Deforestation in the Amazon Basin is still increasing, and the rehabilitation of these lands continues to be a challenge. Autoecological studies of most Amazonian species are rare, and efficient techniques for restoration of forested habitats have yet to be developed. The aim of this study was to test direct sowing as a rehabilitation technique for sites with different degrees of disturbance: bare soil, pasture, and secondary and mature forests in Central Amazonia, Brazil. At each site, we sowed seeds of 11 native tree species. Throughout the following year we evaluated germination and seedling survival. The germination differed according to the study site and species. Seedling survival in degraded sites was higher than in other areas. After 1 year in the bare soil site, 33% of the sown seeds of eight species developed seedlings; in the pasture the establishment was 23%, in secondary forest 15%, and in mature forest 12% of only four species. The only widespread survivor with more than 45% emergence in all perturbed sites was Caryocar villosum. No pioneer seedlings remained after 1 year. There was a positive correlation between seed size and survival. Large‐seeded non‐pioneer species seem to be more suitable for direct sowing than small‐seeded species. We recommend a combination of direct sowing and planting of seedlings as an appropriate means to accelerate the rehabilitation of degraded areas in Central Amazonia.

In the Central Amazon we investigated whether seedling performance (survival, and relative growth rates in height and leaf numbers) was affected by initial seedling size (height and leaf numbers) in habitats that varied in their degree of human disturbance: cattle pasture, young secondary forest, 1-ha forest fragment and old-growth forest. Additionally, effects of photosynthetically active radiation (PAR), litter standing crop (LSC) and insect herbivory were evaluated 12 mo after transplantation in seedlings from the native canopy trees Chrysophyllum pomiferum, Micropholis venulosa and Pouteria caimito. Seedling performance changed rank across the understorey environment depending on species. Seedlings of Chrysophyllum thrived in all conditions but under high PAR, Micropholis thrived only in intermediate light conditions, whereas Pouteria thrived under high PAR. Effects of initial seedling size, PAR and herbivory after 1 y were specific to species, whereas LSC had no effect on performance. Initially larger seedlings resulted in lower survival for Chrysophyllum and Pouteria. Herbivory affected seedling performance in all species. Negative effects of herbivory were intensified under low PAR. Overall, our results showed that, as seedlings, species of the same family and characteristic of old-growth forests respond differently to the environmental constraints present in contrasting human-disturbed conditions. Larger seedlings may not always present greater tolerance to physical and biotic mortality risks.

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RESUMOO processo tradicional de extração do óleo das sementes de andiroba foi levantado em três municípios (Anamã, Manacapuru e Silves) no Estado do Amazonas. Em 1992 e 2004, foi aplicado um questionário a 38 extratoras. Sementes das duas espécies de andiroba (Carapa procera D.C. e Carapa guianensis Aubl.) foram utilizadas como matéria prima. O processo tradicional é complexo, demora cerca de dois meses e pode ser dividido em três etapas: 1. A coleta, seleção de sementes boas e um primeiro armazenamento (3-15 dias). 2. O preparo da massa pelo cozimento das sementes em água (1-3 horas), um segundo período de armazenamento (até 20 dias) e finalizada pela retirada da casca e o amassamento das amêndoas. 3. A extração do óleo (até 30 dias), pelo gotejamento colocando a massa sobre uma superfície inclinada. Óleo extraído na sombra foi considerado de melhor qualidade do que no sol, porém o processo é mais demorado. Uma segunda extração com a prensa ("tipiti"), usada na fabricação de farinha, foi raramente empregada. Verificaram-se pequenas variações entre os procedimentos das extratoras, aparentemente com conseqüências na rentabilidade e na qualidade do óleo. Na primeira e segunda etapa da extração participaram membros da família e/ou vizinhos, ao contrário da etapa final, realizada por uma única mulher. Enquanto, transmissão do conhecimento tradicional, em geral, costuma passar de geração por geração pela oralidade e observação, este estudo revelou, que os jovens não participam mais da extração. Fato, que no futuro próximo, pode causar a perda de conhecimento em relação à extração do óleo de andiroba pelo método tradicional. PALAVRAS-CHAVESCarapa procera D.C., Carapa guianensis Aubl., Conhecimento popular, Semente oleaginosa, Rendimento. Crapwood oil: traditional extraction, use and social aspects in the state of Amazonas, Brasil ABSTRACTThe traditional method of oil extraction from crabwood seeds was observed in three municipalities (Anamã, Manacapuru e Silves) in the state of Amazonas. In 1992 and 2004 a total of 38 producers were interviewed. Seeds of two species (Carapa procera D.C. and Carapa guianensis Aubl.) were used for oil extraction. The complex process requires about two months and can be divided into three stages: 1. seed collection by gathering and storing good seed (3-5 days). 2. "seed cake" preparation by cooking the seeds in boiling water (1-3 hours), followed by a second storage period (up to 20 days), completed by removing the seed coat and kneading the seed mass; 3. Oil extraction (up to 30 days) by collecting the oil dripping from the "seed cake" placed on an inclined plate. Oil extracted in the shade was considered of better quality than in the sun, but the process needed more time. A second extraction with the press ("tipiti") used for manioc flour was rarely used. Comparing the methods of the producers, some minor variations were observed apparent consequences in yield as well as quality. The first and second stages of the process involved the collaboration of relatives and/or neighbors, wherea...

