Atlantic Forest Of Northeastern Brazil Research Articles

Floristic inventory of a zone of ecological tension in the Atlantic Forest of Northeastern Brazil

Abstract The Serra de Itabaiana National Park, Sergipe, is situated in a transition area between Atlantic Forest and the Caatinga and is considered by the Ministério do Meio Ambiente to be extremely important for the conservation of the Atlantic Forest flora. The paucity of floristic information from Sergipe state and areas of ecological tension motivated this floristic survey in the only National Park in the state. Botanical collections were made from 2006 to 2009, in six expedictions, by means of random walking. A total of 552 species distributed in 99 families of angiosperms and one gymnosperm were found. Of the species collected, 187 occurred in shrubby-herbaceous, 304 in shrubby, and 247 in arborescent physiognomy, with 23 common to all physiognomies. Leguminosae (41 spp.), Cyperaceae (40 spp.), Poaceae (38 spp.), Orchidaceae (30 spp.), Euphorbiaceae (27 spp.), Rubiaceae (24 spp.), Melastomataceae (21 spp.) and Bromeliaceae (20 spp.) were the richest families. The study revealed the presence of species in common with the Caatinga, Cerrado, Seasonal Forest, campo rupestre, restinga, tabuleiro and areas of ecological tension, corroborating floristically the classification of the locality as an area of ecological tension and reasserting its importance for the conservation of biodiversity.

Effects of Pioneer Tree Species Hyperabundance on Forest Fragments in Northeastern Brazil

Despite many studies on fragmentation of tropical forests, the extent to which plant and animal communities are altered in small, isolated forest fragments remains obscure if not controversial. We examined the hypothesis that fragmentation alters the relative abundance of tree species with different vegetative and reproductive traits. In a fragmented landscape (670 km(2) ) of the Atlantic Forest of northeastern Brazil, we categorized 4056 trees of 182 species by leafing pattern, reproductive phenology, and morphology of seeds and fruit. We calculated relative abundance of traits in 50 1-ha plots in three types of forest configurations: forest edges, small forest fragments (3.4-83.6 ha), and interior of the largest forest fragment (3500 ha, old growth). Although evergreen species were the most abundant across all configurations, forest edges and small fragments had more deciduous and semideciduous species than interior forest. Edges lacked supra-annual flowering and fruiting species and had more species and stems with drupes and small seeds than small forest fragments and forest interior areas. In an ordination of species similarity and life-history traits, the three types of configurations formed clearly segregated clusters. Furthermore, the differences in the taxonomic and functional (i.e., trait-based) composition of tree assemblages we documented were driven primarily by the higher abundance of pioneer species in the forest edge and small forest fragments. Our work provides strong evidence that long-term transitions in phenology and seed and fruit morphology of tree functional groups are occurring in fragmented tropical forests. Our results also suggest that edge-induced shifts in tree assemblages of tropical forests can be larger than previously documented.

Edge-induced narrowing of dietary diversity in leaf-cutting ants

Much of the ecological alteration faced by human-modified Neotropical forests can be assigned to edge effects, including the proliferation of some voracious herbivores such as leaf-cutting ants. However, the underlying mechanisms/impacts of tropical forest edge on herbivores performance and their foraging behaviour (e.g. dietary diversity) have rarely been investigated. The goal of this study was, therefore, to determine whether and how the annual diet (i.e. species richness, diversity and the relative proportion of pioneer versus non-pioneer species of plant materials) of Atta cephalotes colonies differs in the forest edge versus the interior zone of a large remnant of Atlantic forest in northeastern Brazil. Among the key results was a strong habitat effect on dietary diversity (explaining ca. 40-50% of the variation), which, in edge colonies, decreased approximately by one fourth compared to interior colonies (inverse of Simpson's index: 3.7±0.84 versus 4.99±0.95). There was a predominance of leaf fragments collected from pioneer species in the diet in both habitat (86% in edge and 80.4% in interior). Edge colonies collected proportionally more fragments from pioneer species than colonies located in the forest interior. Our results are the first to demonstrate an edge-mediated relaxation of dietary restrictions in leaf-cutting ants. These findings render robust support to previous evidence indicating the reduction of bottom-up forces as a key factor explaining both edge-induced hyper-abundance and increased herbivory of leaf-cutting ants in human-modified Neotropical landscapes.

