The expansion of mesquite (Prosopis velutina) in southeastern Arizona and attempts to control or remove mesquite have been well documented. However, removal of woody plants may affect the distribution and quantities of nutrient resources within soil including changes in carbon (C) and nitrogen (N) cycling and changes in the amounts of C and N sequestered in these soils. We hypothesized that mechanical mesquite removal would alter soil microclimate and nutrient inputs, leading to changes in soil C and N cycling and microbial communities and activities.This study was conducted at two separate semi-arid grassland sites south of Tucson, AZ during a three-year period. There were six study plots at each site, three plots from which mature mesquite trees had been mechanically removed and three plots where mature mesquite trees were left intact. We measured the soil temperature and moisture, C and N pools, N2O and CO2 fluxes, N mineralization rate, and microbial resistance and resilience to determine if short term changes in any of these parameters were taking place.No significant differences in N mineralization rate or microbial resistance or resilience were found between the soils under intact mesquite and from plots where mesquite had been mechanically removed. Soil temperature was not statistically analyzed because temperature was taken in only one plot per treatment and without within-treatment replicates, t-tests could not be performed. Statistically significant differences in soil moisture, total soil C and N, microbial biomass C and N, heterotrophic plate counts, and CO2 and N2O fluxes were found between treatments on different dates throughout the experiment. Despite this finding of some significant differences between treatments for some parameters measured, no recognizable pattern of changes was observed during this study. Over the course of the experiment, the data did not support our overall hypothesis, that short term changes in microclimate following mesquite removal would alter soil C and N cycling and microbial communities and activities.

Dysfunctional rangelands lose nutrients and material faster than they capture or create them. The objective of this study was to determine the effectiveness of contour furrows, drill seeding, and aeration treatments in capturing overland flow, concentrating resources, and establishing perennial bunch grasses to convert dysfunctional semiarid rangeland to a functional rangeland. The site, located on the Edwards Plateau in west Texas, USA, had bare, structurally crusted soils with sparse short-grasses (Scleropogon brevifolius). The site had a low infiltration rate contributing to excess overland flow and loss of nutrients, organic matter, and soil. Contour furrows were installed with varying intra-furrow distances (0.6 to 61 m) and then broadcast seeded to determine if furrow spacing would produce a vegetative response. Portions of the intra-furrow areas were aerated and drill seeded. All seed mixes contained warm season, perennial bunch grasses (Bouteloua curtipendula, Leptochloa dubia, and Setaria leucopila). Soil beneath furrows had greater soil water content (p-value < 0.05) than intra-furrow areas. Furrow plots had greater density of seeded grasses and total vegetation (19 individuals m-2 and 191 individuals m-2, respectively) than intra-furrow plots (0 individuals m-2 and 89 individuals m-2, respectively). This study supports other findings that suggest 1.5 m to 1.8 m is optimum intra-furrow spacing. Vegetative responses to drill seeding and aeration treatments were insignificant. Observations suggest that contour furrows are effective at establishment and support of perennial vegetation by capturing and retaining water that otherwise would be lost to runoff from untreated soil.

Dysfunctional rangelands lose nutrients and material faster than they capture or create them. The objective of this study was to determine the effectiveness of contour furrows, drill seeding, and aeration treatments in capturing overland flow, concentrating resources, and establishing perennial bunch grasses to convert dysfunctional semiarid rangeland to a functional rangeland. The site, located on the Edwards Plateau in west Texas, USA, had bare, structurally crusted soils with sparse short-grasses (Scleropogon brevifolius). The site had a low infiltration rate contributing to excess overland flow and loss of nutrients, organic matter, and soil. Contour furrows were installed with varying intra-furrow distances (0.6 to 61 m) and then broadcast seeded to determine if furrow spacing would produce a vegetative response. Portions of the intra-furrow areas were aerated and drill seeded. All seed mixes contained warm season, perennial bunch grasses (Bouteloua curtipendula, Leptochloa dubia, and Setaria leucopila). Soil beneath furrows had greater soil water content (p-value < 0.05) than intra-furrow areas. Furrow plots had greater density of seeded grasses and total vegetation (19 individuals m-2 and 191 individuals m-2, respectively) than intra-furrow plots (0 individuals m-2 and 89 individuals m-2, respectively). This study supports other findings that suggest 1.5 m to 1.8 m is optimum intra-furrow spacing. Vegetative responses to drill seeding and aeration treatments were insignificant. Observations suggest that contour furrows are effective at establishment and support of perennial vegetation by capturing and retaining water that otherwise would be lost to runoff from untreated soil.

