Forest In Northeast Brazil Research Articles

Distribution of poroid fungi (Basidiomycota) in the Atlantic Rain Forest in Northeast Brazil: implications for conservation

The poroid fungi are macroscopic fungi whose fertile surface is usually poroid. Most of them are saprobes on dead wood and play fundamental role in nutrient cycling, mostly releasing carbon removed from the atmosphere by autotrophic organisms. Despite their importance, little is known about factors affecting polypore occurrence in the Neotropics. In this study, it was tested what abiotic and/or biotic conditions shapes distinct polypore communities in the Atlantic Rain Forest in Northeast Brazil by comparing (1) the composition of the species between coastal and montane forest and between dry and rainy season; (2) the similarities among areas against distance, and (3) the abundance of the species on logs of different sizes and decay stages. One hundred and ten transects (sampling units) were visited from 2008 to 2014, resulting in 138 species of poroid fungi, 80 % of them of infrequent occurrence. According to the Analysis of Similarity and PERMANOVA, the fungal communities did not form distinct groups in relation to the forest type or season, but the areas were different from each other and the variation can be partially explained by the distance among them when using linear regression. The poroid fungi were more frequently recorded in logs of decay stage 1 and 2 and their size had little, if none, effect on polypore occurrence. Thus, we suggest the protection of every fragment of any type of Atlantic Rain Forest and that dead wood should be not removed from a forest in order to protect polypore diversity.

Spatially Heterogeneous Nest-Clearing Behavior Coincides with Rain Event in the Leaf-Cutting Ant Atta cephalotes (L.) (Hymenoptera: Formicidae).

Leaf-cutting ants of the genus Atta construct the probably largest nests among ants and are ecosystem engineers because they alter light and nutrient availability at nest sites. Besides creating canopy gaps in the forest, workers remove all vegetation from atop their nest mounds. Here, we examined the extent and spatial distribution of this nest-clearing behavior by transplanting Licania tomentosa seedlings on Atta cephalotes (Linnaeus) nest mounds in the Atlantic forest in northeast Brazil and documented defoliation patterns by the workers. Within 9 days, workers removed around 53% of the total leaf area planted per colony. All colonies showed a synchronized start of defoliation after a rain event in the fifth night after the seedlings had been transplanted. Defoliation increased with time elapsed since transplanting and with the number of entrances surrounding each seedling. In addition, workers started defoliation on the top of the mound. In contrast, the distance to the next entrance and the size of the seedling did not affect the defoliation pattern. Defoliation was not part of the colony foraging activities but was identified as an element of nest maintenance. Possible cues triggering nest-clearing behavior and the potential link between nest-clearing activities and the control of microclimate of ant nests are discussed.

<I>Geastrum</I> from the Atlantic Forest in northeast Brazil — new records for Brazil

<I>Geastrum</I> from the Atlantic Forest in northeast Brazil — new records for Brazil

Can green iguanas compensate for vanishing seed dispersers in the A tlantic forest fragments of north‐east B razil?

The Atlantic forest of Brazil is a biodiversity hot spot, but is extremely fragmented. Local extinction of important seed dispersers, such as primates, threatens the maintenance of these fragments. It is important to evaluate the capacity of fragment-tolerant species to disperse seeds and help maintain plant communities within fragments. Green iguanas Iguana iguana are large, fragment-tolerant, canopy-dwelling lizards and have been noted to disperse seeds. We described the seed dispersal patterns produced by green iguanas in six urban forest fragments (1.2–8 ha in size) in the Atlantic forest of north-east Brazil, over 20 months. A total of 294 seeds were counted in 321 scats, and 12 plant species were dispersed. The largest seeds dispersed were 14.9 mm long and up to 9.2 mm wide. Iguanas deposited 86.9% of scats within latrines, which were used over a mean of at least 9 months. We show that iguanas can be effective seed dispersers and might partially replicate deposition patterns produced by howler monkeys in other studies. It is critical that we improve our understanding on the functional roles played by these cryptic, yet common, iguanas in order to determine whether they could buffer the negative effects caused by the local extinction of primates from forest fragments.