The orchid-bee fauna (Hymenoptera: Apidae) of a forest remnant in northeastern Brazil, with new geographic records and an identification key to the known species of the Atlantic Forest of northeastern Brazil

The orchid bee fauna of Estação Ecológica de Murici (ESEC Murici), in the state of Alagoas, one of the largest remnants of the Atlantic Rain Forest in northeastern Brazil, was surveyed for the first time. Seven hundred and twenty-one orchid-bee males belonging to 17 species were collected from the 3rd to the 10th of September, 2009. Besides the recently described Eulaema (Apeulaema) felipei Nemésio, 2010, three other species recorded at ESEC Murici deserve further attention: Euglossa amazonica Dressler, 1982b, recorded for the first time outside the Amazon Basin; Euglossa milenae Bembé, 2007 and Euglossa analis Westwood, 1840, both recorded for the first time in the Atlantic Forest of northeastern Brazil north to São Francisco river. These results together with previous samplings in the state of Alagoas reveal that at least 22 orchid-bee species are now known to occur there. Three other species not recorded for Alagoas yet are known from the neighbor states of Sergipe, Pernambuco, and Paraíba. An identification key to all 25 species of Euglossina known to occur in the states of Alagoas, Sergipe, Pernambuco, Paraíba, and Rio Grande do Norte is provided.

Ticks (Acari: Ixodidae) infesting wild birds in the Atlantic Forest in northeastern Brazil, with notes on rickettsial infection in ticks

A total of 232 individuals representing 46 species of birds were mist-netted and screened for ticks in a region of the Atlantic Forest, State of Bahia, Brazil. Thirty-eight (16.4%) of these birds representing 17 species were found infested by immature stages of Amblyomma ticks, namely, Amblyomma longirostre (Koch, 1844) (15 larvae and seven nymphs), Amblyomma nodosum (Neumann, 1899) (nine nymphs), Amblyomma calcaratum (Neumann, 1899) (five nymphs), Amblyomma cajennense (Fabricius, 1787) (seven larvae), and Amblyomma parkeri (Fonseca and Aragão, 1952) (four larvae). Overall, 21 larvae and five nymphs collected from birds could not be identified to species and were morphologically identified as Amblyomma spp. Among 13 A. longirostre larvae and two A. parkeri larvae, two individuals of A. longirostre (15.4%) were found infected by Rickettsia amblyommii. This study provides some bird species found infested by A. longirostre, A. parkeri, A. calcaratum, A. nodosum, or A. cajennense for the first time and expands the distribution of R. amblyommii-infected A. longirostre ticks.

Habitat fragmentation alters the structure of dung beetle communities in the Atlantic Forest

Habitat loss and fragmentation have turned into the most important threats to biodiversity and ecosystem function worldwide. Here we investigate the effects of habitat fragmentation and drastic changes in tree communities on dung beetle richness and community structure. This study was carried out in a severely fragmented 670-km 2 forest landscape of the Atlantic Forest of north-eastern Brazil. Sampling was carried out in 19 forest fragments between September 2007 and March 2008 with the use of pitfall traps and flight interception traps. A total of 5893 individuals and 30 species of dung beetle were collected. Fragment area and isolation were the most significant explanatory variables for predictable and conspicuous changes in dung beetle species richness. Smaller and isolated fragments presented lower number of species, but fragments with lower tree species richness and lower proportion of shade-tolerant species were also considerably impoverished in terms of dung beetle species richness. The body mass of dung beetles were explained by fragment area and the percentage of emergent trees with smaller and less stratified fragments being dominated by small-bodied dung beetles. An ordination analysis segregated dung beetle communities between small fragments (<100 ha) and the control area. Seventy-seven percent of the species were recorded in the control area and 22% of all species were unique to this habitat. Our findings indicate that large fragments in the Atlantic Forest appear to consist in a sort of irreplaceable habitats for particular groups of dung beetle species, as well as for the integrity of their communities.