No description available.

Submitted by admin tede (tede@pucgoias.edu.br) on 2017-02-23T17:40:05Z No. of bitstreams: 1 MARLE ARAÚJO LUZ DE CARVALHO.pdf: 1280783 bytes, checksum: 5a05220787d6bfa01b155b4519142f85 (MD5) / Made available in DSpace on 2017-02-23T17:40:05Z (GMT). No. of bitstreams: 1 MARLE ARAÚJO LUZ DE CARVALHO.pdf: 1280783 bytes, checksum: 5a05220787d6bfa01b155b4519142f85 (MD5) Previous issue date: 2016-08-11 / The objective of this study was to analyze the characteristics and profiles of prenatal care from the perspective of women treated in the primary care network in a city of Piauí semiarid region. This is a descriptive exploratory survey study with a sample of 50 pregnant women, involving six teams of the Family Health Strategy, which data collection was carried out from January to May 2016 through a questionnaire. For statistical analysis we used descriptive statistics and the chi-square test or G when n <20. The results showed that 66% of pregnant women living in urban areas. The service was characterized by single hospital that performed the delivery, which is responsible for hosting 88% of pregnant women, and 56% were treated at one clinic in the city. Access to prenatal 44% of them occurred through referral and consultation schedule in 68% of cases was through the community health worker. The sociodemographic profile was formed by the prevalence of 40% of pregnant women aged 21-30 years old, 68% declared the brown race, 46% with higher education seven years, focusing on the lowest rate in the countryside, 72% They claimed to have stable partner and 74% defined the Catholic religion. The socioeconomic profile demonstrates composed majority of 66% with occupancy of the home, 72% with family income from 0 to 1 minimum wage, 50% dependent on the Bolsa Família, 56% without children, 36% live with their spouse and 44% own their own homes . Although 70% of pregnant women have access to treated water, there are problems related to basic sanitation: 80% do not have sewage system, 88% do not reside in asphalted local, 74% do not live close to the squares and 60% reside in wooded site. Regarding habits 78% do not exercise, 96% do not smoke, do not drink alcohol 100% and 90% did not use other drugs. It was found that 68% had laboratory tests and 62% exams ultrasound properly, 74% had prenatal booklet filled properly, and 82% started the consultation in the first trimester of pregnancy. The satisfaction index regarding professional consulting physician and nursing was high, with 96% and 98% respectively. However, 64% did not participate in educational activities offered by the service, 78% had no suggestions for improvement and 90% said they did not miss any service. It was found that the variable education had an influence only on four criteria: type of delivery, abortion, suggestions and dental care. It was found that the Piauí semiarid region is a very favorable scenario, as a result of health indicators, restricted network services and low population's quality of life, the study of prenatal care characteristics, both the social and economic problems listed, as the old problem involving the climate issue in the region. / O objetivo deste trabalho consistiu em analisar as características e perfis da assistência pré-natal na perspectiva de mulheres atendidas pela rede de atenção básica de um município do semiárido piauiense. Trata-se de um estudo survey descritivo-exploratório, com amostra de 50 gestantes, envolvendo seis equipes da Estratégia Saúde da Família, cuja coleta de dados foi realizada no período de janeiro a maio de 2016, através da aplicação de questionário. Para análise estatística dos dados utilizou-se estatística descritiva, além do teste qui-quadrado ou teste G, quando n<20. Os resultados demonstraram que 66% das gestantes residem na zona urbana. O serviço foi caracterizado por único hospital que realizava o parto, o qual é responsável por acolher 88% das gestantes, sendo que 56% foram atendidas no único ambulatório da cidade. O acesso ao pré-natal de 44% delas ocorreu por meio de encaminhamento e o agendamento da consulta em 68% dos casos foi através do agente comunitário de saúde. O perfil sociodemográfico