The destruction of tropical forests is the most concerning current threat to biodiversity. Although protected areas have long been used as the primary tool for biodiversity conservation, there is an increasing need to find suitable conservation strategies for the growing area of human-modified land. This thesis addresses three themes that have been identified as the most pressing areas for research in human-modified landscapes: biodiversity conservation beyond protected areas, forest restoration, and the human–environment relationship. By studying the interactions between birds, plants, and people with isolated Ficus (Moraceae) trees in Assam, India, this thesis reports several important findings: 1) isolated Ficus trees are extraordinarily important to frugivorous bird communities that inhabit human-modified landscapes; 2) the frugivores visiting these isolated trees still sustained the majority of ecological function found in trees close to the forest edge; 3) isolated Ficus trees are also exceptionally important feeding sites for insectivorous birds in human-modified landscapes, compared to other trees; 4) Ficus trees are better restoration nuclei than other isolated trees; 5) although the sacred status of Ficus trees in Assam has a major influence on their abundance and distribution, faith-based values are insufficient in ensuring their conservation. In conclusion, this thesis finds that isolated Ficus trees are critically important micro-sites for conservation in human-modified landscapes, the loss of which may lead to avifaunal collapse and a reduction in restoration potential. However, by stressing their ecological and cultural properties, it may be possible to build a strong case for the conservation of isolated Ficus trees in Assam and elsewhere.

Frugivorous insects, specialised herbivores that consume fruit and seeds, are considered detrimental to host plant fitness. Their direct link to genetic fitness via consumption of plant reproductive tissue, and their negative socioeconomic association with agriculture exacerbates their harmful status. However, empirical testing of insect frugivore effects on host plants, and ecological research on the contribution of insect frugivores to multitrophic frugivory systems, is lacking. In the current study, direct effects of a non-mutualistic, insect frugivore/host plant system were tested and results showed variable effects. Beneficial, detrimental, but predominantly neutral effects on germination and seed production were observed between the Queensland fruit fly (Bactrocera tryoni) and tomato and capsicum plants. Significant effects on seed production were unexpected because infestation occurs after seed set. It was also found that eggplant, although a recorded host of B. tryoni, is inconsistent in its ability to sustain B. tryoni larvae through to its final instar. These results confirmed a simplification and presumption associated with insect frugivore (specifically fruit fly)/host plant interactions. Larval movement, infestation-induced fruit decay, pulp removal and germination were then investigated. For all hosts (tomato, apple and paw paw), treatments infested by B. tryoni decayed significantly quicker and to a greater extent than uninfested treatments, with obvious but variable changes to the texture and appearance. The movement of B. tryoni larvae, pattern of infestation-induced decay and pulp removal was unique and host dependent for all hosts. Only seeds from infested tomato were shown to germinate during the experiment. This indicated that host fruit characteristics are responsible, in part, for variable direct effects on host plant fitness by insect frugivores. Variable direct effects between insect frugivores and host plants, combined with the more rapid decay of infested fruits is likely to have implications for seed dispersal and seed predation by a third trophic level. The characteristics of fruit that are changed by infestation by an insect frugivore were then tested for their effect on a vertebrate frugivore, to illustrate the importance of recognising multitrophic interactions and indirect effects in frugivory. Specifically, seed predating rodents were incorporated into the study and their response to infested and uninfested fruits were recorded, as well as their reaction to the changes in fruit caused by insect frugivores (i.e. texture, smell, larvae presence and sound). Apple and pear infested with B. tryoni larvae were found to attract rodents, while infested tomato and paw paw had a neutral effect on the native rats. This differed from the predominant finding in the literature, which was a deterrent effect on avian seed dispersers. Vertebrate response to fruit infested with insect frugivores therefore, is variable. Assessing the indirect effect of insect frugivores on host plant fitness by attracting or deterring another trophic level requires knowledge of the direct effect between the introduced trophic level and the host plant. For example, the attraction of a seed predator may be as detrimental to host plant fitness as the deterrence of a seed disperser. This illustrates the complexity associated with assessing insect frugivore effects on host plant fitness. Results also indicated that differences in pulp texture, caused by infestation, have a significant effect on rodent preference for infested or uninfested treatments. Pulp texture is likely to effect rodent foraging efficiency, whereas the presence of B. tryoni larvae was observed to be inconsequential to rodent response to fruits. For rodents, and indeed any trophic level motivated by foraging efficiency, this finding raises the issue that for long lived fruiting plants, outside factors such as food abundance and competition for food, may cause a variable response to fruits infested by insect frugivores. From these investigations it has become apparent that insect frugivores are not consistently harmful to host plant fitness, as suggested by their negative stigma, but are likely to contribute variable effects, directly and indirectly, on multiple components of plant fitness and multitrophic frugivory systems.

