The value of primary, secondary and plantation forests for fruit‐feeding butterflies in the Brazilian Amazon

Abstract

Summary1. Secondary forests growing on cleared lands and tree plantations are becoming increasingly widespread land-uses in the tropics. Previous studies are divided on the conservation importance of these habitats for tropical forest butterflies. 2. We use a robust sampling design, accounting for both seasonality and vertical stratification, to examine fruit-feeding butterflies (Nymphalidae) in patches of secondary forest and Eucalyptus plantation 2-3 orders of magnitude larger than those previously sampled. 3. We recorded 10 587 butterflies and 128 species in 3200 trap-days. Species richness was highest in primary forest and lowest in plantations, while butterfly abundance showed the opposite response. All habitats were distinct in terms of community structure. 4. There was a significant interaction between habitat and season based on richness and abundance metrics, although not based on community structure. Secondary forest exhibited higher observed richness than primary forest in the peak of the dry-season, but not at other times of the year. This observation could explain the lack of consensus in previous studies, as those reporting higher richness in secondary forest only sampled during the dry-season. 5. In general, habitat quality appeared to be more important than the surrounding landscape in determining butterfly community structure. However, the community structure of the strong-flying Charaxinae was related to the amount of primary forest in surrounding landscape. There was very poor congruence between the response patterns of richness and abundance among different butterfly subfamilies. 6. Linear regressions between resource availability and butterfly abundance showed a strong influence of leaf phenology in both primary and secondary forest, but no influence of fruit phenology. 7. Synthesis and applications : A lack of seasonal replication and small sampling sizes may have led previous studies to over-emphasize the conservation importance of secondary forest and plantations for butterflies. We show that these habitats are significantly poorer than primary forest in terms of number of species, and hold distinct butterfly communities. Although quantifying the number of species restricted to primary forest remains difficult, these results cast doubt on the presumption that secondary habitats will provide refuge for many of the species being lost through deforestation. We therefore strongly urge measures that prioritize the conservation of remaining primary forests where they still exist.

Species diversity and community structure of fruit-feeding butterflies (Lepidoptera: Nymphalidae) in an eastern amazonian forest

“…For this reason, methods of extrapolation are essential to help us estimate species richness more accurately, since they are supposedly independent of sample sizes (Magurran, 2004). Considering that our observed richness was similar to the estimated richness values, we believe that sample biases were not the main drivers of the differences recorded between our study and those from Barlow et al (2007), Ribeiro et al (2012), and Ramos (2000), for example. Also, we consider that other factors that could potentially increase our observed richness, such as sampling in the forest canopy (Devries & Walla, 2001;Fermon et al, 2005), would not significantly change the number of sampled species, since canopy height at SAG rarely exceeds 15 m even in the most preserved sites.…”

“…However, the observed richness is considerably lower than the richness found in other areas of the Brazilian Amazon. For example, Barlow et al (2007) recorded 128 species in a study area between the states of Pará and Amapá, and Ribeiro et al (2012) collected 68 species in the state of Amazonas. Respecting the eastern Amazon, little information on fruit-feeding butterfly diversity have been published, especially for the state of Maranhão (Martins et al, 2017).…”

“…A major concern is the most endangered endemism center in Brazil, the Belém Center of Endemism, located in the eastern Amazon between the states of Pará and Maranhão (Silva et al, 2005). There is a growing need for studies performed in habitat patches of the eastern Amazonian forest, since these remaining habitats may contribute to partially offset biodiversity losses (Barlow et al, 2007;Tulloch et al, 2016).…”

“…Among this group, fruit-feeding butterflies have been widely used as bioindicators because of their sensitivity to environmental modifications (Brown Jr. & Freitas, 2000;Fermon et al, 2005;Barlow et al, 2007;Uehara-Prado et al, 2007). This guild feeds on rotten fruits, plant exudates, carcasses, and mammal excrement (Devries, 1987;Devries et al, 1997;Freitas et al, 2014), and it includes four Nymphalidae subfamilies (Biblidinae, Satyrinae, Charaxinae and Nymphalinae [only the tribe Coeini]) (Wahlberg et al, 2009).…”

Quantifying the biodiversity value of tropical primary, secondary, and plantation forests

“…First, many biodiversity studies are either poorly replicated or conducted in very small plots that are vulnerable to edge effects from adjacent primary forest (11,12) and may systematically over-estimate the value of secondary and plantation forests for forest biodiversity (11,13,14). Second, our understanding of the value of these habitats for different taxa is incomplete because of a research bias toward certain groups of vertebrates and pristine habitats (15), which is exacerbated by studies reporting low levels of congruence between taxa along gradients of forest degradation (16)(17)(18).…”