Reptilia, Serpentes, Dipsadidae, Liophis taeniogaster Jan, 1863: distribution extension, new state record and geographic distribution map

The current work provides a new state record for the snake Liophis taeniogaster in Atlantic Forest of northeastern Brazil.

Pollination of Philodendron acutatum (Araceae) in the Atlantic Forest of Northeastern Brazil: A Single Scarab Beetle Species Guarantees High Fruit Set

Philodendron acutatum (Araceae) is a hemiepiphyte common to the Atlantic Forest of northeastern Brazil. In two localities, we studied the species’ breeding system and associations with flower‐visiting insects, along with an analysis of its floral scent composition. The fruit set of self‐incompatible P. acutatum was high, more than 90%, and inflorescences were exclusively pollinated by one species of scarab beetle, Cyclocephala celata (Scarabaeidae, Dynastinae). Pollinators are drawn toward the inflorescences at dusk by strong floral fragrances given off during the female phase of anthesis, along with endogenous heating of the spadix, whose temperatures were recorded at more than 11°C above ambient air. Two other species of flower‐visiting Cyclocephala were also consistently recovered in blacklight trappings during the flowering period of P. acutatum. The fact that only C. celata was found in association with P. acutatum suggests a local reproductive dependence of the plant to this scarab beetle species. D...

Biomass and abundance of termites in three remnant areas of Atlantic Forest in northeastern Brazil

Termite biomass and abundance were estimated in three remnant areas of Atlantic Forest in northeastern Brazil: Reserva Biológica de Pedra Talhada-RBPT (Alagoas State), Parque Estadual Dois Irmãos-PEDI (Pernambuco State), and Área de Proteção Ambiental Mata do Buraquinho-APMB (Paraíba State). A quantitative sampling of the termite assemblages present on trunks and leaf litter, in nests, and in the soil was undertaken during the months of June and July (rainy season) and November and December (dry season) of 2000. Thirty seven species of termites were encountered and quantified in the three remnant forest areas. The termite biomass varied from 10.09 to 11.30 g (fresh weight)/m² and abundance varied from 4911 to 5663 individuals/m². The subfamily Nasutitermitinae was dominant in terms of the number of species, biomass, and abundance. The soil-feeders were the most abundant at the three sites, while wood-feeders had the largest biomass at least at the PEDI and APMB sites. Among the microhabitats quantified, termites were most frequently encountered in the soil, being most heavily concentrated at depths of 0-20 cm. Two species stood out in terms of their biomass and abundance: Embiratermes parvirostris Constantino, on the soil, and Nasutitermes corniger (Motschulsky), on decomposing trunks and in nests. Estimates of biomass and abundance suggest that termites play an important role in the decomposition of the plant necromass in remnant forest areas of the Atlantic Forest in northeastern Brazil.

Nematode infection in the lizard Bogertia lutzae (Loveridge, 1941) from the Atlantic forest in north-eastern Brazil

Endoparasites associated with the small bromelicolous lizard Bogertia lutzae, a poorly studied phyllodactylid inhabitant of north-eastern Brazil, were studied. Fifty-seven specimens collected from the Atlantic Forest of Alagoas state were dissected. Only one species of parasite, the nematode Spauligodon oxkutzcabiensis, was found, with a prevalence of 22.8%. The intensity of infection was 2.62 +/- 1.19, and neither the prevalence nor mean intensity differed between the sexes. There was no correlation between lizard body size and intensity of infection. An aggregated pattern of distribution (D = 0.813) of S. oxkutzcabiensis was found in this lizard host population. Bogertia lutzae represents a new host recorded for S. oxkutzcabiensis, a parasite reported for the first time for Brazil.