foi formado pela prevalência de 40% das gestantes na faixa etária de 21 a 30 anos, 68% se declararam da etnia parda, 46% com escolaridade maior de sete anos, concentrando-se o menor índice na zona rural, 72% afirmaram ter parceiro estável e 74% se definiram da religião católica. O perfil socioeconômico demonstra maioria composta de 66% com ocupação do lar, 72% com renda familiar de 0 a 1 salário mínimo, 50% dependentes do Bolsa Família, 56% sem filhos, 36% moram com o cônjuge e 44% possuem casa própria. Embora 70% das gestantes tenham acesso à água tratada, existem problemas relacionados ao saneamento básico: 80% não possuem rede de esgoto, 88% não residem em locais asfaltados, 74% não moram próximas às praças e 60% não residem em local arborizado. Em relação aos hábitos 78% não praticam exercício físico, 96% não fumam, 100% não ingerem álcool e 90% não consomem outras drogas. Identificou-se que 68% realizaram os exames laboratoriais e 62% os exames de ultrassonografia de forma adequada, 74% possuíam o cartão da gestante preenchido adequadamente, sendo que 82% iniciaram a consulta no primeiro trimestre de gestação. O índice de satisfação em relação à consulta do profissional médico e de enfermagem foi alto, sendo de 96% e 98% respectivamente. Porém, 64% não participaram de atividades educativas oferecidas pelo serviço, 78% não apresentaram sugestões de melhoria e 90% afirmaram não faltar nenhum serviço. Verificou-se que a variável escolaridade exerceu influência apenas em quatro quesitos: tipo de parto, aborto, sugestões e atendimento odontológico. Constatou-se que o semiárido piauiense é um cenário bastante propício, em decorrência dos indicadores de saúde, restrita rede de serviços e baixa qualidade de vida da população, ao estudo das características da atenção pré-natal, tanto pelos problemas sociais e econômicos elencados, como pela velha problemática que envolve a questão climática na região.

In this research, I describe the use of false rings to reconstruct local histories of seasonal drought in riparian ecosystems in semiarid regions. In tree-ring analysis, false rings are boundary-like features often formed as a response to drought within the growing season. Drought can be a common feature in hydrologic regimes of dryland rivers but in recent decades drought has been intensifying due to climate change and increasing water use by cities, agriculture and industry. Identifying when and where water availability has decreased along the river course is critical for understanding, and therefore managing, these generally endangered ecosystems. The higher density of trees compared to instrumental data make them ideal candidates for reconstructing site-specific drought patterns.The first part of this dissertation is an observational study conducted on the San Pedro River in southeastern Arizona during 2002. I used dendrometer data and local hydrological data to show that a period of negligible radial growth in cottonwood during the middle of the growing season coincided with a channel drying event. Tree-ring core samples confirmed that false-rings had formed in each of the instrumented trees. The second part of this dissertation is an experimental study designed to evaluate the effect of different levels of water stress on false-ring formation in cottonwood and willow. I showed that experimental decreases in water availability for periods as short as ten days were enough to induce false-ring formation in willow. Longer periods of reduced water availability were generally required to induce false-ring formation in cottonwood. In the final part of this dissertation, I reconstructed false-ring occurrence in Fremont cottonwoods at three sites along the San Pedro River. I infer from false-ring frequencies that the severity of summer drought has been increasing over the last four to six decades but that the drought severity varies along a hydrological gradient. Overall, the findings in this body of research confirm that false rings in riparian tree species can be used as indicators of seasonal drought and underscore the importance of identifying site-specific responses to reduced water availability along the riparian corridor.