Forest edges bordering on pasture were created by cutting and burning the surrounding Amazonian lowland rain forest in the dry season (June) of 1990. Litterfall was measured for 3.5 y along transects 10, 50, 100 and 250-m into the forest from the forest edge. Litterfall along the 10-m transects increased by up to 2.5 times that on spatial controls (250-m transects) in the dry season in which the edge was created. In the second dry season after edge creation litterfall at 10-m was lower than on controls, after which it returned to control rates in the second wet season, 1.5 y after edge creation. Litterfall 50-m into the forest was less affected; there was a smaller rise in the dry season in which the edge was cut, and no significant effects after that. At 100-m there was no effect of edge creation on litterfall. Phosphorus concentrations in litterfall were elevated along 10-m transects, 10–12 wk after edge creation, possibly because of reduced retranslocation prior to abscission. The changes in litterfall described here are inextricably linked to the biomass collapse, which occurs near forest-fragment edges in the same area.

We assessed the effects of litter cover on herbivory and performance (annual survival and relative growth rate in height and leaf number) for established seedlings ( 2 9 cm tall, and 24 mo old), of four shade-tolerant, large-seeded, co-occurring Sapotaceae species. Seedlings were divided into three litter treatments: (1) litter addition, (2) control, and (3) continuous litter removal. The mean survival for all treatments in descending order were: Chrysophyllum pomiferum (89%), Pouteria peruviensis (84%), I? cuimito (75%), and Micropholis venulosa (40%). For all variables, species differed significantly within litter treatments. In M. venulosa, survival and relative growth rate in leaf number significantly decreased with the removal of litter, whereas herbivoiy increased. Relative growth rate in height of Z? peruviensis decreased significantly with litter removal, while the levels of herbivory were higher with the addition of litter. Conversely, litter quantity had no effect on the performance of C. pomiferum, but herbivory was lower in the removal treatment. Finally, in I? cuimito, litter treatment did not affect performance or herbivory. Results suggest that differences in litter quantity differentially affect tree species with similar biology (ie., large-seeds, shade tolerance) in life stages other than germination and early establishment. The variability in species' responses to litter might be an important factor in determining species richness, abundance, and distribution of tropical rain forest tree species at the seedling level. RESUMOEm Maiiaus, Brasil, foram medidas, durante um ano, as respostas de quatro espkcies de dossel em rela580 i diferenGas nas quantidades de massa de liteira fina, atravks dos parhetros sobreviv&ncia, taxa de crescimento relativo em altura e nlimero de folhas, e herbivoria. As plhtulas estabelecidas (altura 2 9 centlmetros, e idade 2 4 meses) foram plantadas em trCs tratamentos: (1) adiszo, (2), controle, e (3) remosiio continua da liteira. A porcentagem mkdia de sobrevivtncia de pldntulas em todos 0s tratamentos diminuiu de Chrysophyllum pom@rum (89%), para Pouteriaperuvimis (84%), para Pouteria caimito (750/0), e Micropholis venulosa (40%). Para todas as variAveis, as espkcies apresentaram diferenps significativas nos tratamentos de liteira. A sobreviv2ncia e crescimento em n6mero de folhas das pldntulas de M . venulosu diminuiu nas Areas nas quais a liteira foi removida, havendo aumento da herbivoria. 0 crescimento em altura das plhntulas de I?peruviemis diminuiu com a remos8o de liteira, havendo por outro lado, um maior nivel de herbivoria com a adis80 de liteira. Nas plhtulas de I? caimito e C pom@rum a quantidade de liteira n8o teve um efeito aparente no desempenho das pldntulas, mas 0s danos causados pela herbivoria em C: pom@rum foram menores no tratamento em que a liteira foi removida. 0 s resultados sugerem que a quantidade de liteira tem um efeito em outras etapas da vida das plantulas, fora da germinas80 e da fase itiicial de estabelecimento. A variayiio nas respostas ...