A resposta da fauna à fragmentação e perda de hábitat pode variar amplamente segundo os requerimentos ecológicos, a configuração da paisagem, a conectividade e as pressões antrópicas. Os morcegos são bons candidatos para trabalhar os efeitos da fragmentação na fauna mas, mesmo assim, existem poucos estudos a respeito da diversidade dos morcegos frugívoros e sua dieta em áreas de cerrado do estado de São Paulo e nas demais áreas de cerrado do país, tendo em conta que este bioma vem sofrendo processos de mudança muito rápidos nas últimas décadas. Assim, vimos a importância de incorporar este grupo de fauna nos estudos que tem sido desenvolvidos na região. Durante 48 dias de coleta ao longo de um ano (2012), procurou-se inventariar a quiropterofauna de dois fragmentos de Cerrado correspondentes à Estação Ecológica de Jataí e ao Cerrado Pé-do-Gigante, nos municípios de Luiz Antônio e Santa Rita do Passa Quatro, localizados ao noroeste do Estado de São Paulo, sendo amostradas fisionomias diferentes: cerradão, cerrado sensu stricto, cerrado adensado e cerrado em estado de regeneração. Foram realizadas duas coletas mensais, de 4 horas cada, iniciadas após o pôr do sol, totalizando 24 amostragens em cada unidade de conservação. Os morcegos foram coletados com redes de neblina situadas a 50 cm do solo, em trilhas preexistentes e em áreas abertas, e identificados em nível de espécie. Outros dados ecológicos, como frequência, dominância, riqueza, constância, horário de atividade, dieta, dispersão de sementes através das fezes dos indivíduos capturados e a influência da luminosidade lunar foram analisados. Foram capturados e anilhados 195 indivíduos de 3 famílias e 7 subfamílias, pertencentes a 17 espécies diferentes, sendo 113 na estação chuvosa e 82 na estação seca. Na E.E. Jataí foram capturados 118 indivíduos de 15 espécies e, no Cerrado Pé-do-Gigante, 77 indivíduos, de 13 espécies, com um esforço amostral de de 31680 m². O índice de Shannon-Wiener apresentou uma diferencia sutil entre a diversidade de espécies em ambas as unidades de Conservação, constatada também pelo alto índice de similaridade de Sorensen (0,75). Obtiveram-se 5 recapturas, uma delas confirmando o fluxo entre unidades de conservação. As espécies dominantes foram: Artibeus lituratus, Anoura caudifer, Sturnira lilium, Glossophaga soricina e Carollia perspicillata. Com relação à dispersão de sementes, obtiveram-se 39 amostras de fezes, das quais 11 continham sementes que posteriormente foram germinadas em laboratório, obtendo-se assim 9 espécies de plantas petencentes a 4 gêneros, potencialmente dispersadas pela quiropterofauna local / The response of wildlife to fragmentation and habitat loss may vary widely according to the ecological requirements, landscape configuration, connectivity among landscape units, and anthropogenic pressures. Bats are ideal species to study fragmentation effects on wildlife, however, studies on the diversity of frugivore bats and their diet in savanna biomes are scarce, despite the intense changes linked to human pressures this biome has been recently submitted to. Therefore, we considered relevant to incorporate the evaluation of the regional bat assembly to fauna studies in Cerrado areas of São Paulo state. During a period of 48 days, representative of both rainy and dry seasons of 2012, we surveyed chiropterofauna in two Cerrado fragments, in the northwestern Sao Paulo state: Jataí Ecological Station (Luiz Antônio municipality) and Cerrado Pé-do-Gigante (Santa Rita de Passa-Quatro municipality). These units show different physiognomies: cerradão, cerrado sensu stricto, dense cerrado and cerrado in regeneration. The surveys were carried out under two nights per month in each conservation area. Bats were collected using mist nets located 50 cm above ground in existing trails in open areas. A total of 195 individuals belonging to 3 families, 7 subfamilies and 17 species were captured and ringed: 113 of these during the rainy season and the remaining 82 during dry season. In E.E. Jataí we registered 118 individuals belonging to 15 species, and in Cerrado Pé-do-Gigante, 77 individuals from 13 species (31680 m² of mist net in the two fragments of Cerrado). Most of the individuals recorded during the study belong to 5 species: Artibeuslituratus, Anoura caudifer, Sturnira Lilium, Glossophaga soricina and Carollia perspicillata. In relation to seed dispersion, 39 fecal samples were obtained, of these, 11 contained seeds that later were germinated in laboratory, obtaining nine species of plants of 4 geners potentiality dispersed by the local bats

