Programa de Pós-graduação em Ecologia e Evolução
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Navegando Programa de Pós-graduação em Ecologia e Evolução por Por Orientador "Almeida Neto, Mário"
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Item Efeitos diretos e indiretos de características de plantas sobre a similaridade na composição de insetos herbívoros e parasitoides associados à Asteraceae(Universidade Federal de Goiás, 2018-03-15) Alvarenga, Vinícius Silva de; Almeida Neto, Mário; http://lattes.cnpq.br/1000297113793647; Almeida Neto, Mário; Santos, Carolina Moreno dos; Araújo, Walter Santos deUnderstanding how interactions between trophic levels structure species composition is one of the main goals of ecological studies. Mechanisms that explain the compositional structure of parasitoid insects usually neglect the direct and indirect effects of plants’ characteristics, which can also determine the compositional structure of their host herbivore insects. In this context, our goal was to evaluate how plants’ characteristics (abundance, floral phenology, and phylogenetic distance) and herbivores’ compositional similarity determine parasitoids’ compositional similarity. As study system, we used Asteraceae species, flower-head feeding insects, and parasitoids. Using path analysis, we considered parasitoids and herbivores’ similarities, in qualitative (Sørensen similarity), quantitative (Bray-Curtis similarity), and phylogenetic proximity (taxonomic Sørensen similarity) terms. In general, we demonstrated that herbivores’ similarity is the major predictor of parasitoids’ similarity. Even though the effects of plants’ characteristics explained the smallest part of the variation in parasitoids’ similarity, these characteristics had inconsistent relative importance among the similarity indexes used here. Thus, our results indicate that although plant species constitute a potential additional barrier for the parasitoids of endophagous herbivores to find their insect hosts, herbivore parasitoids in flower heads of Asteraceae do not see the plant species in this way. The parasitoids respond mainly to the compositional variation of their insect hosts in the plant species that the latter consume. Therefore, we show how the composition of the upper trophic levels in this tri-trophic system is structured directly and indirectly by antagonistic interactions.Item A importância das plantas e dos herbívoros hospedeiros na especialização dos parasitoides de afídeos(Universidade Federal de Goiás, 2021-08-30) Bergamo, Norem Ceane da Silveira Barbosa; Bergamini, Leonardo Lima; http://lattes.cnpq.br/7657432431796954; Almeida Neto, Mário; http://lattes.cnpq.br/1000297113793647; Almeida Neto, Mário; Baumgartner, Matheus Tenório; Melo, Adriano SanchesThe variety of host organisms represents one of the most important dimensions of the ecological niche of parasitoids and parasites in general. In the case of insect parasitoids that attack herbivores, the degree of specialization of these in the use of hosts can be determined by cues and restrictions imposed by herbivores and by their host plants. We used plant-aphid-parasitoid interactions sampled from several regions of the globe to investigate the specialization in the use of aphids and plants by parasitoid. Specifically, we aim to answer the following questions: (1) which trophic level, plants or herbivores, exerts greater influence on parasitoid specialization? (2) how important is the scale of network, regional or global, for specialization patterns? We found phylogenetic specialization of the parasitoids toward both aphids and plants, with specialization toward aphids being greater when compared to specialization toward plants. As for the effect of spatial scale, specialization was more evident when evaluated on a global scale than on a regional scale, especially for plants. These results reinforce the importance of coevolutionary history in the interactions between parasitoids and aphids, and also demonstrate the mediation role of plants in determining the interactions between parasitoids and host herbivores.Item Efeito do isolamento filogenético sobre a riqueza e composição de insetos herbívoros em plantas exóticas(Universidade Federal de Goiás, 2015-03-20) Grández Rios, Julio Miguel; Almeida Neto, Mário; http://lattes.cnpq.br/1000297113793647; Almeida Neto, MárioThe replacement of native plants by introduced or invasive exotic plants may have significant impacts on the fauna of herbivorous insects. These impacts can occur both directly, through changes in reproductive success and population size herbivorous insects that consume the exotic plants, and indirectly through changes in the availability of native host plants. This study is divided into two parts. In the first chapter, I evaluated the effect of phylogenetic isolation on the richness and composition of species of herbivorous insects on exotic plants. In addition, I also examined possible differences in response to phylogenetic isolation of exotic plants between herbivore assemblages made up exclusively of endophagous and exophagous insects.In the second chapter, I evaluated the effect of phylogenetic isolation of host plants on the mean specialization of herbivorous insects fauna associated with host plants. In addition,I also analyzed the effect of phylogenetic isolation of host plants differs between native and exotic plants. Taken together, the results of the two chapters exemplify how the richness, composition