Seed banks on Attalea phalerata (Arecaceae) stems in the Pantanal wetland, Brazil

Background and Aims

Seeds can accumulate in the soil or elsewhere, such as on the stems of palms when these are covered by persistent sheaths. These sheaths could act as a safe site for some species. Here, we studied whether persistent sheaths of the palm Attalea phalerata (Arecaceae) are available sites for seed accumulation in the Pantanal wetland of Brazil. We also investigated whether the composition, richness and diversity of species of seeds in the persistent sheaths are determined by habitat (riparian forest and forest patches) and/or season (wet and dry).

Methods

All accumulated material was collected from ten persistent sheaths along the stems of 64 A. phalerata individuals (16 per habitat and 16 per season). The material was then individually inspected under a stereomicroscope to record seed species and number.

Key Results

Of the 640 sheaths sampled, 65 % contained seeds (n = 3468). This seed bank included 75 species belonging to 12 families, and was primarily composed of small, endozoochoric seeds, with a few abundant species (Cecropia pachystachya and Ficus pertusa). Moraceae was the richest family (four species) and Urticaceae the most abundant (1594 seeds). Stems of A. phalerata in the riparian forest had 1·8 times more seeds and 1·3 times more species than those in forest patches. In the wet season we sampled 4·1 times more seeds and 2·2 more species on palm stems than in the dry season. Richness did not differ between habitats, but was higher in the wet season. Abundance was higher in forest patches and in the wet season.

Conclusions

Attalea phalerata stems contain a rich seed bank, comparable to soil seed banks of tropical forests. As most of these seeds are not adapted to grow in flooding conditions, palm stems might be regarded as safe sites for seeds (and seedlings) to escape from the seasonal flooding of the Pantanal.     

Two new species of <Emphasis Type="Italic">Erythroxylum</Emphasis> sect. <Emphasis Type="Italic">Rhabdophyllum</Emphasis> (<Emphasis Type="Italic">Erythroxylaceae</Emphasis>) from north-eastern Brazil

Summary   Erythroxylum longisetulosum I. Loiola & M. F. Sales and E. timothei I. Loiola & M. F. Sales (sect. Rhabdophyllum) from north-eastern Brazil are described and illustrated, and their taxonomic and ecological relationships are discussed.     

Geriatric dentistry: a new specialty in Brazil

Objective: To present the current status of geriatric dentistry in Brazil. Background: In 2001, the Brazilian Dental Council established a new specialty: geriatric dentistry. This decision was based on the increase in both the elderly population and the demand for dental treatment of this cohort. Materials and methods: Data were obtained through online searches of the Brazilian Dental Council and the Brazilian Institute of Geography and Statistics. Results: Brazil has 170 dental schools offering around 14 000 undergraduate vacancies every year. At the postgraduate level, there are 19 recognised dental specialties, one of which is geriatric dentistry, comprising 18 certificate programmes, with the potential to produce 216 new specialists every 18 months. The dentist/habitant ratio was 1:870, higher than that recommended by the Word Health Organization. The Brazilian population consists of around 14.5 million elderly people (8.6%). There were 124 specialists in geriatric dentistry distributed irregularly throughout the country. The specialist/elderly population rate was 1:117 249. At the undergraduate level, this new specialty is not included in the curricula of most dental schools in Brazil. Conclusions: Geriatric dentistry should be included in the undergraduate curricula of dental schools in Brazil. Postgraduate degree courses should be developed to produce more clinical academics and researchers in this field.     

