DSpace Coleção:http://repositorio.ufc.br/handle/riufc/3322026-04-10T19:55:37Z2026-04-10T19:55:37ZAtividade e diversidade da biota do solo em agroecossistemas regenerativos e convencionaisSilva, Hugo Felipe dahttp://repositorio.ufc.br/handle/riufc/857662026-04-10T18:22:10Z2026-01-01T00:00:00ZTítulo: Atividade e diversidade da biota do solo em agroecossistemas regenerativos e convencionais
Autor(es): Silva, Hugo Felipe da
Abstract: Sustainability of agroecosystems requires changes in agricultural practices that integrate soil
biodiversity as a central component, with regenerative (conservationist) practices representing
an alternative for coffee production systems. In this context, the present study evaluated
biological diversity and its association with coffee production systems under conventional,
organic and regenerative management, in areas with contrasting levels of yield: low (LY: 2,148-
3,372 kg ha⁻¹) and high (HY: 2,520-5,360 kg ha⁻¹) in the Cerrado. In this study, indicators of
soil microbiota, carbon (C) and nutrients were evaluated, as well as metataxonomic analyses of
bacteria and fungi. In addition, soil fauna was assessed using pitfall traps during the dry and
rainy seasons. Conventional management showed higher microbial activity and β-glucosidase
activity, as well as greater microbial biomass and microbial quotient, whereas regenerative
management showed higher urease activity. Bacterial richness in the rhizosphere was higher
under conventional management compared with regenerative management and was greater than
that observed in Cerrado vegetation and in bulk soil. In contrast, fungal richness and soil
macrofauna were higher in natural vegetation, and regenerative management showed greater
soil fauna richness than conventional management, which presented the lowest diversity values.
With regard to coffee yield under regenerative management, high positive correlation
coefficients were found between yield and the microbial quotient, acid phosphatase activity and
the rhizosphere C:N ratio, as well as between the Z score of surface soil biological activity and
the rhizosphere effect. Conversely, yield showed high negative correlation coefficients with
soil carbon and nitrogen contents and with labile carbon. Areas with lower yield showed
reduced fungal richness in the rhizosphere and in bulk soil, whereas increased yield was
associated with denser and more connected networks, in contrast to the pattern observed for
bacterial networks. Differences in yield levels were also reflected in soil fauna, with higher
richness and diversity of arthropods and greater abundance of predators (Opiliones and
Araneae), and lower abundance of Formicidae, in areas of high coffee yield. Biodiversity
(bacteria, fungi and arthropods) was affected by management and was associated with higher
and lower levels of coffee yield in the Cerrado.
Tipo: Tese2026-01-01T00:00:00ZEfeito do uso e ocupação do solo sobre as variáveis limnológicas e a composição da comunidade em um rio intermitenteDuarte, Maria Rita Nascimentohttp://repositorio.ufc.br/handle/riufc/853982026-03-18T16:49:46Z2022-01-01T00:00:00ZTítulo: Efeito do uso e ocupação do solo sobre as variáveis limnológicas e a composição da comunidade em um rio intermitente
Autor(es): Duarte, Maria Rita Nascimento
Abstract: The consequences of human activities on water resources have had repercussions on theway and quality of life of populations and communities of aquatic organisms, affectingthe environmental balance of areas drained by hydrographic basins, thus contributing tochange their landscapes at local scales, regional and global. The Intermittent rivers arecharacteristic for their flow variability, due to alternations between the two extremes offlow, flooding and drying, which create complex mosaics of dry channels and lenticwaters. Intensive land use raises concerns about the threats posed by anthropogenichydrological changes to the ecological integrity of intermittent rivers. Given the context,our study aims to assess how land use and occupation influence limnological variablesand the composition of communities in an Intermittent River. In chapter 1, we evaluatedthe dynamics of the physical, chemical and biological variables of the waters of anintermittent river and of an artificial surface reservoir through multivariate analysis andin response to the use and occupation of the soils of its hydrographic basin. The studywas carried out in the Cruxati River watershed in four study areas (three river areas andone artificial reservoir) and the images were obtained from the Landsat-8 satellite OLIsensor. The limnological variables measured were: pH, electrical conductivity, dissolvedoxygen, turbidity, nutrients (total nitrogen and total phosphorus) and chlorophyll a.Limnological variables were analyzed using Principal Component Analysis - PCA,Tukey's test and Cluster Analysis. The eutrophication of the studied areas was calculatedusing the Trophic State Index. The PCA allowed the selection of three componentsindicating the quality of surface water, river and artificial reservoir, explaining 88.57%of the total variance. The limnological variables responsible for the grouping were:electrical conductivity; dissolved oxygen and turbidity. The use and occupation of thesoil influenced the water quality of the river stretches. Anthropization influenced thedissolved oxygen content and the presence of arable areas caused an increase in turbidity.However, the most conserved landscape (artificial reservoir) was the one with the highestdegree of eutrophication due to the difference in hydrological dynamics between lenticand lotic environments. In chapter 2, evaluated the historical effects of land use andoccupation on limnological variables and the composition of aquatic macroinvertebratesand fish in six Intermittent microbasins. For this purpose, land use and land cover mapswere made, as watersheds 4, 5 and 6 have been going through a process of intensedeforestation and an increase in non-vegetated and agricultural areas, adding an alert tothe compromise of environmental quality and to the management of water resources inthe semi-arid region.