Precipitation, more than any other environmental factor, controls patterns of ecosystem production and biogeochemical cycling in arid and semiarid environments. Growing-season rains in these regions are highly unpredictable as they come in intermittent pulses varying in size, frequency and spatial extent, thereby producing unique hydrological patterns that constrain the location and residence time of soil water available for biological activity. In order to understand how arid and semiarid ecosystems respond to inputs of precipitation within the context of ecosystem science and global change studies, knowledge is needed on how plants and other organisms respond as an integrated system to such environmental control. The focus of my research was to understand how the distribution of precipitation events influences the dynamics of carbon cycling in semiarid ecosystems. At a semiarid riparian woodland, measurements of CO2 exchange and evapotranspiration revealed that following precipitation events occurring soon after prolonged dry periods the efficiency of rain-use (amount of carbon gain per unit of precipitation over a specific period time) was low. Precipitation did not readily stimulate primary productivity, water was mainly lost as soil evaporation and large respiratory CO2 effluxes were observed. This commonly observed features in seasonally dry ecosystems might have profound consequences for the seasonal and annual carbon balance. In this woodland, 47% of the precipitation within a single growing season (May-October) was returned to atmosphere as soil evaporation and the CO2 efflux observed just during the first rainy month (July) was equivalent to almost 50% of the net carbon gain observed over the six-month growing season. Results from experimental irrigations in understory plots of riparian mesquite woodland revealed that the magnitude and duration of the large CO2 fluxes occurring soon after rainfall was higher in plots located under tree canopies where, relative to intercanopy plots, the amount of plant litter was higher, soil evaporation and plant photosynthetic rates were lower. Efficiency of rain-use in semiarid ecosystems during the growing season apparently was determined by the degree of coupling between gross photosynthesis and ecosystem respiration, by the fraction of precipitation lost as soil evaporation and by the water-use efficiency of the component vegetation.

Submitted by Socorro Pontes (socorrop@ufersa.edu.br) on 2016-11-10T13:16:58Z No. of bitstreams: 1 MarialdoSC_DISSERT.pdf: 2590642 bytes, checksum: 095ef28e7ca2841fc84541491e5f6234 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-01-24T14:31:49Z (GMT) No. of bitstreams: 1 MarialdoSC_DISSERT.pdf: 2590642 bytes, checksum: 095ef28e7ca2841fc84541491e5f6234 (MD5) / Approved for entry into archive by Socorro Pontes (socorrop@ufersa.edu.br) on 2017-02-03T13:13:47Z (GMT) No. of bitstreams: 1 MarialdoSC_DISSERT.pdf: 2590642 bytes, checksum: 095ef28e7ca2841fc84541491e5f6234 (MD5) / Made available in DSpace on 2017-03-21T15:06:20Z (GMT). No. of bitstreams: 1 MarialdoSC_DISSERT.pdf: 2590642 bytes, checksum: 095ef28e7ca2841fc84541491e5f6234 (MD5) Previous issue date: 2016-05-12 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The union and the exchange of knowledge between the peasantry and the academy are very important tools for environmental studies, proper management of agroecosystems and the inclusion of technologies adapted to semi-arid conditions. The aim of this study was to describe morphologically the soil and classify it according to Ethnopedological studies in the Family Agricultural Production Unit Canto da Ilha de Cima, São Miguel do Gostoso (RN). Participatory research was conducted from January to December 2015. In the exploratory phase of the research were carried out field activities, meetings and workshops in the community involving farmers, technicians, students and teachers. In the soil classification study the emic [local] and the etic [academic] knowledges were used. Eight soil profiles were excavated in five different areas of the production unit (grazing of sheep and goats, beekeeping area, agroecological cultivation of vegetables, preserved caatinga and conventional production area - the area called Old Chica). In the emic [local] classification prevailed the impressions and qualitative analyzes of