The impact of edge effect on termite community (Blattodea: Isoptera) in fragments of Brazilian Atlantic Rainforest

Abstract

Habitat fragmentation is considered to be one of the biggest threats to tropical ecosystem functioning. In this region, termites perform an important ecological role as decomposers and ecosystem engineers. In the present study, we tested whether termite community is negatively affected by edge effects on three fragments of Brazilian Atlantic Rainforest. Termite abundance and vegetation structure were sampled in 10 transects (15 × 2 m), while termite richness, activity, and soil litter biomass were measured in 16 quadrants (5 × 2 m) at forest edge and interior of each fragment. Habitat structure (i.e. number of tree, diameter at breast height and soil litter biomass) did not differ between forest edge and interior of fragments. Termite richness, abundance and activity were not affected by edge effect. However, differences were observed in the β diversity between forest edge and interior as well as in the fragments sampled. The β diversity partitioning indicates that species turnover is the determinant process of termite community composition under edge effect. Our results suggest that conservation strategies should be based on the selection of several distinct sites instead of few rich sites (e.g. nesting).Keywords: β diversity, habitat fragmentation, Termitoidea, species turnover.O impacto do efeito de borda na comunidade de cupins (Blattodea: Isoptera) em fragmentos de florestas da Mata Atlântica ResumoA fragmentação do habitat é considerada uma das maiores ameaças para o funcionamento do ecossistema tropical. Nesta região, os cupins desempenham um papel ecológico importante como decompositores e engenheiros do ecossistema. No presente estudo, testamos se comunidades de cupins são negativamente afetadas pelo efeito de borda em três fragmentos de Mata Atlântica. Para isso, foram amostrados a abundância de cupins e a estrutura da vegetação em 10 transectos (15 × 2 m), enquanto a riqueza, abundância de cupins e biomassa da serrapilheira foram amostrados em 16 parcelas (5 × 2 m) na borda e no interior de cada um dos três fragmentos. A estrutura do habitat (número de árvores, diâmetro à altura do peito e biomassa da serrapilheira) não diferiu entre a borda e o interior dos fragmentos. A riqueza, abundância e atividade dos cupins também não foram afetados pelo efeito de borda. No entanto, foram observadas diferenças na diversidade β entre borda e interior dos fragmentos, bem como nos fragmentos amostrados. O particionamento da diversidade β indicou que a substituição de espécies ("turnover") é o processo determinante da composição da comunidade de cupins sob efeito de borda. Nossos resultados sugerem que as estratégias de conservação devem ser baseadas na seleção de locais distintos em vez de poucos locais (via processo de aninhamento -"nesting").Palavras-chave: diversidade β, fragmentação de habitat, Termitoidea, substituição de espécies (turnover).

Termite (Isoptera) Diversity in a Gallery Forests Relict in the Colombian Eastern Plains

“…Our results are similar to recent observations in some Brazilian forest fragments (Oliveira et al, 2013;Almeida et al, 2016), in which termite diversity is not directly explained by the structural/environmental variables of the vegetation included in those studies. Besides vegetation structure and environmental conditions, understanding termite plasticity and habitat requirements as well as quality and availability of food (Kirton et al,.…”

“…Besides vegetation structure and environmental conditions, understanding termite plasticity and habitat requirements as well as quality and availability of food (Kirton et al,. 1999;Araujo et al, 2011;Almeida et al, 2016) or predation (Dambros et al, 2016) may contribute to better explain termite diversity association in these particular habitats.…”

“…Therefore, their diversity may serve as an indicator of conservation status, for example in forest fragments (Alves et al, 2011, Oliveira et al, 2013, Almeida et al, 2016. Termites are the most abundant organisms in the soil macrofauna of natural ecosystems and semi-cultivated and cultivated areas in the Eastern Plains of Colombia, where they can form more than 50% of the total abundance (Decaëns et al, 1994;Lavelle et al, 2014).…”