Spatial variation in tree community composition and assembly is due in large part to dispersal limitation, spatial variation in environmental conditions, and interactions among competing trees. The relative importance of these processes may be governed by landscape structure and environmental conditions. (I) The movement of frugivores between remnant forests and successional areas is vital for tropical forest tree species to colonize successional habitats. I found that avian frugivores crossing forest edges were generally insensitive to percent cover and clustering of pasture trees. If pastures were abandoned the distance from forest edges would not likely limit frugivore visitation and seed deposition under pasture trees in my study. (II) Relatively little is known from a theoretical conservation perspective about how reserve size affects communities assembled by abiotic and dispersal limitations. Simulated small reserve systems increased the distance between environments dominated by different species, diminishing the importance of source-sink dynamics. I found a trade-off between preserving different aspects of natural communities, with greater [alpha]-diversity in large reserves and greater [gamma]-diversity across small reserve systems. (III) Functional trait diversity of co-occurring organisms may be indicative of the processes that structure communities. Across spatial scales, an axis of leaf succulence exhibited the strongest evidence for niche-based assembly among co-occurring Ficus individuals, whereas specific leaf area (SLA) showed the strongest evidence for niche-based assembly among species. Trait analyses of co-occurring individuals had greater power than analyses at the species level, especially for traits with high intraspecific variation. Environmental filtering may be stronger at higher elevations due to drought stress. (IV) Individual fitness is a function of the interaction between traits and environment, or environmental selection. I estimated spatial selective gradients affecting a subtropical tree community and found that the trait axes with the strongest selection were also those with the least spatial variation. Interestingly, factors associated with selection were quite different for growth versus survivorship. The trait-by-environment interactions I identified are strong candidates for spatial niche differentiation, and may explain how tree species coexist in this diverse subtropical forest. / text

A resposta da fauna à fragmentação e perda de hábitat pode variar amplamente segundo os requerimentos ecológicos, a configuração da paisagem, a conectividade e as pressões antrópicas. Os morcegos são bons candidatos para trabalhar os efeitos da fragmentação na fauna mas, mesmo assim, existem poucos estudos a respeito da diversidade dos morcegos frugívoros e sua dieta em áreas de cerrado do estado de São Paulo e nas demais áreas de cerrado do país, tendo em conta que este bioma vem sofrendo processos de mudança muito rápidos nas últimas décadas. Assim, vimos a importância de incorporar este grupo de fauna nos estudos que tem sido desenvolvidos na região. Durante 48 dias de coleta ao longo de um ano (2012), procurou-se inventariar a quiropterofauna de dois fragmentos de Cerrado correspondentes à Estação Ecológica de Jataí e ao Cerrado Pé-do-Gigante, nos municípios de Luiz Antônio e Santa Rita do Passa Quatro, localizados ao noroeste do Estado de São Paulo, sendo amostradas fisionomias diferentes: cerradão, cerrado sensu stricto, cerrado adensado e cerrado em estado de regeneração. Foram realizadas duas coletas mensais, de 4 horas cada, iniciadas após o pôr do sol, totalizando 24 amostragens em cada unidade de conservação. Os morcegos foram coletados com redes de neblina situadas a 50 cm do solo, em trilhas preexistentes e em áreas abertas, e identificados em nível de espécie. Outros dados ecológicos, como frequência, dominância, riqueza, constância, horário de atividade, dieta, dispersão de sementes através das fezes dos indivíduos capturados e a influência da luminosidade lunar foram analisados. Foram capturados e anilhados 195 indivíduos de 3 famílias e 7 subfamílias, pertencentes a 17 espécies diferentes, sendo 