Long-term erosion of tree reproductive trait diversity in edge-dominated Atlantic forest fragments

Habitat loss and fragmentation promote relatively predicable shifts in the functional signature of tropical forest tree assemblages, but the full extent of cascading effects to biodiversity persistence remains poorly understood. Here we test the hypotheses that habitat fragmentation (a) alters the relative contribution of tree species exhibiting different reproductive traits; (b) reduces the diversity of pollination systems; and (c) facilitates the functional convergence of reproductive traits between edge-affected and early-secondary forest habitats (5–32 years old). This study was carried out in a severely fragmented 670-km2 forest landscape of the Atlantic forest of northeastern Brazil. We assigned 35 categories of reproductive traits to 3552 trees (DBH⩾10cm) belonging to 179 species, which described their pollination system, floral biology, and sexual system. Trait abundance was calculated for 55 plots of 0.1ha across four habitats: forest edges, small forest fragments (3.4–83.6ha), second-growth patches, and core tracts of forest interior within the largest available primary forest fragment (3500ha) in the region. Edge-affected and secondary habitats showed a species-poor assemblage of trees exhibiting particular pollination systems, a reduced diversity of pollination systems, a higher abundance of reproductive traits associated with pollination by generalist diurnal vectors, and an elevated abundance of hermaphroditic trees. As expected, the reproductive signature of tree assemblages in forest edges and small fragments (edge-affected habitats), which was very similar to that of early second-growth patches, was greatly affected by both habitat type and plot distance to the nearest forest edge. In hyper-fragmented Atlantic forest landscapes, we predict that narrow forest corridors and small fragments will become increasingly dominated by edge-affected habitats that can no longer retain the full complement of tree life-history diversity and its attendant mutualists.

Edge‐mediated reduction of phorid parasitism on leaf‐cutting ants in a Brazilian Atlantic forest

AbstractPrevious studies have shown that leaf‐cutting ant populations benefit greatly from living in or near the edges of the Brazilian Atlantic forest. One of the mechanisms responsible for this rise in population density is an edge‐mediated increase of pioneer plants, resulting in increased food availability for the ants (i.e., less bottom‐up control). Here, we hypothesized that the release from natural enemies (i.e., less top‐down control) may also contribute to the phenomenon. We investigated whether parasitism of phorid flies on leaf‐cutting ants decreases in colonies located along the forest edge vs. the interior of a large tract of Atlantic forest in northeastern Brazil. For this, we assessed abundance and rates of oviposition attack by phorids in bimonthly intervals over a period of 1 year in 10 adult colonies of Atta cephalotes (L.) (Hymenoptera: Formicidae: Myrmicinae), five at the forest edge and five in the forest interior. The number of phorids attracted by ants at edge colonies was 40% lower than that at interior colonies. The temporal variation in phorid attraction was also significant, with approximately 35% fewer flies in the dry months as compared to the rainy months. As a result of lower phorid abundance, ant workers of edge colonies suffered three times fewer oviposition attacks than those of interior colonies. There was a tendency for fewer attacks during dry months, but the difference in the temporal variation was not significant. Our findings suggest that edge creation contributes to increased leaf‐cutting ant abundance, not only via the attenuation of bottom‐up forces, but also through an environmentally triggered depression of parasitoid abundance/efficiency, possibly because of adverse environmental conditions in edge habitats.

Fragmentation causes rarity in common marmosets in the Atlantic forest of northeastern Brazil

The purpose of this study was to investigate the population status of the common marmosets, Callithrix jacchus, in one of their main habitats, the northeastern Atlantic forest of Brazil, where only 2% of its original area remains as small and isolated forest fragments, to determine long-term viable populations. The study was carried out in 15 forest fragments, measuring from 3,478.3 ha (the largest) to 6 ha, which were invariably subjected to high human impact. Line transect surveys were carried out between January 2002 and December 2004, along transects measuring from 350 to 4,000 m, between 0500 h and 0900 h. Common marmosets were registered in 73% (n = 11) of the forest fragments, were not recorded in the largest one, the Coimbra Forest, and group sizes varied from 1 to 4 individuals. A negative significant relationship was detected between the size of the fragment and the number of sightings of common marmosets. It is shown that the number of groups of common marmosets dwelling in this highly impacted landscape is nowadays lower than necessary for long-term survival. Additionally, smaller fragments having more groups suggests that they live in total association with humans, which assure their subsistence through the supply of introduced and exotic foods.