morphological and physical properties of soil in an objective and inteperative way through the light of ethnopedology. Farmers classified the lands as good land, piebald ox earth and old chica land as the most important in terms of fertility for crops, differentiating those from the arisco [a sandy soil] and the piçarro [a muddy-stony soil] lands. In the etic [academic] classification was used the Brazilian System of Soil Classification. In the etic classification were identified the Typical Carbonate Haplic Cambisols soils, YELLOW Typical Eutrophic Oxisols, RED YELLOW Typical Eutrophic Latosols, YELLOW Eutrophic Acrisols Latosols, Typical Eutrophic Haplic Cambisols Tb and Typical Carbonate Haplic Vertisols. The emic [local] and etic [academic] classifications performed in this study had a close relationship with each other, since the morphological attributes characterized from different methodological criteria contributed to affirm the importance of Ethnopedology / A união e a troca de saberes entre o campesinato e a academia são instrumentos de grande relevância para estudos de ambientes, um manejo adequado dos agroecosistemas e a inserção de tecnologias adaptados as condições do semiárido. O objetivo desta pesquisa foi descrever morfologicamente o solo e classifica-lo de acordo com os estudos etnopedológicos na Unidade de Produção Agrícola Familiar Canto da Ilha de Cima, São Miguel do Gostoso (RN). A pesquisa participativa foi realizada durante o período de janeiro a dezembro de 2015. Na fase exploratória da pesquisa foram realizadas atividades de campo, reuniões e oficinas na comunidade envolvendo os agricultores, técnicos, estudantes e professores. No estudo de classificação do solo foram utilizados os conhecimentos emicista e o eticista. Foram escavados oito perfis de solo em cinco áreas distintas da unidade de produção (pastejo de ovinos e caprinos, área de apicultura, cultivo agroecológico de hortaliças, caatinga preservada e área de produção convencional - área denominada Velha Chica). Na classificação emicista prevaleceu às impressões e análises qualitativas dos atributos morfológicos e físicos dos solos de forma objetiva e inteperativa a luz da etonopedologia. Os agricultores classificaram os solos como terra boa, terra malhada do boi e terra velha chica como as mais importantes em termos de fertilidade para o cultivo agrícola, diferenciando essas das terras de arisco e de piçarro. Na classificação eticista foi utilizado o Sistema Brasileiro de Classificação de Solos. Na classificação eticista foram identificados os solos CAMBISSOLOS HÁPLICOS Carbonáticos Típicos, LATOSSOLOS AMARELOS Eutróficos típicos, LATOSSOLOS VERMELHOS AMARELOS Eutróficos típicos, LATOSSOLOS AMARELOS Eutróficos argissólicos, CAMBISSOLOS HÁPLICOS Tb Eutróficos típicos e VERTISSOLOS HÁPLICOS Carbonáticos típicos. As classificações emicista e eticista realizadas neste estudo apresentaram estreita relação entre si, uma vez que os atributos morfológicos caracterizados a partir de diferentes critérios metodológicos contribuíram para afirmar a importância da etnopedologia / 2016-11-09

Submitted by Lucienne Costa (lucienneferreira@ufcg.edu.br) on 2018-09-11T19:57:24Z No. of bitstreams: 1 TAFNES DA SILVA ANDRADE – TESE (PPGRN) 2017.pdf: 12846482 bytes, checksum: c67b2441de336d9fe46d15963d7dfc5f (MD5) / Made available in DSpace on 2018-09-11T19:57:24Z (GMT). No. of bitstreams: 1 TAFNES DA SILVA ANDRADE – TESE (PPGRN) 2017.pdf: 12846482 bytes, checksum: c67b2441de336d9fe46d15963d7dfc5f (MD5) Previous issue date: 2017-08-11 / A seca liga os fenômenos meteorológicos e a sociedade de tal forma que sua ocorrência, quase sempre, implica em consequências sociais e econômicas negativas. É um fenômeno natural cíclico comum no Semiárido nordestino do Brasil. Sua gestão deve priorizar medidas proativas tomadas antes e durante a ocorrência das secas. Obras de infraestrutura hídrica podem auxiliar nessa gestão pois contribuem para diminuição da vulnerabilidade e consequente diminuição dos impactos da seca na região. O monitoramento é outra ferramenta fundamental nesse processo pois pode integrar sistemas de alerta e orientar o momento correto para executar ações de preparação e mitigação. Diferentes índices de seca são usados no monitoramento, e deveriam considerar não apenas os fenômenos meteorológicos, mas também as atividades econômicas