我国东北土壤有机碳、无机碳含量与土壤理化性质的相关性

根据黑龙江、吉林、辽宁省和内蒙古地区相关历史资料数据,分析了我国东北表层土壤(0-50 cm)土壤相关理化性质与有机碳、无机碳的相关性,得到如下结论:土壤全氮、碱解氮、全磷、速效磷、速效钾、K⁺离子交换量、Fe₂O₃、P₂O₅、总孔隙度均与土壤有机碳含量呈显著正相关(R²=0.10-0.94, n=38-345, P<0.0001),但与土壤无机碳含量则大多呈显著负相关(R²=0.11-0.30, n=37-122, P<0.01);与此相反,土壤pH值、容重与土壤有机碳呈负相关(R²=0.36-0.42,n=41-304, P<0.0001),而与无机碳呈显著正相关(R²=0.29-0.31,n=39-125, P <0.01)。表层土壤有机碳、无机碳与土壤理化性质呈相反变化趋势的结果说明,由于土壤利用方式变化所导致的土壤理化性质改变对土壤无机碳和有机碳可能具有相反影响。在研究土壤碳平衡过程中,应该充分考虑这种关系所导致的相互补偿作用,即有机碳的增加,可能意味着无机碳的减少,或者反之。目前研究中普遍忽略无机碳的变化,可能导致生态系统碳收支计算显著偏差,所获得的经验拟合方程有利于对我国东北地区土壤碳平衡研究产生的这种偏差进行粗略估计。     

Joyeuses Tropiques: Five Encounters with Alterities in Brazil

The paper describes the predicament of Brazilian anthropology through a personal experience of teaching and living in Brasilia. Just like Brasilia, Brazil is many ways considered as “a work in progress” – and Brazilian anthropology as a lively and thriving area, although frequently overlooked by non-Brazilian scholars. The situation in which Brazilian anthropologists find themselves is put in the context of their own history, as well as the particular social conditions of the country – with special reference to Brazil as invention, taking as an example celebration of “500 years of Brazil.”     

Foraminiferal ecological zonation along a Brazilian mangrove transect: Diversity, morphotypes and the influence of subaerial exposure time

Two foraminiferal associations comprising only arenaceous species define two distinct environments in a 340 m-long mangrove transect at Cardoso Island, Trapandé Bay (Cananéia-Iguape estuarine system, SP, Brazil). The “lower muddy flat” (LMF), from the outer mangrove fringe inwards towards land (100 m), is positioned in the lower plain between 0.04 and 0.23 m above the mean sea level (msl), and remains subaerially exposed between 48.5 and 65.6% of the time. This environment is characterized by higher foraminiferal diversity and evenness (McIntosh's D = 0.54 ± 0.21 and Pielou's E = 0.68 ± 0.25, respectively) and is dominated by Arenoparrella mexicana and Trochammina inflata, and to a lesser extent by Ammotium directum and Textularia earlandi. The mangrove plant of this segment is a Rhizophoretum with average height of 8.4 ± 1.2 m. The sediment is characterized by higher concentration of organic matter (93.5 ± 32.3 g dm⁻³) and metals (e.g. V = 53.4 ± 21.8 ppm and Zn = 46.4 ± 21.3 ppm). The “upper sandy flat” (USF), 240 m wide along the transect, is positioned in the upper plain between 0.28 and 0.89 m above the msl, and remains subaerially exposed between 69.7 and 98.5% of the time. This environment is characterized by a lower diversity and evenness (D = 0.33 ± 0.17 and E = 0.49 ± 0.20, respectively). The association is dominated by species T. inflata and Miliammina fusca. The Rhizophoretum exhibits a lower average height of 3.6 ± 0.6 m. The sediment is poorer in organic matter (39.3 ± 15.0 g dm⁻³) and metals (e.g. V = 13.0 ± 6.8 ppm and Zn = 6.9 ± 3.7 ppm). Whereas “elongate” tests (uniserial, biserial and planospiral followed by a uniserial portion) are restricted to the LMF, “spiraled” species dominate the USF. Subaerial exposure time seems to exert a primary influence on species distribution, in addition to salinity and sediment type. Species may be adapted to different exposure times, a factor dependent on their position on the intertidal zone and the tidal regime, which should be taken into account in relative sea level reconstructions based on intertidal foraminifera. These patterns have important implications for studies investigating the ecology and paleoecology of foraminifera and subtle fluctuations in relative sea level during the Quaternary.     

