Size-related shifts in dietary composition of Centropomus parallelus (Perciformes: Centropomidae) in an estuarine ecosystem of the southeastern coast of Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ant communities (Hymenoptera: Formicidae) in an urban ecosystem near the Atlantic Rainforest

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Distribuição de macroalgas lóticas de uma bacia de drenagem no Parque Nacional da Serra da Canastra, Minas Gerais, Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bee communities (Hymenoptera: Anthophila) of the Cerrado ecosystem in São Paulo State, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Feeding behaviour and ecosystem role of the red mangrove crab Goniopsis cruentata (Latreille, 1803) (Decapoda, Grapsoidea) in a subtropical estuary on the brazilian coast

This study provides information concerning the feeding behaviour of Goniopsis cruentata (Latreille, 1803), through analysis of stomach contents according to demographic categories. Collections were carried out monthly from May 2005 through April 2006 in a subtropical estuary on the southeastern Brazilian coast (23 degrees 29'24 '' S 45 degrees 10'12 '' W). The crabs were collected by hand, with a 2-hour sampling effort by three people. In the laboratory, the crabs were sexed and measured for greatest carapace width, and grouped into demographic categories: adult males, juvenile males, adult females, juvenile females, and ovigerous females. For the fullness analysis, the stomachs were grouped into two categories: (1) E = Empty, with no food; and (2) F = Full, whether partially filled or totally. The frequency-of-occurrence method was used to characterize feeding behaviour, and the demographic categories recognired were compared. We obtained stomachs from 171 adult males, 69 juvenile males, 136 adult females, 72 juvenile females, and 41 ovigerous females, of which 85.6% were full. of the eight food items recorded, sediment was the most frequent, and unidentified material was the least. Goniopsis cruentata can be characterized as a generalist feeder, exploiting most of the food items available in the mangrove swamps. In spite of this generalist behaviour, the dominant presence of sediment suggests that G. cruentata is primarily a detritivore that exploits particulate organic matter from microbial biodegradation, one of the most important mangrove functions. The trophic role of this crab in the ecosystem showed no significant differences among the demographic categories, and seems to be wider than those observed for sesarmid and ocypodid mangrove crabs. These ecosystem engineers may occupy different positions in the trophic chains of estuarine environments.

Meiotic chromosomes and nucleolar behavior in testicular cells of the grassland spittlebugs Deois flavopicta, Mahanarva fimbriolata and Notozulia entreriana (Hemiptera, Auchenorrhyncha)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Distribuição ecológica de comunidades de macroalgas de ambientes lóticos do Parque Nacional de Itatiaia (RJ, MG), Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Crab spiders (Araneae: Thomisidae) in flowering plants in a Brazilian Cerrado ecosystem

Ainda que aranhas Thomisidae sejam comumente encontradas em flores, as associações desses aracnídeos a espécies de plantas e às suas características florais foram pouco registradas na região neotropical. Observações do hábito das plantas, visitantes florais, e também das características florais, tais como antese, odor, forma, cor e recursos da flor, foram assinaladas para espécies floridas de uma área de cerrado presentes em uma trilha de 2 km de extensão. Misumenops argenteus e Misumenops pallens representaram 62,86% das aranhas habitantes de 22 espécies de plantas floridas. As plantas Senna rugosa (Fabaceae), Styrax ferrugineus (Styracaceae) e Banisteriopsis campestris (Malpighiaceae) abrigaram, individualmente, cerca de 10 a 17% do total das aranhas e, nestas plantas, a antese diurna; flores de coloração atrativa a abelhas, como amarela (S. rugosa), branca (S. ferrugineus) e rosa (B. campestris) e as anteras poricidas, bem como a visita das flores por abelhas reforçou a evidência de síndrome de polinização para melitofilia. Este é o primeiro levantamento de espécies de aranhas Thomisidae associadas a plantas do cerrado brasileiro.

