Os processos de dispersão, sobrevivência da prole e os períodos fenológicos das espécies vegetais, são o resultado tanto de sua história evolutiva quanto de suas adaptações ao ambiente. Para analisar o padrão evolutivo destes processos, foi testada a hipótese de que a similaridade entre espécies aparentadas em relação aos seus atributos reprodutivos (frutos, sementes e a fenologia da floração e frutificação) é maior do que o esperado por mero acaso (alto sinal filogenético), através de testes de Mantel parcial controlando o efeito da forma de vida das espécies. Os resultados revelaram que a maioria dos atributos de sementes, dois atributos dos diásporos (display das cores e a porcentagem de polpa) e o tempo de desenvolvimento dos diásporos, apresentaram um moderado sinal filogenético. Isto sugere que a conservação de atributos de sementes para sobrevivência da prole e a labilidade dos atributos de diásporos buscando dispersões mais efetivas, afetam significativamente o fitness das espécies, além de indicar uma influência do tempo de desenvolvimento dos diásporos nos picos de frutificação. / The processes of dispersal, offspring survival and phenological periods of plant species result both from their evolutionary history and adaptations to the environment. To analyze the evolutionary pattern of these processes, the hypothesis that the similarity among related species in relation to their reproductive traits (fruits, seeds and the phenology of flowering and fruiting) is higher than expected by chance (high phylogenetic signal) was tested through partial Mantel tests, controlling for the effect of species life form. The results revealed that most seed traits, two diaspores traits (color display and pulp percentage) and the time of diaspore development, show moderate phylogenetic signal. This suggests that the conservation of seed traits for offspring survival and the lability of diaspore traits seeking more effective dispersions, significantly affect the species fitness, and it also indicates the influence of the time of diaspore development on the fruiting peaks.

Os processos de dispersão, sobrevivência da prole e os períodos fenológicos das espécies vegetais, são o resultado tanto de sua história evolutiva quanto de suas adaptações ao ambiente. Para analisar o padrão evolutivo destes processos, foi testada a hipótese de que a similaridade entre espécies aparentadas em relação aos seus atributos reprodutivos (frutos, sementes e a fenologia da floração e frutificação) é maior do que o esperado por mero acaso (alto sinal filogenético), através de testes de Mantel parcial controlando o efeito da forma de vida das espécies. Os resultados revelaram que a maioria dos atributos de sementes, dois atributos dos diásporos (display das cores e a porcentagem de polpa) e o tempo de desenvolvimento dos diásporos, apresentaram um moderado sinal filogenético. Isto sugere que a conservação de atributos de sementes para sobrevivência da prole e a labilidade dos atributos de diásporos buscando dispersões mais efetivas, afetam significativamente o fitness das espécies, além de indicar uma influência do tempo de desenvolvimento dos diásporos nos picos de frutificação. / The processes of dispersal, offspring survival and phenological periods of plant species result both from their evolutionary history and adaptations to the environment. To analyze the evolutionary pattern of these processes, the hypothesis that the similarity among related species in relation to their reproductive traits (fruits, seeds and the phenology of flowering and fruiting) is higher than expected by chance (high phylogenetic signal) was tested through partial Mantel tests, controlling for the effect of species life form. The results revealed that most seed traits, two diaspores traits (color display and pulp percentage) and the time of diaspore development, show moderate phylogenetic signal. This suggests that the conservation of seed traits for offspring survival and the lability of diaspore traits seeking more effective dispersions, significantly affect the species fitness, and it also indicates the influence of the time of diaspore development on the fruiting peaks.