RESUMO -O araçá-boi (Eugenia stipitata ssp. sororia McVaugh -Myrtaceae) é uma espécie frutífera originária da Amazônia Ocidental que apresenta grande potencial para a indústria de sucos e sorvetes. A morfologia das sementes é complexa e sua fisiologia pouco compreendida. Sabe-se que elas são resistentes a injúrias mecânicas e sensíveis ao dessecamento. Objetivou-se caracterizar a morfologia das sementes através da biometria, determinar o grau de umidade das sementes e descrever os eventos do processo germinativo, visando dar subsídios para o manejo das sementes e a produção de mudas. As médias de comprimento, peso fresco e peso seco das sementes foram de 1,06 cm, 0,49 g c 0,17 g, respectivamente. O teor de água encontrado nas sementes foi de 62%. A germinação das sementes é hipógea c criptocotiledonar, mostrando-se lenta e desuniforme. A germinação iniciou-se por volta de 50 dias e estendeu-se até mais de 280 dias. A plântula, com 60 dias, apresentou altura média de 13 cm e 18 folhas. As sementes apresentam alto poder de regeneração pois, mesmo quando cortadas ao meio ou na zona meristemática, foram capazes de formar plântulas.Palavras chave: Eugenia Stipitata, Germinação de Sementes, Morfologia de Sementes, Sementes Recalcitrantes, Sementes Pseudomonocotiledonares, Frutífera da Amazônia. Morphology, Germination and Water Content of Seeds of Araçá-boi (Eugenia stipitata ssp. sororia)ABSTRACT -Araçá-boi (Eugenia stipitata ssp. sororia McVaugh -Myrtaceae) is a fruit tree native to western Amazonia. It has considerable potential in the juice and ice-cream industries. Seals of araça-boi have a complex morphology and their physiology is not well understood. They arc known to be resistent to mechanical injury and sensitive to drying. This study undertakes a biometric characterization of seed morphology, determines seed water content and describes the germination process, with a view to aiding seed handling and seedling production. Average seed length, fresh and dry weight were found to be 1.06 cm, 0.49 g and 0.17 g respectively. The water content was 62%. Germination, which is hypogcal and cryptocotyledonous, was observed to be slow and far from uniform; the first seeds germinated after about 50 days, while others took longer than 280 days. Sixty-day-old seedlings had an average height of 13 cm and had 18 leaves. Seeds showed a high capacity for regeneration; even when cut in the middle or in the meristematic zone, they still formed seedlings.