Spatial variation of stable hydrogen and oxygen isotopes in tap water in Brazil.

Compared to global models, regional water isoscapes have increased spatial coverage sampling to better represent the territory patterns and decrease the uncertainty of isoscapes. Here, we present the first tap water isoscapes for Brazil. We collected 575 tap water samples and analyzed for δO and δH using a pyrolysis technique coupled to isotope ratio mass spectrometer for isotope ratio determination.

Urbanization-induced simplification of isotopic space in birds from a big Neotropical city.

Among the many changes associated with the urbanization process, changes in resource availability can directly impact local wildlife populations. Urban areas suppress native vegetation and convert natural environments into impervious surfaces, modifying the composition and quantity of available food resources. Understanding the food requirements of species is crucial, mainly because it is one of the main elements that characterize their ecological niche and structure local communities.

Differentiating wild from captive animals: an isotopic approach.

Background: Wildlife farming can be an important but complex tool for conservation. To achieve conservation benefits, wildlife farming should meet a variety of criteria, including traceability conditions to identify the animals' origin. The traditional techniques for discriminating between wild and captive animals may be insufficient to prevent doubts or misdeclaration, especially when labels are not expected or mandatory.

Soil δN spatial distribution is primarily shaped by climatic patterns in the semiarid Caatinga, Northeast Brazil.

Soil nitrogen isotopic composition (δN) is an invaluable tool as it integrates nitrogen (N) transformations in soils. In addition to serving as a baseline to understand the N cycle, spatial representations of δN across landscapes (or isoscapes) is a multi-purpose tool useful to investigate, for example, plant-microbe interactions, animal migration and forensics. We investigate the climatic and edaphic controls of δN utilising data from 29 geographical locations sampled across the semiarid Brazilian Caatinga biome.

Sources of intraspecific variation in the isotopic niche of a semi-aquatic predator in a human-modified landscape.

Intraspecific variation modulates patterns of resource use by species, potentially affecting the structure and stability of food webs. In human-modified landscapes, habitat disturbance modifies trophic interactions and intraspecific niche variation, impacting population persistence. Here, we investigated the relationship of sex, ontogeny, and habitat factors with the trophic niche of in an agricultural landscape.

Agricultural input modifies trophic niche and basal energy source of a top predator across human-modified landscapes.

Land-use conversion and resulting habitat fragmentation can affect the source(s) of primary productivity that fuels food webs and alter their structure in ways that leads to biodiversity loss. We investigated the effects of landscape modification on food webs in the Araguaia River floodplain in central Brazil using the top predator, and indicator species (Crocodilia, Alligatoridae). We measured carbon ( ) and nitrogen ( ) isotope values of three tissues with different isotopic incorporation rates to evaluate spatial and temporal changes in caiman isotopic niche width with hierarchical Bayesian models that accounted for habitat use, intraspecific trait variation (sex and body size), and landscape attributes (composition and configuration).

A feather hydrogen (δ2H) isoscape for Brazil.

Spatial patterns of stable isotopes in animal tissues or "isoscapes" can be used to investigate animal origins in a range of ecological and forensic investigations. Here, we developed a feather hydrogen isotope (δ2Hf) isoscape for Brazil based on 192 samples of feathers from the family Thraupidae from scientific collections. Raw values of δ2Hf ranged from -107.

Potentially toxic elements and rare earth elements in sandy soils from the Brazilian Cerrado.

This study aims to determine the concentration of potentially toxic elements (PTEs) and rare earth elements (REEs) in Brazilian sandy soils under the Cerrado at the Parnaíba-São Francisco Basin transition. We also explored the geochemical correlation between these elements and pH, cation exchange capacity (CEC), total organic carbon (TOC), sand, clay, oxides from secondary minerals, and chemical index of alteration for each basin. Mineralogical, physical, and chemical analyses were used to examine PTE and REE geochemistry in six sand soil profiles from the Brazilian Cerrado.

Plant invasion affects vegetation structure and sediment nitrogen stocks in subtropical mangroves.

Plant invasion can primarily affect the structure and functioning of terrestrial and aquatic ecosystems. Although there is evidence that plant invasion can modify organic matter dynamics in mangroves, it is uncertain whether and to which extent these changes can affect carbon (C) and nitrogen (N) dynamics in the sediment-plant system. Here, we measured: (i) the structure of native vegetation and C and N in the sediment-plant system in subtropical mangroves subjected to aquatic macrophytes invasion in southeastern Brazil.