Tipo: Tese2022-01-01T00:00:00ZModelagem de distribuição da herpetofauna nos brejos de altitude do setor setentrional do semiárido brasileiro a partir do pleistoceno superiorHolanda, Alyne Bezerra Tabosa dehttp://repositorio.ufc.br/handle/riufc/850712026-03-04T19:59:50Z2025-01-01T00:00:00ZTítulo: Modelagem de distribuição da herpetofauna nos brejos de altitude do setor setentrional do semiárido brasileiro a partir do pleistoceno superior
Autor(es): Holanda, Alyne Bezerra Tabosa de
Abstract: The Brazilian semi-arid region, which encompasses the Caatinga biome, is situated betweentwo humid biomes—the Amazon Rainforest and the Atlantic Forest—and is characterized bythe occurrence of isolated humid environments that constitute important habitats for the localherpetofauna. This region experienced climatic shifts during the Quaternary, which influencedthe spatial distribution of humid forests. The present study examined the distribution ofherpetofaunal species groups adapted to humid enclaves within the Brazilian semi-arid regionusing species distribution modeling, focusing on the Last Interglacial (~120 ka), the LastGlacial Maximum (~22 ka), and the Mid-Holocene (~6 ka). Paleoclimatic data obtained fromWorldClim 1.4 were employed in the analyses. The models demonstrated strong discriminatoryperformance for the variables associated with each taxonomic group (maximum temperatureof the warmest month for lizards and snakes, and annual precipitation for anurans), in additionto high rainfall totals, which were relevant for all groups. Amphibians exhibited a greaterdependence on humid ecosystems, with their distributions being markedly affected during drierperiods. Lizards and snakes, in contrast, showed higher ecological tolerance, resulting inbroader distributions under these drier climatic scenarios. Overall, species distributionscontracted by approximately 35% (lizards) to 61% (snakes) during the Last Interglacial,whereas amphibians experienced a reduction of 73% relative to their current distribution.
Tipo: Tese2025-01-01T00:00:00ZEfeito da variabilidade ambiental na história evolutiva das angiospermas do semiárido brasileiroPaiva, Aparecida Barbosa dehttp://repositorio.ufc.br/handle/riufc/809162025-05-20T14:37:19Z2025-01-01T00:00:00ZTítulo: Efeito da variabilidade ambiental na história evolutiva das angiospermas do semiárido brasileiro
Autor(es): Paiva, Aparecida Barbosa de
Abstract: The structuring of biological communities results from the dynamic interaction of multiple factors,such as speciation, dispersal, extinction, ecological interactions, and environmental filtering.However, most studies on these processes adopt isolated approaches, emphasizing either ecologicalmechanisms or historical processes. Integrating these perspectives remains a crucial challenge forunderstanding the factors shaping biodiversity. In this thesis, we aim to advance this understandingthrough two chapters that investigate the taxonomic and phylogenetic diversity patterns of woodyspecies in the Caatinga, analyzing how environmental variables, such as climate and soil, along withbiogeographic processes, influence the structuring of these communities. In the first chapter, weexplore the climatic and edaphic predictors that determine the diversity of woody species in thethree main geological substrates of the Caatinga (crystalline, karstic, and sedimentary). We alsoexamine the connections between these diversity patterns and adjacent areas of the Cerrado andAtlantic Forest, investigating the role of geomorphological landscapes in the diversification of theCaatinga’s woody flora. We calculated phylogenetic alpha diversity and taxonomic andphylogenetic beta diversity patterns for both woody and herbaceous species, considering theinfluence of climatic and edaphic variables. The results indicated that among the factors analyzed,only temperature significantly influenced the phylogenetic alpha diversity of herbaceous species. Incontrast, taxonomic and phylogenetic beta diversity were influenced by variables such as pH, cationexchange capacity, temperature, and precipitation. Furthermore, our findings revealed that diversityin the crystalline, karstic, and sedimentary substrates of the Caatinga is more similar among themthan to adjacent areas of the Cerrado and Atlantic Forest, highlighting the ecological uniqueness ofthe biome. In the second chapter, we adopted a phylogenetic approach to investigate how diversitypatterns relate to present and future projected climate conditions. Using different phylogeneticmetrics, we identified that both current and short-term future climate scenarios positively influencephylogenetic endemism. Additionally, we found that centers of neoendemism are associated withmilder conditions, such as lower temperatures and reduced precipitation seasonality, while centersof paleoendemism are linked to hotter and more seasonal conditions. These patterns suggest thathistorical events and long-term climatic variations have played a central role in the formation ofthese areas of endemism. The findings of this thesis emphasize the importance of integratinghistorical and ecological aspects to understand the mechanisms shaping the biodiversity of theCaatinga. Furthermore, they reinforce the potential of phylogenetic diversity as a tool for identifyingecologically significant areas and guiding conservation strategies, highlighting the need to preservekey regions for maintaining the biome’s biodiversity.
Tipo: Tese2025-01-01T00:00:00Z