and specialization of herbivores respond to phylogenetic isolation of their host plants.Item Padrões biogeográficos da especialização e distribuição de insetos herbívoros(Universidade Federal de Goiás, 2020-03-25) Mamede, Angélica Francisca Mendes; Almeida Neto, Mário; http://lattes.cnpq.br/1000297113793647; Araújo, Walter Santos de; Nabout, João Carlos; Cunha, Hélida Ferreira da; Santos, Carolina Moreno dos; Almeida Neto, MárioSome studies have questioned the theory that species are more specialized in biotic interactions in tropical regions. On the other hand, there are an increasing number of studies including biotic interactions to understand the distribution of species and their responses to climate change. Species distribution can be affected by factors linked to their ecological niche. However, biotic interactions are often associated with small spatial scales, while environmental conditions are associated with the distribution of species on a biogeographic scale. Using interaction networks compiled from the literature, I sought to understand: (i) the effect of different measures of specialization on the detectability of the relationship between latitude and feeding specialization of herbivorous insects; (ii) how the latitudinal distribution of frugivorous flies (Tephritidae) in the Americas is related to the specialization in the use of host plants and climatic seasonality; (iii) how climate change can alter the distribution of species of frugivorous flies of the genus Anastrepha spp. (modeled considering abiotic and biotic factors) and how the degree of specialization in plants can influence species responses to climate change. We found that secondary factors, related to the data sets, and not the difference in calculating the different indexes of specialization affected the specialization of herbivorous insects. Additionally, we observed no evidence of a relationship between the latitude and specialization of herbivorous insects after estimating different specialization indexes using the same data set. We also show that fruit flies species that occur at higher latitudes have smaller distribution ranges, thus contradicting the expectation according to the Rapoport effect. The breadth of latitudinal distribution were explained by the width of the feeding niche, seasonality in precipitation and the species origin (being native or introduced). Finally, we find that the Anastrepha fruit flies from the American continent will have their distributions increased as a result of climate change and this increase is related to the degree of specialization in host plants.Item Diversidade beta e estrutura de interações em redes inseto-planta do cerrado(Universidade Federal de Goiás, 2018-03-15) Martins, Lucas Pereira; Almeida Neto, Mário; http://lattes.cnpq.br/1000297113793647; Carvalheiro, Luísa Gigante; Araújo, Walter Santos deUnderstanding how species interact with each other is essential to advance our knowledge on community ecology. However, there are still gaps regarding how interspecific interactions affect and are affected by the variation in the composition of species that constitute the ecological networks. In particular, studies of beta diversity are interesting to understand how sets of biotic filters may affect species’ geographic distribution and persistence on communities. Another interesting question is if variations in species composition may cause changes on how ecological networks are structured. In this dissertation, we propose to evaluate patterns of beta diversity and structure on insect-plant interaction networks. Specifically, in the first chapter we aimed to test if beta diversity is affected by the trophic level to which the assemblage belongs, and by the degree of specialization of species at higher trophic levels to their host species. For this, we used a tritrophic system comprising plants of the family Asteraceae, endophagous herbivores and parasitoids sampled in remnants of Brazilian Cerrado. Our main results show that total beta diversity of parasitoids (higher trophic level) was lower than those of the other trophic levels, while there was no difference between total beta diversity of plants and herbivores. Furthermore, the degree of specialization of the assemblages of herbivores and parasitoids was positively associated to the beta diversity of these groups. In the second chapter, we evaluated if species beta diversity among sites affects dissimilarity in network structure, and if this relationship changes across time. Overall, the relationship between spatial beta diversity and dissimilarity in plant-herbivore network structure was context-dependent, thus indicating that different ecological processes (i.e., niche-based and neutral) may drive the organization of antagonistic networks across time.Item Avaliação da importância de vertebrados e invertebrados carniceiros na dinâmica local e global de remoção de carcaças de vertebrados(Universidade Federal de Goiás, 2022-08-16) Rocha, Joedison dos Santos; Carvalheiro, Luisa Mafalda Gigante Rodrigues; http://lattes.cnpq.br/2611280969164348; Almeida Neto, Mário; http://lattes.cnpq.br/1000297113793647; Almeida Neto, Mário; Nabout, João Carlos; Lopes, Welinton Ribamar; Bini, Luis Mauricio; Carlucci, Marcos BergmannVertebrate carcasses compose the pool of dead organic matter in the ecosystems, highlighting as a food resource for a plethora of living organisms, from microorganisms to large vertebrates. A decomposition island is established