https://repositorio.ufu.br/handle/123456789/18961 2026-10-09T06:20:06Z 2026-10-09T06:20:06Z https://repositorio.ufu.br/handle/123456789/50542 2026-10-07T06:20:55Z 2025-07-25T00:00:00Z

Title: Poluição por microplásticos em Patrimônios Naturais da UNESCO: do cenário global às primeiras evidências nos Lençóis Maranhenses. Abstract: Microplastic (MP) pollution has emerged as one of the primary threats to aquatic and terrestrial ecosystems, including globally recognized protected areas. This review critically evaluates MPs' presence, distribution, and impacts in regions classified as UNESCO World Natural Heritage Sites. The analysis encompasses 60 studies published up to December 2024, highlighting temporal trends and geographic gaps. Findings reveal that of the 312 UNESCO-recognized areas, only 26 have been the focus of MP-related studies, primarily in coastal and aquatic ecosystems. Notable sites include the Galápagos Islands, the Great Barrier Reef, and the Fernando de Noronha Archipelago. MPs, predominantly synthetic fibers composed of polyethylene (PE) and polypropylene (PP), were detected across various environmental matrices and organisms, including sediments, surface waters, and marine and freshwater species. Furthermore, human activities such as unregulated tourism and improper waste disposal exacerbate MP dispersion, compromising the ecological integrity of these regions. This review identifies methodological gaps and proposes more integrated approaches to enhance monitoring and mitigation efforts, emphasizing the importance of global and regional public policies. By contributing to a broader understanding of the impacts of MPs in areas of high ecological and cultural value, this study underscores the urgency of coordinated actions that balance environmental conservation with economic sustainability.

2025-07-25T00:00:00Z https://repositorio.ufu.br/handle/123456789/49544 2026-08-15T06:27:42Z 2026-07-31T00:00:00Z

Title: Metabolismo ácido das crassulaceae e absorção foliar de água: uma análise integrada de determinantes estruturais, fisiológicos e bioquímicos em plantas suculentas Abstract: Epiphytes, including many orchids and bromeliads, have evolved morphological and physiological strategies that enhance water-use efficiency in response to water deficit. Among these strategies are the presence of succulent organs, the expression of Crassulacean Acid Metabolism (CAM), and foliar water uptake (FWU). In some cases, these traits are interconnected, such as the relationship between succulence and CAM, as well as the influence of leaf succulence and cell wall composition on FWU capacity. Therefore, the central hypothesis of this thesis is that FWU is related to the circadian cycle inherent to CAM metabolism. To address this hypothesis, the thesis is organized into three chapters. In the first chapter, we hypothesized that the accumulation of organic acids associated with CAM expression reduces leaf water potential at dawn, thereby increasing FWU rates in Vanilla phaeantha. We also expected that cell wall components associated with water retention and movement, particularly pectins, would be widely distributed throughout the leaves. In the second chapter, we hypothesized that water restriction alters leaf water balance and photosynthetic activity, increasing CAM expression (i.e., promoting greater accumulation of organic acids) and consequently maximizing FWU. To test this hypothesis, drought conditions were simulated through water restriction in Cattleya forbesii and Cattleya guttata. In the third chapter, we proposed that FWU enhances water-use efficiency, promotes photosynthetic activity, and reduces oxidative stress in Puya chilensis, a species frequently exposed to fog events. Additionally, we hypothesized that fog frequency may modulate the intensity of CAM expression and influence FWU capacity. To test this, an experiment was conducted simulating artificial fog events and water deficit conditions. Overall, our results contribute to a better understanding of the water-use strategies adopted by succulent plants, such as epiphytic orchids and bromeliads, in response to fluctuations in water availability commonly experienced in the environments where they occur.