113 na estação chuvosa e 82 na estação seca. Na E.E. Jataí foram capturados 118 indivíduos de 15 espécies e, no Cerrado Pé-do-Gigante, 77 indivíduos, de 13 espécies, com um esforço amostral de de 31680 m². O índice de Shannon-Wiener apresentou uma diferencia sutil entre a diversidade de espécies em ambas as unidades de Conservação, constatada também pelo alto índice de similaridade de Sorensen (0,75). Obtiveram-se 5 recapturas, uma delas confirmando o fluxo entre unidades de conservação. As espécies dominantes foram: Artibeus lituratus, Anoura caudifer, Sturnira lilium, Glossophaga soricina e Carollia perspicillata. Com relação à dispersão de sementes, obtiveram-se 39 amostras de fezes, das quais 11 continham sementes que posteriormente foram germinadas em laboratório, obtendo-se assim 9 espécies de plantas petencentes a 4 gêneros, potencialmente dispersadas pela quiropterofauna local / The response of wildlife to fragmentation and habitat loss may vary widely according to the ecological requirements, landscape configuration, connectivity among landscape units, and anthropogenic pressures. Bats are ideal species to study fragmentation effects on wildlife, however, studies on the diversity of frugivore bats and their diet in savanna biomes are scarce, despite the intense changes linked to human pressures this biome has been recently submitted to. Therefore, we considered relevant to incorporate the evaluation of the regional bat assembly to fauna studies in Cerrado areas of São Paulo state. During a period of 48 days, representative of both rainy and dry seasons of 2012, we surveyed chiropterofauna in two Cerrado fragments, in the northwestern Sao Paulo state: Jataí Ecological Station (Luiz Antônio municipality) and Cerrado Pé-do-Gigante (Santa Rita de Passa-Quatro municipality). These units show different physiognomies: cerradão, cerrado sensu stricto, dense cerrado and cerrado in regeneration. The surveys were carried out under two nights per month in each conservation area. Bats were collected using mist nets located 50 cm above ground in existing trails in open areas. A total of 195 individuals belonging to 3 families, 7 subfamilies and 17 species were captured and ringed: 113 of these during the rainy season and the remaining 82 during dry season. In E.E. Jataí we registered 118 individuals belonging to 15 species, and in Cerrado Pé-do-Gigante, 77 individuals from 13 species (31680 m² of mist net in the two fragments of Cerrado). Most of the individuals recorded during the study belong to 5 species: Artibeuslituratus, Anoura caudifer, Sturnira Lilium, Glossophaga soricina and Carollia perspicillata. In relation to seed dispersion, 39 fecal samples were obtained, of these, 11 contained seeds that later were germinated in laboratory, obtaining nine species of plants of 4 geners potentiality dispersed by the local bats

As palmeiras figuram entre as espécies vegetais mais importantes aos animais, já que seus frutos são bastante nutritivos e estão disponíveis geralmente em épocas de escassez de alimentos. Uma gama de animais alimentam-se de seus frutos, incluindo aves, morcegos, mamíferos não voadores, répteis, peixes e insetos. As palmeiras com frutos grandes apresentam, entretanto, limitação na dispersão de suas sementes, pois apenas poucas espécies animais podem atuar como dispersoras. As florestas tropicais vêm sofrendo da chamada “síndrome de florestas vazias", onde interações mutualísticas e agonísticas entre animais e plantas já foram perdidas, pela ausência de dispersores e predadores de sementes e herbívoros de grande porte. O primeiro capítulo teve como objetivo verificar os frugívoros que dispersam e predam as sementes da palmeira brejaúva, Astrocaryum aculeatissimum, bem como avaliar as proporções de predação das sementes por invertebrados e o recrutamento de plântulas próximos às plantas-mãe. No segundo capítulo foi avaliado o efeito da defaunação, relacionado a abundância de cutias, na remoção e na distância de dispersão das sementes. A predação por invertebrados e o recrutamento de plântulas e jovens ao redor da planta mãe também foram comparados em cinco áreas na Mata Atlântica com diferentes abundâncias de cutias. As hipóteses testadas foram que as áreas com baixas abundâncias de cutias apresentariam uma menor remoção das sementes, uma maior predação por invertebrados e um menor recrutamento de plântulas. Além