when a vertebrate dies, altering the nutrient inputs and diversity of microorganisms in the soil, as well as the composition of plant communities. Scavenger animals (invertebrates and vertebrates) are responsible for recycling nutrients from carcasses, thus preventing dead animals from accumulating in natural environments. Therefore, scavengers act both in the large-scale distribution of nutrients and in sanitation and ecosystem health. Despite this, there are several gaps regarding how these scavenger groups affect the dynamics of carcass removal and their effects on ecosystem functioning. Even basic information such as which species are involved in the removal process is scarce in the literature. The present thesis aimed to elucidate the local and global importance of vertebrate and invertebrate scavengers for: a) removal efficiency; b) nutrient cycling; and c) disease control in vertebrate carcasses, as well as d) interactions between both groups. First, an experiment using caged and uncaged carcasses (n=16) was conducted in a well-conserved Cerrado area to test the effect of loss of vertebrate actions on removal time and nutrient inputs to the soil. After 10 days, all carcasses were removed by vultures and invertebrates, without difference between treatments, suggesting that invertebrates can compensate for the absence of vertebrates. Also, the experiment showed that potassium and magnesium inputs increase in the soil around carcasses when vertebrates are absent. Besides the typical scavenger species (necrophagous flies and vultures), carcasses were largely visited by opportunistic or facultative species (e.g. wasps, butterflies, and mammals). From two global systematic reviews, we observed that the complementary activity of vertebrates and invertebrates ensures high removal efficiency compared to carcasses removed experimentally in the absence of vertebrates. Furthermore, vertebrate communities that are highly efficient in removing carcasses are typically composed of few species (<10 spp.) and higher proportion of birds. This result highlighted the functionally unique contribution provided by vultures and crows across the world. Finally, based on a model relating scavenger vertebrates to cases of zoonoses, a higher prevalence of anthrax was associated with a high diversity of facultative scavengers (e.g. eagles and mammalian carnivores), but not with the richness of vultures. Thus, the study demonstrated that vertebrate diversity represents an important factor in carcass removal efficiency. However, invertebrates can outperform vertebrate functions in certain contexts, as observed in the Cerrado. The actions of both groups affect the rates of nutrient inputs from carcasses to the soil, while partially affecting the spread of zoonoses around the world.Item Efeito de plantas exóticas sobre a fidelidade de polinizadores e a qualidade do serviço de polinização(Universidade Federal de Goiás, 2014-02-25) Valente, Cristiele Barbosa; Almeida Neto, Mário; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4737911T2; Almeida Neto, Mário; Franceschinelli, Edivani Villaron; Torres, Marina WolowskiThe invasion of terrestrial habitats by exotic plants often has negative effects on growth and fitness of native plants. Exotic plants may change the foraging behavior of pollinators and dynamics of interactions of local assemblages. Due to the lack of shared evolutionary history between exotic plants and native pollinators, it is likely that the morphological and phenological mismatches are especially important in determining the interactions involving exotic plants and specialist native pollinators. In addition, exotic plant species are expected to be pollinated by abundant generalist pollinators whose interactions are phylogenetically constrained compared to specialists pollinators. To evaluate these issues, we compiled 28 plant-pollinator networks with 778 plant species (10% alien) and 3019 pollinator species, comprising 7919 interactions. We expected that: (a) exotic plants tend to be visited by more generalist pollinator species compared to the co-occurring native plant species; (b) an increase in the proportion of exotic plants in the plant-pollinator networks promotesan increase in the global connectivity and nestednessof the interactions. If these predictions are correct, then the introduction of plants should also promote an increase in the risk of heterospecific pollen deposition on native plants. We found that exotic and native plants did not differ in the average degree of specialization of their pollinators. Moreover, an increase in the proportion of alien plants did not affecteither structure or the connectivity of networks. On the other hand, there was an increase in the risk of heterospecific pollen deposition on native plant stigmas when the proportion of exotic plants increases to about 1/3 of the flora pollinated by animals.However, above this percentage the relationship is reversed. This result may be a consequence of progressive decrease in pollinator fidelity of native plants in habitats with low-levels of invasion by exotic species, reducing the amount of shared pollen due to the impoverished pollinator fauna.Item Um modelo estocástico de coextinções em redes mutualísticas(Universidade Federal de Goiás, 2014-05-09) Vieira, Marcos Costa; Almeida Neto, Mário; http://lattes.cnpq.br/1000297113793647; Lima Junior, Dilermando Pereira; Marco Júnior, Paulo De; Almeida Neto, Mário(Sem resumo em outra língua)