Galhas entomógenas de Miconia prasina (Sw.) DC (Melastomataceae) em remanescentes de Floresta Atlântica Nordestina.

The objective of this work was to describe the morphology of the insect galls occurring in Miconia prasina (Melastomataceae) and their yearly frequencies in four remnants of Atlantic forest in northeastern Brazil. In each study area young individuals up to 2 m were marked and observed monthly for the number of galls. The leaf-galling insects induced elliptic, spherical and fusiform types in the leaf blade of M. prasina growing at four studied fragments; a cylindrical type in Refúgio Charles Darwin; and a piriform type in the axillary bud in the Cachoeira and Capoeirão fragments. In the selected individuals 1131 new galls were counted along a year. Of these, 548 were elliptic, 336 spherical, 125 fusiform, 81 cylindrical and 41 piriform. The gall inductors were generally registered in larger numbers in the most humid months. The results of this study contribute to increase the knowledge of Neotropical galls diversity.

Phylogenetic relationships of a new genus and species of microteiid lizard from the Atlantic forest of north-eastern Brazil (Squamata, Gymnophthalmidae)

A new genus and species of a short limbed and slightly elongate gymnophthalmid lizard is described from the Atlantic rain forests of north-eastern Brazil. The new genus is also characterized by short and stout pentadactyl limbs, presence of prefrontals, absence of frontoparietals, distinctive ear opening and eyelid, two pairs of genials, a distinct collar, smooth, quadrangular, dorsal scales, quadrangular ventrals, fused postfrontal and postorbital bones, and two pairs of sternal ribs. The geographical distribution of the new taxon extends from the state of Rio Grande do Norte to the northern bank of the Rio Sao Francisco in the state of Alagoas. All specimens were obtained in leaf litter, an observation which agrees with the fossorial habits suggested by the body shape and massive aspect of the head of this species. A phylogenetic analysis based on external morphology, osteology, and molecular data recovered the new lizard as the sister genus to Anotosaura, and Colobosauroides as the sister group to these two. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society, 2005, 144, 543−557.

Sleeping sites of common marmosets (Callithrix jacchus) in defaunated urban forest fragments: a strategy to maximize food intake

AbstractThe purpose of this study was to investigate if there was any species‐specific type and structure of sleeping sites of common marmosetsCallithrix jacchusand their key determinant. The study was conducted in an urban fragment of the Atlantic forest of north‐eastern Brazil, where a group of common marmosets was followed for 488 h. For this purpose we usedad libobservations, performed twice a week, when the animals were entering and leaving the sleeping sites, identified potential predators of the common marmosets through interviews with local people, and identified the trees that provided them with fruit and/or exudate during the study. Five sleeping sites were identified, all invariably in the border of the native forest and the orchard. No predators of common marmosets were seen by local people or recorded during this study, and the sleeping trees were located invariably in the place where there was the highest concentration of feeding trees, regardless of its structure. There was no species‐specific type and structure of sleeping places of common marmosets. The key variable defining the choice of a sleeping place was the availability and location of immediate sources of food.

Estudo das comunidades de aranhas (Araneae: Arachnida) em clareiras naturais e florestamadura de floresta atlântica - Parque Estadual de Dois Irmãos (Recife - Pernambuco - Brasil)