(2260) Proposal to conserve the name Piresia against Reitzia (Poaceae, Bambusoideae)

Piresia Swallen and Reitzia Swallen are two genera of Neotropical herbaceous bamboos that belong to the grass tribe Olyreae and include, respectively, five (Carvalho & al. in Syst. Bot. 37: 134–138. 2012) and only one described species (Judziewicz & al. in Amer. Bamboos: 314–316. 1999). Piresia presents a wide distribution in South America, occurring as a clear disjunction between the Amazon basin and the Atlantic forest in northeast Brazil, from the state of Pernambuco to Bahia (Judziewicz & al., l.c.; Carvalho & al., l.c.). On the other hand, Reitzia ranges in a smaller area, covered exclusively by Atlantic forest, and it was originally considered by Swallen (l.c. 1956) as endemic to the state of Santa Catarina, in south Brazil, being afterwards cited for Sao Paulo (Clark in Wanderley & al., Fl. Sao Paulo 1: 49. 2001) and Rio de Janeiro, both in southern Brazil (Oliveira & al. in Almeida & Teixeira, Anais I Semin. Nac. Bambu, ed. 2: 62–68. 2011). In the original publication of Piresia (Swallen, l.c. 1964), it was considered closely related to Reitzia, based on glumes of fertile spikelet 3-nerved, and differing from it by glume nerves prominent, fruit pubescent and culms biform (vs. glume nerves faint, fruit glabrous and culms all alike in Reitzia). Piresia has raceme-like inflorescences in culms of two types: aerial ones, bearing broad and flat leaf blades at the top; and fertile ones, often decumbent, shorter, bladeless or with very much reduced leaf blades, usually hidden among leaf litter or even burrowing through it (Soderstrom in Brittonia 34: 199–209. 1982; Soderstrom & Calderon in Biotropica 6: 141–153. 1974), while Reitzia also includes raceme-like inflorescences, but only at the apex of aerial culms, partially covered by the leaf blades (Judziewicz & al., l.c). There are other characters described in Clayton & al. (Grass Base; http://www.kew.org/data/grasses-db/www/imp08878.htm, accessed 23 Jun 2013) that are quite similar between Piresia and Reitzia, such as the number of culms, shape and distribution of the leaves in the culms, the number and position of male and female spikelets in the inflorescences (the female being terminal, with two male adjacent), the absence of glumes in male spikelet, as well as three lodicules and three stamens. Beside this, Reitzia shares with some members of Piresia bisexual and not typically dimorphic spikelets, being unusual among genera of herbaceous bamboos, which display predominantly unisexual and dimorphic spikelets (Soderstrom & Calderon, l.c.). This little differentiation between male and female spikelets of Reitzia occurs especially in species of Piresia from the Atlantic forest (Carvalho & al., l.c.), as well as in Diandrolyra Stapf, another herbaceous bamboo genus endemic to the same Brazilian biome (Oliveira & Clark in Novon 19: 209–215. 2009). Based especially on the type and position of the inflorescence, Clayton & Renvoize (Genera Graminum: 64–65. 1986) considered Piresia to be close to Diandrolyra, while Reitzia was treated together with Maclurolyra Calderon & Soderstr. and Rehia Fijten. However, recent phylogenetic studies in Olyreae did not indicate a relationship between Piresia and Diandrolyra (Oliveira & al., subm.). Ongoing studies on the systematics and evolution of Piresia based on multiple approaches (Carvalho, Estud. Biossistematicos Piresia [thesis, UEFS, Bahia]: 232. 2013) have shown that the diversity of this genus is high, as early suggested by Clayton & Renvoize (l.c.), including at least nine undescribed species. Using five regions of plastid and nuclear DNA, Carvalho (l.c.) identified Reitzia as nested in a clade together with the species of Piresia, but without clear resolution of their relationships. In order to resolve the status of the group as monophyletic, Piresia and Reitzia will likely be considered a single genus, and there are many more species that resemble the morphology of Piresia than

Fragment size and local flower density influence seed set of the understorey tree Paypayrola blanchetiana (Violaceae) in Brazilian Atlantic rain forest

Abstract:Reproductive success of many plant species declines in fragmented habitat, but this effect is little studied in trees of tropical rain forest understorey. Paypayrola blanchetiana (Violaceae) is a continuous-flowering treelet endemic to the Atlantic rain forest of north-east Brazil. Plants are distributed in localized patches. Flower, fruit and seed production of a total of 86 trees was quantified in six forest fragments, each belonging to one of two categories of size (> 300 ha vs. < 50 ha) and fragmentation history (isolated for c. 25–30 y vs. at least c. 50 y). Relative fruit set (fruits/flower) and seed set (seeds/ovule) were calculated for a spatial (total fruit set of tree individuals) and a temporal analysis (combined month-by-month fruit set in patches in response to different flowering intensities). Fruit set (1%) and seed set (0.6%) were very low, but variable among trees. Plants in large fragments had significantly higher fruit set and seed set than plants in small fragments. Trees in older fragments, however, displayed similar fruit and seed set to those in recently created ones. We found no interaction effect on seed set of fragment size and isolation time. Seed set was a negative function of patch flower density. Possible drivers of the observed patterns are discussed.

