Summary 1We studied the dispersal system of the tree Clusia criuva (Clusiaceae) in a tropical rain forest in south-east Brazil. An observational/experimental approach was adopted to estimate the probability of transitions between consecutive stages in the recruitment process (i.e. fruit production and removal by birds, ant-seed interactions on the forest floor, seed germination, and establishment and early survival of seedlings). 2 Clusia trees produce hundreds of capsules with small lipid-rich arillate seeds. Crop size ranges from 393 to 3709 capsules per tree. Birds (14 species) eat 83% of the diaspores on the tree, while the remaining 17% fall to the ground and are removed by ants (16 species). 3 Ants remove 89% of the fallen diaspores and 98% of the seeds found in bird faeces. Ponerine ants ( Odontomachus , Pachycondyla ) carry the diaspores to their nests, while small myrmicines ( Pheidole , Crematogaster ) remove the aril where found. Aril removal by ants and removal of seeds from bird defecations increase germination success in C . criuva . 4 Seedlings are more frequent close to ponerine nests than in control areas without such nests. Early seedling survival (1 year) in nests of Pachycondyla striata is greater than in control areas. Soil samples from nests of P . striata also had higher concentrations of total nitrogen and phosphorus than random soil samples. 5 This is the first study to demonstrate the combined effects of ants on the distribution and survival of seedlings of a primarily vertebrate-dispersed plant in a tropical forest.

Fleshy diaspores (fruits, seeds) comprise a large portion of the litter on the floor of tropical forests, and interactions involving litter-foraging ants and diaspores are common in these areas. In this study, the interactions between ants and non-myrmecochorous diaspores (i.e. not adapted to dispersal by ants) were surveyed along a 1.4-km transect in a restinga forest (sandy soil) on the coast of south-eastern Brazil. During 2 y of monthly samplings, 562 interactions involving 48 ant species and 44 species of diaspore (0.02–11.10 g) were recorded. Ant–diaspore associations involved a considerable part of the ground-dwelling ant community. Large ponerine ants individually removed the diaspores up to 13 m, whereas small ants (myrmicines) normally recruited workers and consumed the diaspore on the spot. Ant-derived benefits to diaspores of non-myrmecochorous plants included secondary dispersal (small to medium-sized diaspores), and increased germination success after seed cleaning by ants. Large ponerine ants such as Odontomachus chelifer and Pachycondyla striata were the main seed vectors. Seedlings of three species were associated with nests of O. chelifer. The results indicate that ants play an important role in fruit/seed biology in the restinga forest.

This study examines the dispersal system of Guapira opposita in a tropical sandy rainforest in southeast Brazil. Guapira trees produce small fruits with a high protein content (28.4%) and low lipid content (0.3%), and the plant is primarily dispersed by birds. Mature fruits of G. opposita can fall spontaneously with the pulp intact, or be dropped by birds with bits of pulp attached. In either case, ground-dwelling ants rapidly remove the fruits to their nest (93% after 12 h). The ponerine ants Odontomachus chelifer and Pachycondyla striata are the main seed vectors among the ants, and together account for 56% (20 of 36) of the ant-fruit interactions recorded on the forest floor. Individual workers of O. chelifer and P. striata transport single fruits to their nests. Bits of pulp are fed to larvae and worker nestmates, and intact seeds are discarded outside the nest. Germination success in Guapira is higher for cleaned seeds (pulp removed) than for seeds coated by pulp. Guapira seedlings and juveniles are more frequent close to Odontomachus nests than at sites without such nests. Soil samples from Odontomachus nests had greater penetrability, and higher concentrations of P, K, and Ca than random soil samples. Field experiments suggest that the association between G. opposita seedlings and O. chelifer nests can potentially render the plant some protection against herbivores. Results indicate that fruit displacement by ponerine ants play an important role in the biology of G. opposita seeds and seedlings in the sandy forest, and illustrate the complex nature of the dispersal ecology of tropical tree species.

