About 45 palm species occur in the Atlantic forest of Brazil, and most of them are affected by loss of seed dispersers resulting from forest fragmentation and hunting. Here we report the effects of habitat loss and defaunation on the seed dispersal system of an endemic palm, Astrocaryum aculeatissimum . We evaluated seed removal, insect and rodent seed predation, and scatter-hoarding in nine sites, ranging from 19 ha to 79 000 ha. We report the seedling, juvenile and adult palm densities in this range of sites. Endocarps remaining beneath the parent palm had a higher probability of being preyed upon by insects in small, mostly fragmented and more defaunated sites. The frequency of successful seed removal, scatter-hoarding and consumption by rodents increased in the larger, less defaunated sites. Successful removal and dispersal collapsed in small ( < 1000 ha), highly defaunated sites and frequently resulted in low densities of both seedlings and juveniles. Our results indicate that a large fraction of Atlantic forest palms that rely on scatter-hoarding rodents may become regionally extinct due to forest fragmentation and defaunation. Current management practices including palm extraction and hunting pressure have a lasting effect on Atlantic forest palm regeneration by severely limiting successful recruitment of prereproductive individuals.

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Defaunation has a major driver of biodiversity loss in tropical forests. Here we discuss how to reverse defaunation by re‐introducing key species in defaunated or restored forests.

A fragmentação florestal e a caça criam as chamadas "florestas vazias", onde extinções ecológicas de grandes vertebrados resultam na perda de interações entre animais e plantas como a dispersão e a predação de sementes. Alterações nesses processos afetam o recrutamento das plântulas e, consequentemente, a abundância e diversidade das plantas. As palmeiras são um dos recursos alimentares mais abundantes nos trópicos e são consideradas espécies-chave para a alimentação de várias espécies de mamíferos. A presente revisão analisou os resultados de 74 estudos conduzidos nos Neotrópicos até 2008 sobre dispersão e predação de sementes de palmeiras por mamíferos. Roedores, primatas e ungulados foram os frugívoros neotropicais que mais consumiram frutos de palmeiras, atuando como importantes dispersores de sementes. A maior parte dos estudos que investigaram os efeitos de empobrecimento de mamíferos sobre a dispersão de sementes e o recrutamento de palmeiras encontrou que as taxas e distâncias de remoção de sementes foram menores em fragmentos florestais ou locais defaunados, o que resultou em um acúmulo de sementes nas imediações das plantas-mãe nesses locais. Na maioria dos casos, esse acúmulo resultou em um aumento na predação pré-dispersão devido à maior atração de besouros brocadores, proliferação de patógenos, e/ou às altas densidades de pequenos mamíferos predadores de sementes. Devido à complexidade das interações ecológicas e dos processos que levam ao estabelecimento de novos indivíduos de plantas, houve diferentes respostas das palmeiras à defaunação, algumas delas se tornando mais escassas em pequenos fragmentos, enquanto outras espécies aumentaram suas abundâncias. Características morfológicas e ecológicas distintas permitem identificar grupos de palmeiras com diferentes vulnerabilidades à extinção e o reconhecimento desses grupos, juntamente com a predição dos cenários gerados pela fragmentação e pela defaunação, permite a implementação de estratégias adequadas de manejo. Palavras-chave: Dispersão de sementes, fragmentação de habitats, mamíferos, palmeiras, predação de sementes. ABSTRACT INTERACTIONS OF MAMMALS AND PALMS IN FRAGMENTED NEOTROPICAL LANDSCAPES. Human-induced forest fragmentation and hunting create so-called "empty forests", wherein the loss of major vertebrates results in the disruption of many animal-plant interactions, including seed dispersal and predation. Such disturbances affect recruitment of seedlings and ultimately the abundance and diversity of plants. Palm trees are one of the most abundant food resources in tropical forests and are therefore considered necessary for the survival of many mammal species. The present paper analysed the results of 74 studies in the Neotropical region (published until 2008) dealing with palm tree seed dispersal and predation by mammals.