Os processos de dispersão, sobrevivência da prole e os períodos fenológicos das espécies vegetais, são o resultado tanto de sua história evolutiva quanto de suas adaptações ao ambiente. Para analisar o padrão evolutivo destes processos, foi testada a hipótese de que a similaridade entre espécies aparentadas em relação aos seus atributos reprodutivos (frutos, sementes e a fenologia da floração e frutificação) é maior do que o esperado por mero acaso (alto sinal filogenético), através de testes de Mantel parcial controlando o efeito da forma de vida das espécies. Os resultados revelaram que a maioria dos atributos de sementes, dois atributos dos diásporos (display das cores e a porcentagem de polpa) e o tempo de desenvolvimento dos diásporos, apresentaram um moderado sinal filogenético. Isto sugere que a conservação de atributos de sementes para sobrevivência da prole e a labilidade dos atributos de diásporos buscando dispersões mais efetivas, afetam significativamente o fitness das espécies, além de indicar uma influência do tempo de desenvolvimento dos diásporos nos picos de frutificação. / The processes of dispersal, offspring survival and phenological periods of plant species result both from their evolutionary history and adaptations to the environment. To analyze the evolutionary pattern of these processes, the hypothesis that the similarity among related species in relation to their reproductive traits (fruits, seeds and the phenology of flowering and fruiting) is higher than expected by chance (high phylogenetic signal) was tested through partial Mantel tests, controlling for the effect of species life form. The results revealed that most seed traits, two diaspores traits (color display and pulp percentage) and the time of diaspore development, show moderate phylogenetic signal. This suggests that the conservation of seed traits for offspring survival and the lability of diaspore traits seeking more effective dispersions, significantly affect the species fitness, and it also indicates the influence of the time of diaspore development on the fruiting peaks.

This study investigates the impact of arrival order and seed traits on plant community assembly and biodiversity in a grassland ecosystem in northern Sweden. A field experiment was conducted using 20 different grassland species, with germination pre-tests in the greenhouse and sowing experiments in the field. Seed mass and germination speed were selected seed traits to provide insights into the competitive ability and early life history strategies of the sown species. In the field study, four arrival order treatments with both slow- and fast-germinating species were performed on 70 m2 plots. After three years, the aboveground biomass of the established species was harvested and analyzed, revealing that species arriving second exhibited significantly lower biomass compared to those arriving first. Our results thereby suggest that arrival order has a significant impact on the productivity of species in grassland ecosystems. Priority effect strength (PES) was assessed using two different equations, with results indicating no significant relationship between PES and seed mass or germination speed. Biodiversity analysis revealed that plots with simultaneous late arrival had significantly lower Shannon diversity indices compared to arrival earlier in the season. These findings suggest that arrival order significantly influences plant productivity, while the effect on biodiversity in grassland ecosystems is less clear. Further, seed traits such as mass and germination speed may not play a significant role in determining the strength of priority effects during community assembly.

Orientador: Alessandra Fidelis / Resumo: No Cerrado, um dos fatores abióticos que influenciam na fenologia das plantas é o fogo, o qual é um distúrbio natural que interfere em diversos ecossistemas do mundo. O fogo altera as condições do habitat podendo afetar a floração, frutificação, atributos das sementes e germinação. Portanto, esse projeto visou compreender o efeito do fogo na fenologia reprodutiva e nos atributos de semente e germinação da comunidade do Cerrado. Para isso, foram realizadas a contagem do número de ramos (vegetativos e reprodutivos) por espécie, realizados em 30 subparcelas de 1x1m em áreas com diferentes históricos de fogo (C=6 anos sem queima e FB=recentemente queimada). Também foram marcados indivíduos de diferentes espécies dominantes em ambas as áreas. A comunidade e os indivíduos tiveram sua floração acompanhados a cada 15 dias durante 3 meses após a queima e então aos 6, 9 e 12 meses. Os seguintes atributos das sementes e germinação foram medidos: forma e peso da semente, teor de água, germinabilidade, tempo médio de germinação e sincronia. Nossos resultados mostraram que o fogo aumentou a floração nas áreas queimadas. Já nos primeiros 30 dias até 3 meses após a queima houve até 2 vezes mais espécies que floresceram nas áreas FB comparados a C. Também houve um aumento significativo na proporção de ramos reprodutivos aos 3 meses pós-fogo na comunidade, mostrando que a profusão reprodutiva ocorre nos primeiros meses após queima. Dentre as espe... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In Cerrado one of the abiotic factors that influences plant phenology is fire, which is a natural disturbance that interferes with several ecosystems in the world. Fire changes the conditions of the habitat and can affect flowering, fruiting and seeds and germination traits. Therefore, this project aimed to understand the effect of fire on reproductive phenology and on seed and germination traits of Cerrado community. For this purpose, the counting of the number of branches (vegetative and reproductive) by species was carried out in 30 subplots of 1x1m in areas with different fire histories (C = 6 years without burning and FB = recently burned). We also marked individuals of different dominant species in both areas. The community and individuals had their flowering counted every 15 days for 3 months after burning and then at 6, 9 and 12 months. The following seed and germination traits were measured: seed shape and mass/weight, water content, germinability, mean germination time and synchrony. Our results showed that fire increased flowering in burned areas. Already after 30 days up to 3 months after the burning there were up to 2-fold more species flowering in the FB areas compared to C. There was also a significant increase in the proportion of reproductive shoots at 3 months post-fire in the community, showing that the reproductive profusion occurs in the first few months after burning. Among the species of the community 66.39% can be considered stimulated by fire. Seed an... (Complete abstract click electronic access below) / Mestre