The reproductive biology of Manettia luteo-rubra was studied in the coastal montane Atlantic rain forest of southeastern Brazil. This Rubiaceae is a perennial vine that flowers all the year round, but has a flowering peak during the dry season. It presents reciprocal herkogamy, thus the plants are morphologically distylous. The morphs occur in a 1 : 1 ratio, and pollen diameter and corolla length vary between short and long-styled flowers. Manettia luteo-rubra displays typical heterostylous self-incompatibility and sets almost no fruits from self-or intramorph pollinations. The flowers are tubular, red with yellow lobes, and odourless. Anthesis is asynchronous, and the flowers last about four days. Concentration of sugars in nectar is similar in both morphs, ca. 24 YO, this concentration being typical for hummingbird flowers. Three species ofhummingbirds are the major pollinators of the flowers ofM. luteo-rubra at the study site: the hermits Phaethornis eurynome and P. squalidus, and the trochiline Thalurania glaucopis. Three species of Heliconius butterflies act as minor pollinators. Both morphs of M. luteo-rubra exhibit natural fruit-set of about 80 YO, this reproductive output being maintained throughout the year by the pollinators' constancy to the flowers. Kev wordsHeterostyly, breeding system, floral biology, hummingbird pollination, butterfly pollination.

This paper provides an overview of recent studies describing: (1) ant and plant species involved in the ant-diaspore interactions; (2) attributes of ants and diaspores that mediate the interaction; and (3) possible consequences of the interaction for plants. A study examined how these interactions vary spatially by comparing the patterns of selected ant-diaspore interactions occurring at two main study areas in the Brazilian Atlantic Forest (Sao Paulo): lowland forest and sandy plain forest (locally called 'restinga'). It is demonstrated that in the study area ground-dwelling ants interact frequently with fallen vertebrate-dispersed diaspores and that this may render recruitment benefits for some plant species. Possible causes underlying such patterns are examined and discussed, and avenues of future research are suggested.

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With the increasing use of recycled materials from civil construction, mainly as substitute for some aggregates in concrete mixtures, it is necessary to obtain technical information on the performance of these new mixtures. National and international research on the use of ceramic waste in concrete production highlight good results of this new material’s mechanical performance in environmental situations. However, little is known about its behavior at high temperatures. In this context, we sought to verify the performance of concrete mixtures produced with aggregates from ceramic block waste at high temperatures, with evaluation of their residual mechanical strength, axial compressive strength and elastic modulus, and also their tendency to spalling in fire situations. The RILEM-129 MHT method [1] was used for the assessment of residual mechanical strength, and the tendency to spalling was evaluated according to the procedure suggested by Souza and Moreno [2]. In both these evaluations, there is no national standard, and, in the case of spalling, not even an international standard. Three concrete mixtures were used, one prepared with natural coarse basalt aggregate (reference) and the other two by replacing part of this natural aggregate with aggregate from ceramic block waste (40% and 100% of substitution in volume). In the end, it is concluded that the substitution of natural coarse aggregate for lightweight aggregate from ceramic block waste can be an excellent alternative to increase the resistance of concrete to fire. Thus, the results of mechanical strength and spalling in a fire situation, unprecedented in our country, can greatly support the decision-making about the use of this alternative material in the national construction industry.

RESUMO O emprego de resíduo cerâmico na produção do concreto pode ser considerado uma ação viável em prol da sustentabilidade na indústria da construção civil. No entanto, faz-se necessário, o estudo das propriedades físicas e mecânicas do concreto produzido com este resíduo, garantindo segurança e necessária vida útil das edificações. Neste sentido, este trabalho avalia a durabilidade dos concretos produzidos com agregados provenientes de resíduos de cerâmica vermelha visando seu emprego na produção de elementos estruturais em concreto armado. Para tanto, foram produzidos traços com substituição do agregado graúdo natural pelo resíduo de cerâmica vermelha nos teores de 40 e 100% de substituição, em volume. Foram realizadas análises de carbonatação, absorção por permeabilidade capilar, permeabilidade ao ar e penetração por cloretos para verificação da durabilidade, bem como a verificação de suas propriedades mecânicas, em especial, resistência à compressão axial. Os resultados demonstraram menor permeabilidade para os concretos produzidos com resíduo cerâmico e, consequentemente, menor ataque por cloretos e carbonatação para misturas com até 40% de resíduo cerâmico, o que sugere, consequentemente, que elementos estruturais executados com estas misturas alternativas estariam menos propensos à corrosão das armaduras. A análise por microscopia eletrônica por varredura evidenciou uma redução no diâmetro dos poros capilares, resultado da melhor hidratação da fase cimentícia por meio do fenômeno conhecido por cura interna, proporcionado pelo emprego do agregado cerâmico reduzindo, também, a espessura da zona de transição interfacial entre o agregado e a matriz cimentícia.