While the potential of agroforestry products to contribute to rural livelihoods is well-recognized, the quantification of their yields, incomes, and value for domestic consumption (VDC) and knowledge about their relationships with biodiversity are still scarce. This information is crucial for choosing the best strategy for growing cocoa in tropical landscapes while conserving biodiversity and enhancing ecosystem services. We analyzed the contribution of cocoa agroforestry farming to the incomes and domestic consumption of small farmers¿ families in 179 cocoa agroforestry systems (CAFS) (254 ha) in five Central American countries. The two hypotheses were: (1) agroforestry products are as important as cocoa in contributing to livelihoods, (2) the typology of CAFS determines the relationships between socioeconomic indicators and yield, biodiversity, and structure of the shade canopy, as well as the relationships between plant species richness and cocoa yield. We quantified the yields of agroforestry products and their contribution to net income, cash flow, and family benefits and developed a typology of CAFS production to evaluate relationships for each CAFS cluster. The main agroforestry products other than cocoa were bananas, oranges, peach palm, other fruits, and timber, which generated modest cash incomes but high VDC at low cash costs, thus contributing to family savings and food security. Timber volumes and harvest rates were low but significant increase was deemed feasible. The contribution of the set of agroforestry products to family benefits was similar or higher than cocoa, depending on the typology of the CAFS. Intensified highly diverse-dense CAFS demonstrated remarkably higher yields, net income, cash flow, and family benefits, and had more synergetic relationships than extensive CAFS and traditional highly diverse-dense CAFS, which showed more trade-offs. Our findings point to intensified highly diverse-dense CAFS as feasible for farming within a land-sparing strategy. Further research is needed to better understand the mechanisms that could regulate synergies or trade-offs to improve this type of intensification. (Résumé d'auteur

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The fishways built in Latin America were mainly based on those used in the northern hemisphere for passing salmonids upstream. However, the swimming capacity in terms of speed and endurance is a major factor concerning the design of a fishway, and this information is not available for migratory neotropical fish species. Therefore, studies on swimming performance of neotropical species is fundamental. The aim of this study was to estimate the critical, sustained and prolonged speeds for the piau-três-pintas Leporinus reinhardti, and to evaluate the influence of water temperature on the swimming performance of the species. Variable (increasing) and fixed velocity tests were performed in a respirometer. When compared to other species whose critical speed data are available, the piau showed higher speeds, for a given total length. Fatigue times per prolonged speed class were estimated as well as prolonged speed per fatigue time class. The changing point from sustained to prolonged swimming was estimated to occur approximately at a speed of seven body-lengths per second (1.12 m/s for an individual with 16 cm total length: the first maturation length). In spite of the great swimming performance of piau, the adoption of efficient directives in fishway projects to allow the passage of neotropical ichthyofauna, will depend on a more detailed analysis of the swimming capacity of different species.As passagens para peixes construídas na América Latina são principalmente baseadas nos dispositivos existentes no hemisfério norte que, por sua vez, foram dimensionados para salmonídeos. Entretanto, a capacidade natatória das espécies migradoras, em termos de resistência e velocidade, é o principal fator a ser considerado no dimensionamento de uma passagem para peixes e estas informações ainda não são conhecidas para as espécies migradoras neotropicais. Dessa forma, o estudo da capacidade natatória das espécies neotropicais tornou-se uma necessidade. Este estudo tem como objetivo estimar as velocidades crítica, sustentável e prolongada do piau-três-pintas, Leporinus reinhardti, bem como avaliar a influência da temperatura da água na capacidade natatória. Testes de velocidade variável e fixa foram desenvolvidos em um aparato experimental do tipo respirômetro. Quando comparado a outras espécies, cujos dados de velocidade crítica são disponíveis, observa-se que o piau apresenta velocidades superiores para um mesmo comprimento total. Tempo de fadiga por classe de velocidade prolongada foram obtidos bem como a velocidade prolongada por classes de tempo de fadiga. O ponto de mudança do modo sustentável para o modo prolongado de natação foi estimado ocorrer em, aproximadamente, sete comprimentos por segundo (1.12 m/s para indivíduos com 16 cm de comprimento total: comprimento de primeira maturação). Apesar da grande capacidade natatória do piau, a adoção de critérios eficientes para o projeto de mecanismos de transposição para peixes neotropicais dependerá de análise detalhada da capacidade natatória de diferentes espécies.

The present study used fixed and increasing velocity tests in an experimental apparatus based on Brett's respirometer to examine prolonged and sustained speeds of the "mandi-amarelo", Pimelodus maculatus. When comparing the curves of critical speed versus total length between the mandi and the sockeye salmon Oncorhynchus nerka, it is observed that for an equal total length, the mandi presents a greater speed, probably due to water temperature differences. The sustained speed for the species was estimated in 5 lengths per second and the percentage of fatigued fish within time in a certain velocity was established. The data raised for the mandi represents an important contribution to the improvement of the handling of the species, providing guidance and criteria for designing several structures, such as fishways, fish screens and guidance systems.Keywords: critical speed, prolonged speed, fish passages. Capacidade natatória da espécie neotropical de água doce:Pimelodus maculatus Lacepède, 1803 ResumoNo presente estudo, foram utilizados testes de velocidade fixa e progressiva em um aparato experimental baseado no respirômetro de Brett, para examinar as velocidades prolongada e sustentável do mandi-amarelo, Pimelodus maculatus. Quando comparadas as curvas de velocidade crítica versus o comprimento do corpo entre o mandi e o salmãoOncorhynchus nerka, é observado que, para um mesmo comprimento, o mandi apresenta velocidades superiores, provavelmente devido a diferenças na temperatura da água. Foram estimadas a velocidade sustentável da espécie em cinco comprimentos por segundo e a porcentagem de peixes fatigados ao longo do tempo em uma dada velocidade estimada. Os dados obtidos para o mandi representam uma importante contribuição para o manejo da espécie, provendo critérios de projeto para a construção de estruturas como mecanismos de transposição e sistemas de proteção e orientação.Palavras-chave: velocidade crítica, velocidade prolongada, passagem de peixes.

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