significativas para a região. Tomando por base o conceito de gestão do risco, este trabalho buscou identificar as relações entre a gestão do risco e a diminuição da vulnerabilidade à seca, considerando que as obras de infraestrutura e índices de secas relacionados com as atividades econômicas regionais são chaves importantes desse processo. Como resultados podemos citar que as ações de infraestrutura hídrica contribuíram para o aumento da oferta hídrica na região, que se refletiu nas baixas vulnerabilidades a seca dos municípios mais atendidos pelo programa. E que os índices de seca VCI, VHI e SPEI, possuem potencial de uso como ferramenta para aplicação de medidas de monitoramento e gestão da seca na região em regiões semiáridas, que tem na pecuária sua principal atividade econômica. / Drought connects meteorological phenomena and society in such a way that their occurrence, almost always, implies negative social and economic consequences. It is a natural phenomenon common in the Brazilian northeastern Semiarid. Its management should focus on proactive measures taken before and during the occurrence of droughts. Water infrastructure constructions may help in this management as they contribute to decrease vulnerability and consequently reduce drought impacts. Monitoring is another fundamental tool in this process because it can integrate warning systems and guide the right time to perform preparedness and mitigation actions. Different drought index are used in monitoring, and should look not only the meteorological phenomena, but also the significant economic activities for the region. Based on the concept of risk management, this work sought to identify the relationships between risk management and the reduction of vulnerabilities to drought, considering that infrastructure works and drought indexes related to regional economic activities are important keys to this process. As a result, we can mention that water infrastructure constructions contributed to the increase in the water supply in the region, which was reflected in the low vulnerability to drought in the municipalities most served by the program. And that the drought index VCI, VHI and SPEI have potential for monitoring and management drought in the semiarid region, which has livestock as its main economic activity.

MOREIRA, Camila Campos Lopes. Valores de referência de qualidade para metais pesados em solos de mangue do Estado do Ceará: subsídios para gestão da zona costeira. 2014. 164 f. Tese (Doutorado em geografia)- Universidade Federal do Ceará, Fortaleza-CE, 2014. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-06-10T19:11:47Z No. of bitstreams: 1 2014_tese_cclmoreira.pdf: 5894644 bytes, checksum: b9a9dd0cb4f75276be42b6f65a25c89f (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-06-13T23:11:06Z (GMT) No. of bitstreams: 1 2014_tese_cclmoreira.pdf: 5894644 bytes, checksum: b9a9dd0cb4f75276be42b6f65a25c89f (MD5) / Made available in DSpace on 2016-06-13T23:11:06Z (GMT). No. of bitstreams: 1 2014_tese_cclmoreira.pdf: 5894644 bytes, checksum: b9a9dd0cb4f75276be42b6f65a25c89f (MD5) Previous issue date: 2014 / Currently, activities related to urbanization and industrialization have contributed to increased concentrations of heavy metals in different types of soil. These elements have significant toxicity and can accumulate in the environment, configuring serious risk to human health and ecosystems in general. Thus, there is an increasing concern among countries in adopting an efficient environmental policy and, thus, the determination of natural concentration (background levels) of metals in soils and the consequent establishment of Quality Reference Values (QRV) are reality in some countries, including Brazil. However, there is a lack of studies like these related to soils under mangrove forests in the country, where these areas play very important roles and services in the environment. In this context, the contamination of mangrove soils by heavy metals is one of the major environmental issues today and may even compromise the estuaries throughout its length. Thus, a study was carried out in mangrove soils of the State of Ceará aiming their classification and characterization, beyond the determination of natural levels of metals in these soils and the consequent proposition of their QRV. For this, physical, chemical and mineralogical