das cutias (Dasyprocta spp.), ratos de espinho (Trynomis iheringi) e esquilos (Sciurus aestuans) também foram os responsáveis pela remoção de sementes e atuaram mais como dispersores do que predadores nos cinco dias de exposição das sementes. A massa das sementes não mostrou relação com a remoção pelas espécies animais. Sementes mais pesadas foram levadas a maiores distâncias da planta-mãe e as sementes predadas foram levadas a maiores distâncias do que as sementes dispersas. As áreas mais defaunadas mostraram uma menor porcentagem de remoção de sementes, bem como de predação e dispersão. A proporção de endocarpos predados por vertebrados foi maior na área com maior abundância de cutias (Ilha Anchieta) e as proporções de endocarpos intactos e predados por invertebrados foram maiores na área com menor abundância (Xixová Japuí). O recrutamento de plântulas embaixo das plantas-mãe amostradas não mostrou diferença significativa entre as áreas. O número de plântulas de Astrocaryum aculeatissimum nos 0,8 ha amostrados em cada área foi maior na Ilha do Cardoso, onde há também uma alta densidade de cutias e o menor recrutamento foi encontrado em Xixová Japuí, a área mais defaunada. Como a espécie estudada não é dispersa por uma grande diversidade de frugívoros, mudanças sutis na composição faunística do local podem ter efeitos cruciais na população da brejaúva a longo prazo. O estudo mostrou que o decréscimo populacional de cutias diminui a remoção, a predação e a dispersão de sementes, aumenta a proporção de sementes predadas por invertebrados embaixo das plantas-mãe, diminuindo o recrutamento das plântulas de Astrocaryum aculeatissimum. / The palms are among the most important plant species to the animals, because their fruits are nutritive and are available in periods of fruit scarcity. Lots of animals feed on palm fruits, including birds, bats, non-volant mammals, reptiles, fishes and insects. The palm species with big fruits show, however, limitation in seed dispersal because only a few animal`s species can act as dispersers. The tropical forest has suffered the “Empty Forest Syndrome", where mutualistic and agonistic interactions between animals and plants have just gone due to the absence of seed dispersers and predators and large size herbivores. The first chapter has as an objective study the frugivores responsible to disperse and predate the seeds of the palm brejaúva Astrocaryum aculeatissimum and evaluate the proportion of seed predation by invertebrates and the seedling recruitment close to the mother-plant. In the second chapter, the defaunation effect was evaluated, related to the agoutis’ abundance, on the removal and on the seed dispersal distance. The seed predation by invertebrates and the seedling and juvenile recruitment near the mother-plant were compared in five study sites with different agoutis`abundance. The principal hypothesis was that in areas with low agoutis’ abundance, the seed removal and the seedling recruitment were lower and the seed predation by invertebrates were higher. Besides agoutis (Dasyprocta spp.), spiny rats (Trynomis iheringi) and squirrels (Sciurus aestuans) were also responsible for the seed removal and acted more as seed dispersers than seed predators, during the five days of the experiment. The seed mass didn`t show relation with the seed removal by each of the animal species. Heavier seeds were carried to long distances, and the predated seeds were carried longer than the dispersed seeds. The most defaunated study site showed less seed removal, seed dispersal and seed predation. The proportion of seed predation by vertebrates was higher in study site with higher agoutis` abundance (Ilha Anchieta) and the proportion of intacts endocarps and predated by invertebrates were higher in the study site with less agoutis’ abundance (Xixová Japuí). The seedling recruitment near the mother plant didn`t show difference among the areas. The number of Astrocaryum aculeatissimum seedlings in the 0,8 hectares sampled in each area was higher at Ilha do Cardoso, where we have a high agoutis’ abundance and the smaller recruitment was found in Xixová Japuí, the more defaunated area. The study showed that the decrease in agoutis` population, decrease the Astrocaryum aculeatissimum seed removal, dispersal and predation and increase the seed predation by invertebrates, decreasing the seedling recruitment.