Reintroduction is an increasingly important tool to restore local extinctions and ecological interactions. Evaluating the success of reintroduction projects allows conservationists to learn from previous experience. Here we report on the reintroduction of agoutis, Dasyprocta leporina, to a Brazilian Atlantic Forest reserve in order to (1) determine the short-term status of the reintroduction; (2) describe and evaluate the management procedures that contributed to reintroduction success; and (3) identify the fruits and seeds consumed and buried by the agoutis, as an indication of their role in restoring ecological processes. We captured and tagged 21 adult individuals from a semi-captive population and reintroduced four males and seven females. One male died and almost all individuals lost weight (range=0-620 g; n=11) during quarantine (median=133 days; range=67-243 days; n=20). Six males and three females died, but the others gained weight during acclimatization (range=150-260 g; n=5). Individuals abandoned the food supplement up to 87 days after release, establishing home-ranges at least three times larger than in natural populations of agoutis. The estimated annual survival rate was 0.83, and 10 nature-born cubs were observed. The reintroduction was considered successful in the short-term. Among the main recommendations for future reintroductions, we suggest the reduction of quarantine and the maintenance of acclimatization periods, with structural improvements for both. Agoutis were seen eating fruits and seeds of 10 species and burying seeds of three of them. The buried seeds are from zoochoric large-seeded trees, thus enhancing recruitment in a disperser-impoverished forest.Keywords: Dasyprocta leporina, frugivory, radiotracking, reintroduction, spatial patterns. Resumo A reintrodução é uma ferramenta cada vez mais importante para restaurar extinções locais e interações ecológicas. Avaliar o sucesso de projetos de reintrodução permite que conservacionistas aprendam com experiências prévias. Aqui nós reportamos a reintrodução de cutias Dasyprocta leporina em uma reserva da Mata Atlântica brasileira, objetivando (1) determinar o status da reintrodução em curto prazo, (2) descrever e avaliar os procedimentos de manejo que contribuíram para o processo de reintrodução e (3) identificar os frutos e sementes consumidos e enterrados pelas cutias, como um indicativo do seu papel na restauração de processos ecológicos. Nós capturamos e marcamos 21 indivíduos adultos originários de uma população semicativa e reintroduzimos quatro machos e sete fêmeas. Um macho morreu e quase todos perderam peso (variação=0-620 g, n=11) durante a quarentena (mediana=133 dias, variação=67-243 dias, n=20). Seis machos e três fêmeas morreram, mas os outros ganharam peso durante a aclimatação (variação=150-260 g; n=5). Os indivíduos abandonaram a suplementação alimentar em até 87 dias depois da soltura, estabelecendo áreas de vida pelo menos três vezes maiores do que as encontradas para populações naturais de cutias. A taxa de sobr...

Large-seeded plants are especially vulnerable to the loss of seed dispersers in small forest fragments. The palm Attalea humilis goes against this trend by reaching high abundances in small remnants. Productivity, seed dispersal and seed predation of A. humilis were investigated in two large (2400 and 3500 ha) and three small (19, 26 and 57 ha) Atlantic Forest fragments in southeastern Brazil. Palms in the small fragments produced more female inflorescences, resulting in a higher fruit production in these places. Seed dispersal rates were higher in the large fragments, where scatter hoarding was more frequent. Scolytine beetles were the main seed predators and damaged a larger number of seeds in small fragments, but predation by rodents and bruchine beetles was low irrespective of fragment size. As scolytines do not necessarily kill the seeds, low predation by bruchines and rodents, together with its own high productivity, allow A. humilis to be more abundant in small fragments despite the scarcity of its main dispersers. This increased abundance, by its turn, can increase competitive interactions between A. humilis and other plants in small fragments. Thus, abundance patterns of A. humilis are a good example of fragmentation affecting the balance of ecological interactions in a complex way, emphasizing the role of preserving ecological processes for conserving biodiversity in fragmented tropical landscapes.Abstract in Portuguese is available in the online version of this article.

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