Resposta da comunidade de formigas aos atributos dos fragmentos e da vegetação em uma paisagem da Floresta Atlântica nordestina

The objective of this study was to determine the effects of forest fragmentation on ant richness in a landscape of Atlantic Forest in Northeast Brazil. More specifically, the ant richness was related to the attributes of fragments (area and distance from the fragment central point to the edge), landscape (forest cover surrounding the fragments), and tree community (plant density, richness, and percentage of shade tolerant species). The surveys were carried out in 19 fragments located in Alagoas State from October 2007 to March 2008. Samples were collected through a 300 m transect established in the center of each fragment, where 30 1-m² leaf litter samples were collected at 10 m intervals. A total of 146 ant species was collected, which belonged to 42 genera, 24 tribes and nine subfamilies. The attributes of fragments and landscape did not influence ant richness. On the other hand, tree density explained ca. 23% of ant richness. In relation to functional groups, both density and richness of trees explained the richness of general myrmicines (the whole model explained ca. 42% of the variation in this group) and percentage of shade tolerant trees explained the richness of specialist predator ants (30% for the whole model). These results indicate that ant fauna is more influenced by vegetation integrity than by fragment size, distance to edge or forest cover surrounding fragments.

Abundance and stratification of soil macroarthropods in a Caatinga Forest in Northeast Brazil

In arid and semiarid environments, seasonality usually exerts a strong influence on the composition and dynamics of the soil community. The soil macroarthropods were studied in a Caatinga forest located in the Reserva Particular do Patrimônio Natural (RPPN) Fazenda Almas, São José dos Cordeiros, Paraíba, Brazil. Samples were collected during the dry and rainy seasons following the method proposed by the Tropical Soil Biology and Fertility Program (TSBF), with minor modifications. At each station, 15 soil blocks (20 × 20 × 30 cm: 12 L) were extracted and divided into three layers: A (0-10 cm), B (10-20 cm), and C (20-30 cm). In the rainy and dry seasons 1,306 ± 543(se) and 458 ± 212 ind.m-2 macroarthropods were found, respectively, with 35 and 18 respective taxa recorded. The abundance of individuals and taxa were significantly higher in the rainy season. Isoptera (57.8%) was the most abundant taxon, followed by Hymenoptera: Formicidae (17.2%), Coleoptera larvae (7.3%), and Araneae (3.5%). In the rainy season, abundance in layer A (576 ± 138 ind.m-2) was significantly higher than that of layer C (117 ± 64 ind.m-2), but was not different from layer B (613 ± 480 ind.m-2). There was also no difference between the layer B and C abundances. In the dry season, abundance in layer B (232 ± 120 ind.m-2) was not significantly different compared to layer A (182 ± 129 ind.m-2), but was significantly higher than abundance in layer C (44 ± 35 ind.m-2). During the rainy season, layer A (34 taxa) was significantly richer in taxa than layers B (19 taxa) and C (11 taxa). On the other hand, during the dry season the richness of layers A (12 taxa) and B (12 taxa) was equal, but significantly higher than that of layer C (6 taxa). Richness of taxa and abundance were positively correlated with soil organic matter and negatively correlated with soil temperature. The community of soil macroarthropods in the area of Caatinga studied has taxonomic and functional structures that are relatively complex and is therefore likely to exert an influence on ecosystem productivity due to its physical effects on soil profile and necromass fragmentation, as occurs in other arid and semiarid ecosystems throughout the world.

Staphylococcus aureus Mastitis in a White-Eared Opossum (Didelphis albiventris) in the Atlantic Forest of Northeast Brazil

This is the first brief communication of clinical mastitis caused by Staphylococcus aureus occurring in a white-eared opossum (Didelphis albiventris) captured in a remnant of the Atlantic Forest in northeast Brazil. The bacterium was cultured from a milk sample by using sheep blood and Levine agars. Phenotyping of S aureus was performed with coagulase biochemical tests, DNase agar, mannitol agar, and anaerobic glucose and mannitol fermentation.

