http://dx.doi.org/10.1590/1519-6984.17815 Original Article The impact of edge effect on termite community (Blattodea: Isoptera) in fragments of Brazilian Atlantic Rainforest C. S. Almeidaa,b, P. F. Cristaldob, D. F. Florencioc, E. J. M. Ribeirob, N. G. Cruza,b, E. A. Silvad, D. A. Costae and A. P. A. Araújob* aPrograma de Pós-graduação em Ecologia e Conservação, Universidade Federal de Sergipe – UFS, Av. Marechal Rondon, s/n, Jardim Rosa Elze, CEP 49100-000, São Cristóvão, SE, Brazil bLaboratório de Interações Ecológicas, Departamento de Ecologia, Universidade Federal de Sergipe – UFS, Av. Marechal Rondon, s/n, Jardim Rosa Elze, CEP 49100-000, São Cristóvão, SE, Brazil cDepartamento de Agrotecnologia e Ciências Sociais, Universidade Federal Rural do Semi-Árido – UFERSA, BR 110, Km 47, Bairro Pres. Costa e Silva, CP 137, CEP 59625-900, Mossoró, RN, Brazil dPrograma de Pós-graduação em Ciências Ambientais, Universidade Federal de Rondônia – UNIR, Av. Norte Sul, 7300, Bairro Nova Morada, CEP 76940-000, Rolim de Moura, RO, Brazil eDepartamento de Ciências Biológicas, Universidade do Estado de Mato Grosso – UNEMAT, Rod. MT. 358, Km 07, Jd. Aeroporto, CEP 78300-000, Tangará da Serra, MT, Brazil *e-mail: [email protected] Received: October 29, 2015 – Accepted: April 13, 2016 – Distributed: August 31, 2017 (With 1 figure) 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 Resumo A 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). Braz. J. Biol., 2017, vol. 77, no. 3, pp. 519-526 519 Almeida, C.S. et al. 1. Introduction fragmentation process on three fragments of Brazilian Atlantic Rainforest – “hotspot” of global biodiversity - Habitat fragmentation is one of the main anthropogenic regarded as one of the most threatened biome in the world threats leading to changes in biotic communities (Leidner et al., (Myers et al., 2000; Ribeiro et al., 2009). We tested the 2010). In general, habitat fragmentation is the process in hypotheses that (i) termite richness, abundance and their which continuous areas are subdivided in isolated and smaller activity in the sampled area have a positive relationship remnants (Souza et al., 2001). Area reduction from habitat with vegetation structure and resource availability, (ii) such fragmentation enhances edge effects - characterized by an measures of termite species community decrease in the increase in the incidence of light, temperature, winds and forest edge compared with interior of fragments and a reduction of humidity (Laurance, 2004). This process (iii) termite species composition (β diversity) is altered changes vegetational structure and microclimate conditions between forest edge and interior. between forest edge and interior affecting directly the communities structure of animals (e.g. Maciel et al., 2003; 2. Material and Methods Laurance, 2004) as well as indirectly through changes in the activity and behaviour of predator’s species. A range 2.1. Study site of distinct taxonomic group has been shown to be affected Fieldwork was conducted on three fragments (Table 1) by habitat fragmentation or edge effect (Klein, 1989; of Atlantic Rainforest located in the state of Sergipe, Pinheiro et al., 2010; Penido et al., 2015). Northeastern, Brazil. The landscape consists mainly The losses of species and populations have been of a semi-deciduous forest with secondary remnants suggested to promote a decline in the ecosystem processes (Santos et al., 2007). Fragments of the Brazilian Atlantic with effect on a global scale (see Dirzo et al., 2014). In a Rainforest (“Mata Atlântica”) are reported as a priority long-term, effects of habitat disturbance could promote area for biodiversity conservation (“hotspot”) (Myers et al., modifications in the ecosystem processes (Dambros et al., 2000) and an important area of endemism with only 2% 2013). Termites are known to act directly in the ecosystem of the original forest area (Silva and Tabarelli, 2000). process through changes in the physical and chemical 2.2. Sampling design structure of soil as well as in the microbial activity and organic matter decomposition (Bignell and Eggleton, 2000; Termite community and habitat structure were sampled Holt and Lepage, 2000). The activity of termites on soil from December 2013 to January 2014 (“dry season”). indirectly allows the establishment and maintenance of other In each fragment and locality (forest edge and interior) species at a local scale (Redford, 1984; Pringle et al., 2010; two distinct methodologies were used: (i) quadrants and Beaudrot et al., 2011), make them “ecosystem engineers” (ii) transect (as described below). In quadrants, sampling (see Jones et al., 1994). was performed to assess the termite richness, their activity Termite species have been shown to be responsive in the sampled area and soil litter biomass. In transects, sampling was carried out to assess the termite abundance to environmental disturbance (Souza and Brown, 1994; and vegetational structure. Davies, 2002; Luke et al., 2014). However, mechanisms Forest edge sites were delimited up to 5 m. after the in which habitat fragmentation alters the community begging of vegetation in all sampled fragments. Forest structure of these insects are still poorly studied. Termites interior sites were 100 m. for the smallest fragment (Mata are soft-body insects in which temperature and humid do Campus Rural - MCR) and 150 m. for the larger ones affect their distribution and diversity (Cancello et al., (Mata do Crasto - MC and Mata do Junco - MJ) (Table 1). 2014). Thus, alteration of vegetational structure and microclimate conditions in edge areas may decrease 2.2.1. Termite community resource availability and nesting sites promoting strong To examine the edge effect of habitat fragmentation effects on termite communities. In fact, the abundance of on termite species richness and their activity in the area, termite nests has been shown to decrease in forest edge termites were collected in 16 quadrants (5 m × 2 m) in compared with interior (Axelsson and Andersson, 2012). each one of the fragments (eight at the forest edge and In the present study, we analyzed whether termite eight at the forest interior), totalizing 48 quadrants and community is affected by the edge effects of habitat 480 m2 of sampled area. Each quadrant was at least 20 m Table 1. Overview of fragments sampled in the present study with their respective area (ha), locality and geographic coordinates. Forest code Forest name Area (ha) Locality Latitude Longitude Santa Luzia do MC Mata do Castro 900 11° 22’ 37° 25’ Ithanhy Refugio da Vida MJ 766 Capela 10° 46’ 37° 01’ Silvestre Mata do Junco Campus Rural da MCR Universidade Federal 1 São Cristovão 11° 01’ 37° 12’ de Sergipe 520 Braz. J. Biol., 2017, vol. 77, no. 3, pp. 519-526 The