about 5 mm), which limits the entry of vertebrates and large arthropods. Furthermore, regardless of hole size, a decrease in the number of species becomes extreme in the southernmost area of the forest.…”

“…One 5-mm diameter hole was made in the middle of the internode wall to facilitate colonization by insects. The size was chosen because according to a previous study this is the most frequent size of the holes in nature (Campos 2013). The holes were oriented in different directions but this was not considered as a variable in the present study.…”

“…The best studied taxon, because of its medical importance, is Culicidae; but we are far from having a complete record of species that use this type of microhabitat as a breeding site. In the Neotropical region, approximately 72 species of culicid found in bamboo have been reported, of which 54 have been identified and 18 remain unidentified (Davis 1944;Louton et al 1996;Lozovei 1998Lozovei , 2001Campos 2013).…”

Biting midges (Diptera: Ceratopogonidae) from an urban forest fragment in Central Amazon (Brazil): Effects of opening areas on abundance, richness, and composition

“…In general, there is a positive relationship between invertebrate fauna (abundance and richness) and volume in phytotelmata (Schmidl et al 2008, Jabiol et al 2009, Campos 2013, Dézerald et al 2014. However, water volume has a higher influence on the abundance of invertebrates in environments with frequent droughts, mainly due to egg dehydration and larval mortality (Yanoviak 1999a, Paradise 2004).…”