Relationship between oocyte morphology and reproductive strategy in loricariid catfishes of the Paraná River, Brazil

Relationships between ovarian structure, oocyte structure/development, and parental care/life history strategies of six loricariid catfishes common in the upper Paraná River, Brazil were examined with analysis of catch data, relative gonad weight, histology, and microscopy. Three life history strategies were observed. Loricariichthys platymetopon , Loricariichthys sp. And Loricaria sp. produce several small clutches of large eggs over a protracted spawning period. Males of these species guard their eggs and larvae, which are transported as a mass on the ventral surface of the male's body. Hypostomus ternetzi and Megalancistrus aculeatus produce the largest mature eggs and the smallest clutches relative to adult mass. The spawning periods of these species are short, and males guard their broods in excavations. Rhinelepis aspera has high fecundity, high relative mass of mature gonads (both sexes), small mature eggs, and broadcast spawning with no parental care. This species migrates to spawn over firm substrates in channel areas during a contracted period. Mature oocytes of external bearers had the thickest zona radiata, followed by the egg scatterer, and cavity nesters. The thickness of the zona radiata probably is an adaptation to protect the developing egg from injury from abrasion. The zona granulosa appeared to be associated with production of secretions responsible for egg adhesion, and this layer was thickest in mature oocytes of the cavity nesting species, followed by the external bearers. All six species have wide distributions in the Paraná River, tributaries, floodplain lagoons, and the Itaipu Reservoir, but brood guarders tended to be most common in lentic habitats.     

Exploitation of Fallen Diaspores by Ants: Are there Ant–Plant Partner Choices?

Ants frequently interact with fleshy fallen diaspores (fruits or seeds) not adapted for ant‐dispersal. Such interactions are usually considered as opportunistic, but recent evidence has indicated that these ants may differ in their effects on diaspore survival and plant recruitment. We investigated if partner choices are recognizable among genera of ants and plants, and if ant and plant traits may influence such preferences in cerrado (savanna‐like vegetation) from southeast Brazil. During a 2‐yr period, 521 ant–diaspore interactions were recorded through various methods, yielding 71 ant species and 38 plant species. Exploitation of fallen diaspores was common among several ant genera, and included carnivorous, omnivorous, and fungivorous ants. Contrary to others areas around the world, where true myrmecochory (seed dispersal by ants) is common among shrubs, ants also exploited diaspores from several cerrado trees. Plant life form, diaspore size, and ant body size did not seem to explain the pattern of interactions observed. Two subsets of preferential interactions, however, segregated fungivorous ants from another group composed of carnivorous and omnivorous ants, probably influenced by the chemical composition of the plant diaspores. Omnivorous ants usually remove the fleshy portion of diaspores on spot and probably provide limited benefits to plants. Carnivorous and fungivorous ants usually remove the whole diaspore to the nest. As each of these ant groups may influence the fitness of diaspores in different ways, there are possible subtle pathways for the evolution of partner choices between ants and these non‐myrmecochorous diaspores.     

Evaluation of the WHO classification of dengue disease severity during an epidemic in 2011 in the state of Ceará, Brazil

In 2009, the World Health Organization (WHO) issued a new guideline that stratifies dengue-affected patients into severe (SD) and non-severe dengue (NSD) (with or without warning signs). To evaluate the new recommendations, we completed a retrospective cross-sectional study of the dengue haemorrhagic fever (DHF) cases reported during an outbreak in 2011 in northeastern Brazil. We investigated 84 suspected DHF patients, including 45 (53.6%) males and 39 (46.4%) females. The ages of the patients ranged from five-83 years and the median age was 29. According to the DHF/dengue shock syndrome classification, 53 (63.1%) patients were classified as having dengue fever and 31 (36.9%) as having DHF. According to the 2009 WHO classification, 32 (38.1%) patients were grouped as having NSD [4 (4.8%) without warning signs and 28 (33.3%) with warning signs] and 52 (61.9%) as having SD. A better performance of the revised classification in the detection of severe clinical manifestations allows for an improved detection of patients with SD and may reduce deaths. The revised classification will not only facilitate effective screening and patient management, but will also enable the collection of standardised surveillance data for future epidemiological and clinical studies.