analyzes were realized, beyond the metals extraction by methods of semitotal digestion (EPA 3051A and aqua regia) and the determination of QRV was performed in accordance with the resolution 420/2009 of CONAMA. The results indicated that the semiarid climate preponderant in this region explains the behavior of the main attributes of these soils (ex: EC, TOC, mineral composition). It was also found that the levels of metals in these soils are influenced by the intensity of anthropogenic interference in the coastal environments, given that mangrove soils of Ceará River estuary, inserted into urban context and subjected to environmental stresses, showed the highest enrichment factors of metals. On the other hand, it was observed that the distribution of these elements in this environment is also regulated by interactions between the metals themselves and with attributes as clay and Fe and Mn oxides. Furthermore, the aqua regia digestion was efficient in extracting metals in these soils, while EPA 3051A, indicated by CONAMA for soil quality assessments, underestimated the available levels of metals in the analyzed soils. Given the above, the natural levels of metals determined in this study can serve as a basis for defining QRV for mangrove soils of the State of Ceará, assisting the environmental agency in the formulation of a specific legislation for monitoring mangrove areas in the State, thus setting a new perspective for the management of estuarine environments. / Nos dias de hoje, atividades relacionadas à urbanização e à industrialização têm contribuído para o aumento das concentrações de metais pesados nos diversos tipos de solo. Tais elementos apresentam relevante toxicidade e podem se acumular no ambiente, configurando sério risco à saúde humana e dos ecossistemas em geral. Nesse cenário, percebe-se uma preocupação crescente dos países em adotar uma política ambiental eficiente e, dessa forma, a determinação da concentração natural (níveis de background) de metais nos solos e o estabelecimento de valores de referência de qualidade (VRQs) já são realidade em alguns países, inclusive no Brasil. Entretanto, percebe-se a escassez de estudos dessa natureza que contemplem os solos sob florestas de mangue no país, onde tais áreas são bastante expressivas e desempenham importantes funções e serviços no ambiente. Nesse contexto, a contaminação dos solos de mangue por metais pesados é uma das grandes questões ambientais da atualidade, podendo, inclusive, comprometer os estuários em toda a sua extensão. Assim, foi realizado um estudo em solos de mangue do Estado do Ceará visando a classificação e caracterização dos mesmos, além da determinação dos teores naturais de metais e a consequente proposição de seus VRQs. Para isso, foram realizadas análises físicas, químicas e mineralógicas, extração dos metais por métodos de digestão semitotal (EPA 3051A e água régia) e a determinação dos VRQs foi realizada de acordo com o disposto na resolução n° 420/2009 do CONAMA. Os resultados obtidos indicaram que o clima predominantemente semiárido da região explica o comportamento dos principais atributos desses solos (ex: CE, COT, constituição mineralógica). Verificou-se ainda que os teores de metais nos solos em questão são influenciados pela intensidade da interferência antropogênica nos ambientes costeiros, tendo em vista que os solos de mangue do estuário do rio Ceará, inserido em contexto urbano e submetido a diversos tipos de tensões ambientais, apresentaram os maiores fatores de enriquecimento de metais. Por outro lado, observou-se que a distribuição de tais elementos nesses solos é também regida por interações entre os próprios metais e dos mesmos com atributos como a fração argila e os óxidos de Fe e Mn. Além disso, a digestão por água régia mostrou-se eficiente na extração de metais nesses solos, enquanto o EPA 3051A, indicado pelo CONAMA para avaliações de qualidade dos solos, subestimou os teores dos metais disponíveis nos mesmos. Diante do exposto, os teores naturais dos metais determinados no presente estudo podem servir de base para a definição de VRQs para os solos de mangue do Estado do Ceará, auxiliando o órgão ambiental responsável na formulação de uma legislação específica para o monitoramento das áreas de manguezal do Estado, configurando, portanto, uma nova perspectiva para a gestão dos ambientes estuarinos.