Although Merostachys fischeriana is very abundant in the Brazilian Atlantic Rainforest, little attention has been paid to the biological interactions with other animals. The present study describes some of the interactions between ants and this bamboo species. The experiment was carried out in a fragment of a montane tropical forest in the Parque Estadual do Itacolomi, near Ouro Preto, MG, Brazil. Thirty culms of bamboo were randomly collected. The ants were obtained by direct collection from nodes and internodes. Morphometric variables of the bamboo were recorded for characterization of potential ant habitat. Merostachys fischeriana grows in rosettes as a thin bamboo (average = 1,0 cm; se = 0,27; n = 20) and is tall enough to reach the upper canopy of this low forest (average = 9,1 m; se = 2,72; n = 20). Fifteen ant species were sampled. Brachymyrmex heeri Forel was the most abundant in the nodes, while Camponotus crassus Mayr (Hymenoptera: Formicidae) was the most abundant in the internodes. The composition of the species that inhabit the internodes was different from the composition in the node (Q-test: Q = 3,76; P = 0,05). The level of occupation was defined by the number of holes (F = 10,33; P < 0,01), the number of internodes in the canopy (F = 6,84; P = 0,01) and the length of the culm (F = 7,52; P = 0,01). The plant's morphology allowed the occurrence of additional species of ants in the canopy and influenced the composition of the entire ant assemblage.

Vastas áreas do Brasil têm sido plantadas com eucaliptos, como fontes renováveis de madeira, carvão e celulose. Apesar do rápido crescimento e da produtividade de várias espécies de eucaliptos, aliviando, sem dúvida, a pressão por madeira de áreas nativas, existem custos ecológicos que devem ser considerados. Primeiramente, algumas espécies de eucaliptos são vulneráveis ao surgimento rápido de pragas. Um grande número de lepidópteros e coleópteros nativos, assim como de formigas cortadeiras, têm-se tornado pragas em eucaliptais plantados no Brasil. Provavelmente, a diversidade de mirtáceas da América do Sul suporta uma fauna que pode adaptar-se às espécies de eucaliptos introduzidas. Uma segunda consideração é o fato de que o litter de folhas (serrapilheira) produzido sob a plantação de eucaliptos difere substancialmente daquele de florestas nativas, tanto em termos de estrutura física, quanto química, criando uma série de problemas para a fauna de decompositores. Se a diversidade de micro-artrópodes é reduzida, o ciclo de nutrientes pode ser comprometido nos plantios de eucaliptos. Terceiro, a copa de florestas nativas suporta grande diversidade e biomassa de artrópodes, da qual dependem muitos pássaros, répteis e mamíferos, como alimento. Há evidências de que a biomassa e a diversidade de invertebrados são grandemente reduzidas em copas de plantações de eucaliptos exóticos. Isto, por sua vez, reduz a base de alimento, da qual dependem artrópodes e outros animais que vivem nas florestas, comprometendo o status de sua conservação. Este trabalho revisa as evidências dos efeitos ecológicos adversos das plantações brasileiras de eucaliptos e sugere caminhos pelos quais o Brasil pode atingir suas necessidades florestais, conservando os invertebrados e vertebrados que vivem nas mesmas e das quais elas dependem.

Vast areas of Brazil are being planted to Eucalyptus in order to provide renewable sources of timber, charcoal and cellulose. Although the rapid growth and productivity of various Eucalyptus species undoubtedly relaxes the pressure on logging of native forests, there are ecological costs. Firstly, some eucalypt species are vulnerable to pest outbreaks. A large number of native Lepidoptera, Coleoptera and leaf-cutting ants (Atta spp.), some of which have become pests, have been found on eucalypts growing in Brazil. Probably, the diverse myrtaceous flora of South America supports a fauna that can adapt to the introduced Eucalyptus species. Secondly, the leaf litter produced under Eucalyptus plantations differs substantially from that of native forests both in terms of its physical structure and chemistry, posing a range of problems for the native decomposer fauna. If microarthropod diversity is reduced, nutrient cycling could be impeded under eucalypt plantations. Thirdly, native forest canopies support a massive diversity and biomass of arthropods on which many birds, reptiles and mammals depend for food. The evidence is that invertebrate biomass and diversity are greatly reduced in the canopies of exotic eucalypt plantations. This, in turn, reduces the food-base on which forest arthropods and other animals depend, and hence their conservation status. This paper reviews the evidence for adverse ecological effects in Brazilian eucalypt plantations and suggests ways in which Brazil might meet its forestry needs, while conserving forest invertebrates and the vertebrates that depend on them.