Quality of the forage apparently consumed by beef calves in natural grassland under fertilization and oversown with cool season forage species

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A novel technique to produce polygenic resistance to anthracnose in Stylosanthes capitata

An improved cultivar, based on 17 genotypes of S. capitata and six of S.macrocephala, was developed at the wEmbrapa Beef Cattle Research Center, Campo Grande, Brazil. The aim was to create durable, race non-specific resistance to anthracnose controlled by polygenic factors. A mass hybridisation technique was employed to produce a high degree of genetic diversity and sizeable quantities of seed of hybrid-derived progenies of Brazilian and Venezuelan genotypes of S. capitata. Outcrossing resulted in a significant improvement in the forage production of progeny of Venezuelan accessions. The multicross was evaluated in multilocational trials, each representing a large tract of country in the Cerrados ecosystem along a north-south transect from lat.6degrees S to 20degrees S. The genetic shift that occurred in S. capitata was a key element in the formation of the new cultivar. It is a complex mixture of two species, and a recombination of much desired forage traits of Brazilian x Venezuelan genotypes, high forage and seed yields coupled with anthracnose resistance. The new cultivar with its diverse genetic make-up has a wide application in the acid-soil savannas of tropical America. It was released by Embrapa for the Cerrados in 2000.

Food web structure in a tropical stream ecosystem

This study investigated the structure and properties of a tropical stream food web in a small spatial scale, characterizing its planktonic, epiphytic and benthic compartments. The study was carried out in the Potreirinho Creek, a second-order stream located in the south-east of Brazil. Some attributes of the three subwebs and of the conglomerate food web, composed by the trophic links of the three compartments plus the fish species, were determined. Among compartments, the food webs showed considerable variation in structure. The epiphytic food web was consistently more complex than the planktonic and benthic webs. The values of number of species, number of links and maximum food chain length were significantly higher in the epiphytic compartment than in the other two. Otherwise, the connectance was significantly lower in epiphyton. The significant differences of most food web parameters were determined by the increase in the number of trophic species, represented mainly by basal and intermediate species. High species richness, detritus-based system and high degree of omnivory characterized the stream food web studied. The aquatic macrophytes probably provide a substratum more stable and structurally complex than the sediment. We suggest that the greater species richness and trophic complexity in the epiphytic subweb might be due to the higher degree of habitat complexity supported by macrophyte substrate. Despite differences observed in the structure of the three subwebs, they are highly connected by trophic interactions, mainly by fishes. The high degree of fish omnivory associated with their movements at different spatial scales suggests that these animals have a significant role in the food web dynamic of Potreirinho Creek. This interface between macrophytes and the interconnections resultant from fish foraging, diluted the compartmentalization of the Potreirinho food web.

Coastal Marine Mapping as an Ecosystem Based Management - the case study of the Baixada Santista Region - São Paulo, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Food-web composition affects cross-ecosystem interactions and subsidies

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fish Migration, Dams, and Loss of Ecosystem Services in the Mekong Basin

The past decade has seen increased international recognition of the importance of the services provided by natural ecosystems. It is unclear however whether such international awareness will lead to improved environmental management in many regions. We explore this issue by examining the specific case of fish migration and dams on the Mekong river. We determine that dams on the Mekong mainstem and major tributaries will have a major impact on the basin's fisheries and the people who depend upon them for food and income. We find no evidence that current moves towards dam construction will stop, and consider two scenarios for the future of the fisheries and other ecosystems of the basin. We conclude that major investment is required in innovative technology to reduce the loss of ecosystem services, and alternative livelihood strategies to cope with the losses that do occur.

Mitigation of N2O emissions from grassland by nitrification inhibitor and actilith F2 applied with fertilizer and cattle slurry

Nitrous oxide (N2O) is involved in both ozone destruction and global warming. In agricultural soils it is produced by nitrification and denitrification mainly after fertilization. Nitrification inhibitors have been proposed as one of the management tools for the reduction of the potential hazards of fertilizer-derived N2O. Addition of nitrification inhibitors to fertilizers maintains soil N in ammonium form, thereby gaseous N losses by nitrification and denitrification are less likely to occur and there is increased N utilization by the sward. We present a study aimed to evaluate the effectiveness of the nitrification inhibitor dicyandiamide (DCD) and of the slurry additive Actilith F2 on N2O emissions following application of calcium ammonium nitrate or cattle slurry to a mixed clover/ryegrass sward in the Basque Country. The results indicate that large differences in N2O emission occur depending on fertilizer type and the presence or absence of a nitrification inhibitor. There is considerable scope for immediate reduction of emissions by applying DCD with calcium ammonium nitrate or cattle slurry. DCD, applied at 25 kg ha-1, reduced the amount of N lost as N2O by 60% and 42% when applied with cattle slurry and calcium ammonium nitrate, respectively. Actilith F2 did not reduce N2O emissions and it produced a long lasting mineralization of previously immobilized added N.