Despite extensive international acceptance of the critical role of mammalian post-dispersal seed predation in many plant communities, in New Zealand we have limited knowledge of these predators’ influence on plant recruitment in our forests. The principle objective of my thesis was to determine the importance of exotic mammals as post-dispersal seed predators in a New Zealand conifer-broadleaf forest remnant. To address this goal, I used a series of field-based experiments where the actions of different post-dispersal seed predators were separated by wire-mesh exclosures. My study was conducted at Mount Peel Forest Park Scenic Reserve, South Canterbury, New Zealand. Being a human modified conifer forest currently dominated by broadleaf species, it is typical of forest remnants in New Zealand. This presented an opportunity to study a wide range of both potential post-dispersal seed predators and broadleaf tree species. My findings indicate that exotic mammals are not only post-dispersal seed predators at Peel Forest, but are responsible for the majority of post-dispersal predation events observed. Ship rats (Rattus rattus) were the dominant post-dispersal seed predators, while brushtail possums (Trichosurus vulpecula), house mice (Mus musculus) and native invertebrates were also important post-dispersal seed predators for several tree species. Through use of time-lapse video and cafeteria experiments I found that exotic mammalian seed predators, when compared to native invertebrate seed predators, preyed upon larger-seeded plant species and were responsible for considerable seed losses of several tree species. However, exotic mammalian seed predators do share several foraging characteristics with native invertebrate seed predators, as predators foraged in similar habitats and responded in a similar way to changes in seed density. In investigating if post-dispersal seed predation by mammals had a flow-on effect to plant recruitment, I observed natural seedling densities at Peel Forest were significantly higher in the absence of mammalian seed predators, but I found no evidence that the presence of mammals significantly altered the overall species richness. At the community level, I did not find an interaction between habitat and exotic mammals, however I present evidence that for individual plant species a significant mammal : habitat interaction occurred. Consequently, even though my cafeteria experiment implied there was no significant difference in the overall amount of seed preyed upon within different habitats, the less favourable microsite conditions for germination under an intact continuous canopy allows mammals to exacerbate habitat-related patterns of seed mortality and have a noticeable effect on seedling establishment. In an effort to validate the use of manipulative experiments to predict the long-term effect of post-dispersal seed predation on plant dynamics, I attempted to link results of my cafeteria experiment with observed seedling abundance at Peel Forest. Seven tree species were used in this comparison and a strong correlation was observed. This result shows that the level of post-dispersal seed predation determined in the cafeteria experiment provided a good predictor of the effect of mammalian post-dispersal seed predation on seedling establishment. To fully gauge the impact of mammalian post-dispersal seed predators on seedling establishment, the relationship between these seed predators and the type of recruitment limitation experienced by a plant species was also investigated. By using a combination of seed addition, plot manipulations and seed predator exclusion I was able to investigate this relationship. I found evidence that seed limitation at Peel Forest is positively correlated with seed size, and that while mammalian post-dispersal seed predators can further reduce plant recruitment of plant species experiencing seed limitation, the influence of mammals in determining plant recruitment was limited for plant species experiencing microsite limitation. My study has proven that exotic mammals are now the dominant post-dispersal seed predators at Peel Forest, the amount of seed preyed upon varies among plant species, and post-dispersal seed predation by mammalian species can lead to differences in seedling richness and abundance. I proved that the influence of exotic mammals on seedling establishment is also linked to habitat structure and recruitment limitations. When combined these observations suggest that exotic mammalian post-dispersal seed predators may play an important role in determining landscape abundance and distribution of plants at Peel Forest.