2026-07-31T00:00:00Z https://repositorio.ufu.br/handle/123456789/48920 2026-07-21T06:26:53Z 2025-07-28T00:00:00Z

Title: Predação de moluscos invasores pela ictiofauna: análise no rio Araguari e revisão na bacia hidrográfica do Paraná Abstract: The introduction of invasive mollusks into aquatic ecosystems has caused several ecological impacts, altering the structure and functioning of native communities. In the Paraná River basin, species such as Melanoides tuberculata, Corbicula fluminea, and Limnoperna fortunei have successfully established and become abundant in various habitats. This chapter presents a literature review on the occurrence of these mollusks in the diet of fish from the Paraná basin, aiming to identify predation patterns, consumer species, and potential ecological implications of incorporating exotic invertebrates into the diet of the ichthyofauna. This review considered 16 studies published between 1999 and 2025, which applied visual methods of stomach content analysis in different regions of the basin. The results show that several fish groups, especially omnivores and invertebrate feeders, include invasive mollusks in their diet, although consumption frequency varies among species, habitats, and invasion stages. L. fortunei is the most frequently recorded species, even in recently invaded areas, suggesting rapid trophic adaptation by the fish assemblage. The consistent presence of these mollusks in fish diets may indicate their integration into local food webs, with potential consequences for native population dynamics and energy flow. Although predation by fish may act as a form of natural control, it does not appear to limit the expansion of invasive mollusks, highlighting the need for integrated management strategies and further studies on the longterm trophic effects of these interactions.

2025-07-28T00:00:00Z https://repositorio.ufu.br/handle/123456789/47946 2025-12-30T06:18:14Z 2025-09-29T00:00:00Z

Title: Reabilitação da biodiversidade e funções ecológicas dos solos em agroecossistemas alto-andinos do Equador sobre Cangahua Abstract: The sustainable management of high-Andean agroecosystems relies heavily on the dynamics of soil organic carbon (SOC), microbial activity, and the maintenance of ecosystem services, particularly in soils with cangahua, a hardened volcanic material highly prone to degradation. This study synthesized the effects of diverse soil management practices—agroecological, traditional, fallow, and degraded ecosystem as control—on organic matter decomposition, carbon content, soil respiration, microbial diversity, and biogeochemical functionality across two Ecuadorian highland sites, Cacha (Chimborazo) and La Merced (Pichincha), which differ in their historical rehabilitation periods (5 versus 15 years, respectively). The methodology integrated tea bag indices (green and rooibos) to evaluate decomposition rates of labile and recalcitrant organic materials, loss-on-ignition for SOC quantification, Solvita® assays for soil respiration, and microbial community assessments through taxonomic and functional diversity metrics. Statistical analyses employed a fully factorial design with 24 experimental units, enabling detection of management, site, and interaction effects. Results consistently demonstrated that agroecological management enhanced green and rooibos tea decomposition, SOC accumulation, and soil respiration relative to traditional, fallow, and degraded systems, with La Merced exhibiting generally higher rates than Cacha, reflecting both climatic and historical management influences. Traditional and fallow practices provided intermediate benefits, insufficient to counteract long-term degradation, whereas degraded ecosystems exhibited severely reduced microbial activity, low SOC content, and diminished biogeochemical functionality, confirming functional collapse under cangahua exposure. Microbial analyses revealed that agroecological soils harbored greater taxonomic richness and functional redundancy, supporting higher nutrient cycling efficiency and resilience to perturbations. Moreover, the study found strong positive correlations between SOC content, microbial biomass, and respiration rates, indicating that sustained organic inputs, permanent ground cover, and crop diversification directly enhance soil functional capacity and carbon stabilization. Integrating these findings, the research demonstrates that systematic agroecological interventions not only rehabilitate degraded soils but also contribute to carbon sequestration and climate change mitigation in fragile mountainous landscapes. Importantly, the comparative analysis across sites and historical contexts highlights the temporal dimension of soil restoration, emphasizing that long-term implementation is critical to realizing full ecosystem benefits. In conclusion, this integrative assessment provides robust scientific evidence supporting agroecological transitions as a key strategy to restore high-Andean cangahua soils, improve soil fertility and structure, enhance microbial diversity and activity, maintain ecosystem services, and strengthen the capacity of rural communities to sustain agricultural production while contributing to global climate mitigation goals. The findings inform policy formulation, extension services, and participatory management approaches, underscoring the value of combining ecological principles with traditional practices to achieve both environmental restoration and socio-economic resilience in highly vulnerable highland territories.

2025-09-29T00:00:00Z