Disturbances are widely knowledge as an important factor in determining the structure of biological communities. In forest environments, the most common kind of disturbance is the formation of treefall gaps. The environment of treefall gaps differs in several ways from the one under mature forest, leading to differences in structure and composition of vegetation. Studies with plants and birds indicated that biological communities of treefall gaps and mature forests differ significantly. However, this pattern must be evaluated with other groups of organisms. This dissertation seeks to compare species richness, composition, guild distribution and seasonality of two groups of spiders (web-building spiders and e hunting spiders) found in treefall gaps and mature forests of a patch of Atlantic Forest in northeastern Brazil. This study was carried out at the Parque Estadual de Dois Irmaos (Recife, Pernambuco, Brazil), a remnant of Atlantic Forest that even though having only 387.4 ha, was ranked as of extreme biological importance. From June to November 2000, spider communities were sampled in 20 points (10 of treefall gaps and 10 of mature forest) by using two methods: pitfall traps and hand collecting. In addition, some environmental measurements were taken: temperature, litter structure and foliage density in different heights. Species richness was estimated by using the computer program EstimateS 5.0.1. The Jackknife 1 estimator was selected because its performance. A total of 3.926 spiders was collected, including 1.996 adults. A total of 970 adults was collected in treefall gaps, representing 112 species, distributed in 29 families. A total of 1026 individuals was collected in mature forest, representing 120 species distributed in 31 families. Mature forest and treefall gaps shared 79 species. Although treefall gaps and mature forests differ significantly in several environmental parameters, no significant difference was found between in composition, ..

Ecological relationships between feather mites (Acari) and wild birds of Emberizidae (Aves) in a fragment of Atlantic Forest in northeastern Brazil

The objective of this study was to investigate feather mites on birds of the Family Emberizidae, to collect data on the ecological ectoparasite-host relationship and infestation level. A sum of 94 birds of 9 species was captured at the Refugio Ecologico Charles Darwin, Igarassu, Pernambuco, Brazil, from August 1996 to July 1997. Five genera of mites from the superfamily Analgoidea were identified: Analges Nitzsch, 1818; Mesalgoides Gaud & Atyeo, 1967; Pterodectes Robin, 1877; Proctophyllodes Robin, 1877 and Trouessartia Canestrini, 1899. Among the 94 birds examined, 92 (97,87%) were infested. Regarding the prevalence, it was observed that the genera with higher percentage were, respectively, Pterodectes (88,04%), Proctophyllodes (56,52%) and Trouessartia (45,65%).

Brunettia bora, a New Species of Moth-fly (Diptera, Psychodidae) from Brazil

Brunettia bora spec. nov. is described from an area of Atlantic Forest in northeastern Brazil. It is the second species of Brunettia described from Brazil, although it is more similar to B. bistria Quate, 1996 from Costa Rica.

Seed dispersal, plant recruitment and spatial distribution of Martius (Arecaceae) in a remnant of Atlantic forest in northeast Brazil

Seed dispersal ecology of Bactris acanthocarpa Mart. (Arecaceae), an Atlantic forest understory palm, was investigated during two years as an attempt to test the following predictions: (i) seeds of Bactris are dispersed by mammals and large-gaped birds; (ii) Bactris benefits from seed dispersal in terms of seed predation avoidance, improvement of seed germination and seedling survival; and (iii) spatial distribution of adults is related to patterns of seed dispersal. The study was conducted at Dois Irmãos Reserve, a 387.4-ha reserve of Atlantic forest in northeastern Brazil (8º S–35º W). Black–rumped agoutis ( Dasyprocta prymnolopha ) and Guianan squirrels ( Sciurus aestuans ) were identified as the seed dispersers/predators, moving seeds short distances (< 4 m from parents) and at low rates (0.04-0.05 diaspore/palm/day). Pyrene burial prevented seed predation by vertebrates and reduced by half seed infestation by Scolytidae beetles. Only buried pyrenes germinated. Pyrene predation was not correlated with distance from conspecific adults. In contrast, early seedling mortality was higher near conspecific adults. Most adults (64%) had their nearest conspecific adult neighbour > 4 m away in contrast to 96% of seedlings that occurred concentrated within 4 m from adults (77% under the palm crowns). Here, we present evidence that spatial distribution of B. acanthocarpa is partly due to low rates of seed removal, short-distance seed dispersal by agoutis and squirrels, and early seedling mortality associated with presence of seedlings under palm crowns.