Cutting More from Cut Forests: Edge Effects on Foraging and Herbivory of Leaf‐Cutting Ants in Brazil

ABSTRACTEdge‐mediated changes in species composition are known to result in modified species interactions. Because of the crucial trophic position of herbivores and their far‐reaching impact on plant communities, it is important to understand how edge influences herbivory. In the present paper, we investigated whether and how leaf‐cutting ant foraging is altered in the forest edge, as this habitat is characterized by an increased proportion of pioneer species. We assessed basic foraging data as well as the herbivory rate (i.e., the proportion of the leaf material harvested by a colony in relation to the available leaf area in the foraging area) of Atta cephalotes colonies at the edge versus interior sites of a large remnant of the Atlantic forest in Northeast Brazil. Our results indicated clear edge effects on leaf‐cutting ants: equally sized A. cephalotes colonies located at the forest edge removed about twice as much leaf area from their foraging grounds than interior colonies (14.3 vs. 7.8%/col/yr). This greater colony‐level impact within the forest edge zone was a consequence of markedly reduced foraging areas (0.9 vs. 2.3 ha/col/yr) and moderately lower leaf area index in this habitat, whereas harvest rates were the same. Our results suggest that forest edges induce increased leaf‐cutting ant herbivory, probably via the release of resource limitation. Together with the increase of leaf‐cutting ant populations along forest edges, this may amplify environmental changes induced by habitat fragmentation.

Seed shadow, seedling recruitment, and spatial distribution of Buchenavia capitata (Combretaceae) in a fragment of the Brazilian Atlantic Forest

Here we describe the seed shadow, seedling recruitment, ontogenetic structure and spatial distribution of Buchenavia capitata (an emergent canopy tree) in a 380-ha fragment of the Atlantic forest in northeast Brazil. In particular, we examine seed distribution around 10 parental trees and both seedling recruitment and mortality, during an 18 month period beneath and around parental trees. Moreover, we describe: (1) B. capitata occurrence within treefall gaps; (2) population structure in terms of ontogenetic stages for the whole site; and (3) spatial distribution of adults within an area of 51 hectares. 99% of seeds were found beneath parent crowns (n = 4,236) and seed density reached 14.6 +/- 29.9 seeds/m2 (0-140 seeds/m2). 49% of all seeds germinated but seedling mortality reached 100% after an 18 month period. In addition, saplings of B. capitata were not found in forest understory and within 30 treefall gaps (94-2,350 m2). The adults showed an average DBH of 69.3 +/- 22.1 cm, were 19.2 +/- 2.9 m tall and presented a clumped spatial distribution. B. capitata matched some of the features presented by shade intolerant trees or large-gap specialists, and we hypothesize that low rates or even lack of long distance seed dispersal events may be reducing the probability of B. capitata seeds reaching suitable habitats for successful seedling recruitment and growth. Because of that (1) seedlings face high levels of early mortality; (2) there is no sapling recruitment at the study site; and (3) local population faces senility and it is threatened by local extinction.

New records of Aphyllophorales (Basidiomycota) in the Atlantic Rain Forest in Northeast Brazil

Non-poroid Aphyllophorales (Basidiomycota) in areas of the Atlantic Rain Forest in Northeast Brazil are reported. Auriscalpium villipes (Lloyd) Snell & E.A. Dick, Climacodon pulcherrimus (Berk. & M.A. Curtis) Nikol., Gloeodontia discolor (Berk. & M.A. Curtis) Boidin, Irpex lacteus (Fr.: Fr.) Fr. and Scytinostroma duriusculum (Berk. & Broome) Donk are new records to Northeast Brazil.

Nest spacing and architecture, and swarming of males of Dinoponera quadriceps (Hymenoptera, Formicidae) in a remnant of the Atlantic forest in Northeast Brazil.

Dinoponera quadriceps is a queenless neotropical ponerinae ant. Nest spacing and abundance were investigated in a remnant of the Atlantic forest in Northeast Brazil. Males were captured with a light trap between August 1994 and July 1996. Nest density varied from 15 to 40 ha(-1). An overdispersion of nests suggests that the intraspecific competition may be an important factor regulating their spatial arrangement. Territory size was correlated with worker population size of the colonies. The nests had up to 16 chambers, with variations in their architecture closely related to habitat diversification. Populations varied from 12 to 97 adult workers per nest, with a mean density of 1,618 workers ha(-1) and a live biomass of 461 g ha(-1) (n = 13 nests). Males swarm continually throughout almost all months of the year, suggesting that production and swarming are more influenced by mechanisms that regulate the sexual activity of workers than by climatic factors.

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.