As palmeiras figuram entre as espécies vegetais mais importantes aos animais, já que seus frutos são bastante nutritivos e estão disponíveis geralmente em épocas de escassez de alimentos. Uma gama de animais alimentam-se de seus frutos, incluindo aves, morcegos, mamíferos não voadores, répteis, peixes e insetos. As palmeiras com frutos grandes apresentam, entretanto, limitação na dispersão de suas sementes, pois apenas poucas espécies animais podem atuar como dispersoras. As florestas tropicais vêm sofrendo da chamada “síndrome de florestas vazias”, onde interações mutualísticas e agonísticas entre animais e plantas já foram perdidas, pela ausência de dispersores e predadores de sementes e herbívoros de grande porte. O primeiro capítulo teve como objetivo verificar os frugívoros que dispersam e predam as sementes da palmeira brejaúva, Astrocaryum aculeatissimum, bem como avaliar as proporções de predação das sementes por invertebrados e o recrutamento de plântulas próximos às plantas-mãe. No segundo capítulo foi avaliado o efeito da defaunação, relacionado a abundância de cutias, na remoção e na distância de dispersão das sementes. A predação por invertebrados e o recrutamento de plântulas e jovens ao redor da planta mãe também foram comparados em cinco áreas na Mata Atlântica com diferentes abundâncias de cutias. As hipóteses testadas foram que as áreas com baixas abundâncias de cutias apresentariam uma menor remoção das sementes, uma maior predação por invertebrados e um menor recrutamento de plântulas. Além das cutias (Dasyprocta spp.), ratos de espinho (Trynomis iheringi) e esquilos (Sciurus aestuans) também foram os responsáveis pela remoção de sementes e atuaram mais como dispersores do que predadores nos cinco dias de exposição das sementes. A massa das sementes não mostrou relação com a remoção pelas espécies animais. Sementes mais pesadas foram levadas a maiores distâncias da planta-mãe e as sementes predadas foram levadas a maiores distâncias do que as sementes dispersas. As áreas mais defaunadas mostraram uma menor porcentagem de remoção de sementes, bem como de predação e dispersão. A proporção de endocarpos predados por vertebrados foi maior na área com maior abundância de cutias (Ilha Anchieta) e as proporções de endocarpos intactos e predados por invertebrados foram maiores na área com menor abundância (Xixová Japuí). O recrutamento de plântulas embaixo das plantas-mãe amostradas não mostrou diferença significativa entre as áreas. O número de plântulas de Astrocaryum aculeatissimum nos 0,8 ha amostrados em cada área foi maior na Ilha do Cardoso, onde há também uma alta densidade de cutias e o menor recrutamento foi encontrado em Xixová Japuí, a área mais defaunada. Como a espécie estudada não é dispersa por uma grande diversidade de frugívoros, mudanças sutis na composição faunística do local podem ter efeitos cruciais na população da brejaúva a longo prazo. O estudo mostrou que o decréscimo populacional de cutias diminui a remoção, a predação e a dispersão de sementes, aumenta a proporção de sementes predadas por invertebrados embaixo das plantas-mãe, diminuindo o recrutamento das plântulas de Astrocaryum aculeatissimum. / The palms are among the most important plant species to the animals, because their fruits are nutritive and are available in periods of fruit scarcity. Lots of animals feed on palm fruits, including birds, bats, non-volant mammals, reptiles, fishes and insects. The palm species with big fruits show, however, limitation in seed dispersal because only a few animal`s species can act as dispersers. The tropical forest has suffered the “Empty Forest Syndrome”, where mutualistic and agonistic interactions between animals and plants have just gone due to the absence of seed dispersers and predators and large size herbivores. The first chapter has as an objective study the frugivores responsible to disperse and predate the seeds of the palm brejaúva Astrocaryum aculeatissimum and evaluate the proportion of seed predation by invertebrates and the seedling recruitment close to the mother-plant. In the second chapter, the defaunation effect was evaluated, related to the agoutis’ abundance, on the removal and on the seed dispersal distance. The seed predation by invertebrates and the seedling and juvenile recruitment near the mother-plant were compared in five study sites with different agoutis`abundance. The principal hypothesis was that in areas with low agoutis’ abundance, the seed removal and the seedling recruitment were lower and the seed predation by invertebrates were higher. Besides agoutis (Dasyprocta spp.), spiny rats (Trynomis iheringi) and squirrels (Sciurus aestuans) were also responsible for the seed removal and acted more as seed dispersers than seed predators, during the five days of the experiment. The seed mass didn`t show relation with the seed removal by each of the animal species. Heavier seeds were carried to long distances, and the predated seeds were carried longer than the dispersed seeds. The most defaunated study site showed less seed removal, seed dispersal and seed predation. The proportion of seed predation by vertebrates was higher in study site with higher agoutis` abundance (Ilha Anchieta) and the proportion of intacts endocarps and predated by invertebrates were higher in the study site with less agoutis’ abundance (Xixová Japuí). The seedling recruitment near the mother plant didn`t show difference among the areas. The number of Astrocaryum aculeatissimum seedlings in the 0,8 hectares sampled in each area was higher at Ilha do Cardoso, where we have a high agoutis’ abundance and the smaller recruitment was found in Xixová Japuí, the more defaunated area. The study showed that the decrease in agoutis` population, decrease the Astrocaryum aculeatissimum seed removal, dispersal and predation and increase the seed predation by invertebrates, decreasing the seedling recruitment.

South Africa is one of the world's most biologically invaded countries and has spent billions of rands on efforts to eradicate alien invasive plants. Chemical and mechanical control methods have varied in success and the need for integrated management strategies has been realised. This requires a better understanding of all aspects of the invasion process. Some of the most invasive plant species rely on vertebrate dispersers which facilitate long-distance seed dispersal. Frugivory is based on a mutualism in which the frugivores gain a resource and the plants benefit from seed dispersal away from the parent plant. Seed germination itself may either be enhanced, reduced or not affected at all after gut passage. The first aim of this study was to determine if generalist avian frugivores and a fruit bat species (Epomophorus wahlbergi) enhance or decrease seed germination of invasive alien plants in South Africa, by either pulp removal or seed coat abrasion, or if they serve as dispersers only. The second aim was to determine if avian frugivores are able to meet their energetic demands by feeding on a specific alien fruit diet. Finally, we also quantified the nutritional content and morphological characteristics of fleshy fruits of various invasive alien and exotic plant species. Avian frugivores: Red-winged Starlings (Onychognathus morio), Speckled Mousebirds (Colius striatus), and Dark-capped Bulbuls (Pycnonotus tricolor), varied in their effects on the germination success of seeds of four invasive alien species, namely: Lantana camara, Solanum mauritianum, Cinnamomum camphora, and Psidium guajava. However, this was not associated with differences in seed retention times. Similar germination success was observed for avian ingested and de-pulped seeds. This was also observed for fruit bat spat and depulped seeds of Psidium guajava, Melia azedarach, Eriobotrya japonica, and Morus alba. Therefore seed coat abrasion was not important for the germination of these fleshy-fruited invasive alien plants. Pulp removal resulted in significantly earlier seed germination as well as higher seed germination percentages than in the case of whole fruit controls for some of these invasive species. Gut passage is thus important for long-distance dispersal, and in some cases, for enhanced germination of seeds. The invasive Solanum mauritianum and indigenous congener S. giganteum showed similar germination responses, with both ingested and depulped seeds germinating profusely. However, S. giganteum benefited from pulp removal as seeds from whole fruits had less germination. Avian frugivores varied significantly in most energetic parameters calculated when given diets of invasive alien fruit. Speckled Mousebirds and Dark-capped Bulbuls were able to maintain body mass and efficiently process fruits of all four alien invasive plants, while Red-winged Starlings were only able to do so on lipid-rich C. camphora and sugar-rich S. mauritianum. Furthermore, frugivores also adjusted their feeding behavior by eating more nutritionally poor fruit and less energetically rewarding fruit. Fruit bats consumed more fruit per gram body mass than avian frugivores did. They therefore process proportionately more seeds than avian dispersers and thus their role in invasive seed dispersal, which has previously been underestimated particularly in South Africa, is highlighted. Fruits of invasive plant species were similar in morphology, but greater in nutritional content, than fruits of indigenous species. These fruits also contained small, light seeds with approximately only 30% having more than 10 seeds per fruit. The ability of frugivores to efficiently process these fruits and the greater nutritional rewards offered by these provide new insights into why these invasive fruits are preferred by frugivores. In addition, invasive alien plants may have a competitive edge over indigenous species because of their larger reproductive outputs and not necessarily because of greater germination success. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

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