Spatial distribution of soil δC in the central Brazilian savanna.

Stable carbon isotope ratios (δC) of soil record information regarding C and C plants at the landscape scale that can be used to document vegetation distribution patterns. The Central Brazilian savanna (locally called the Cerrado) has a substantial potential to develop studies of patterns of dynamics and distribution of soil δC, due to its environmental diversity. The purpose of this work was to develop a spatial model of soil δC (soil δC isoscape) to the Cerrado, based on multiple linear regression analysis, and compare the results with the existing model to obtain greater detail of the soil δC distribution.

Impacts of market economy access and livelihood conditions on agro-food transition in rural communities in three macro-regions of Brazil.

Urbanization has threatened rural communities' livelihoods worldwide, changing their agro-food systems from locally produced traditional items to industrialized foodstuffs. The main objective was to investigate the relationship between livelihood conditions and the agro-food transition process in rural communities of the Center-West, Northeast, and Amazon regions of Brazil. We hypothesized that traditional agroecosystems and local food habits changed with greater access to market economies.

Factors affecting the effectiveness of riparian buffers in retaining sediment: an isotopic approach.

Riparian forest width is a major driver of their capacity to retain sediments from agricultural fields. However, the relationship between forest width and ecosystem service provisioning may vary with local environmental conditions such as relief, soil, and vegetation types. In order to assess the effect of forest width, slope, hydraulic conductivity, and land cover (watershed scale) on the effectiveness of riparian buffers in retaining sediment from pastures cultivated with African C grasses, we used the natural abundance of carbon stable isotopes (δC) in the soil and stream organic sediments as indicators.

Biological nitrogen fixation across major biomes in Latin America: Patterns and global change effects.

Biological nitrogen fixation (BNF) supports terrestrial primary productivity and plays key roles in mediating human-induced changes in global nitrogen (N) and carbon cycling. However, there are still critical uncertainties in our understanding of the amount of BNF occurring across terrestrial ecosystems, and of how terrestrial BNF will respond to global change. We synthesized BNF data from Latin America, a region reported to sustain some of the highest BNF rates on Earth, but that is underrepresented in previous data syntheses.

Increased in carbon isotope ratios of Brazilian fingernails are correlated with increased in socioeconomic status.

High C in human tissues in Brazil indicate high consumption of C-based sources due to the consumption of highly processed food and animal protein. The significant positive correlation between the human developed index (HDI) developed by the United Nations Development Program, and fingernail C at the county level proved to be useful as a new proxy in tracking human nutrition. Regions with higher HDI are those with higher consumption of highly processed food.

Consequences of removal of exotic species (eucalyptus) on carbon and nitrogen cycles in the soil-plant system in a secondary tropical Atlantic forest in Brazil with a dual-isotope approach.

The impact of exotic species on heterogeneous native tropical forest requires the understanding on which temporal and spatial scales these processes take place. Functional tracers such as carbon (δC) and nitrogen (δN) isotopic composition in the soil-plant system might help track the alterations induced by the exotic species. Thus, we assess the effects from the removal of the exotic species eucalyptus () in an Atlantic forest Reserve, and eucalyptus removal on the alteration of the nutrient dynamics (carbon and nitrogen).

Mapping carbon and nitrogen isotopic composition of fingernails to demonstrate a rural-urban nutrition transition in the Center-West, Northeast, and Amazon regions of Brazil.

Objective: The main objective of this study is to investigate diet patterns among rural and urban populations of the Center-West, Northeast, and Amazon regions of Brazil through the carbon and nitrogen isotopic composition of fingernails, recognizing that the extent of market integration is a key driver of food consumption.

Materials And Methods: In the Center-West, Northeast, and Amazon regions of Brazil, fingernails were sampled in clusters encompassing a major city, town, and rural village. A total of 2,133 fingernails were analyzed.

Carbon and Nitrogen Isotope Ratios of Food and Beverage in Brazil.

Several previous studies on targeted food items using carbon and nitrogen stable isotope ratios in Brazil have revealed that many of the items investigated are adulterated; mislabeled or even fraud. Here, we present the first Brazilian isotopic baseline assessment that can be used not only in future forensic cases involving food authenticity, but also in human forensic anthropology studies. The δC and δN were determined in 1245 food items and 374 beverages; most of them made in Brazil.

Conditional Cash Transfers in the Amazon: From the Nutrition Transition to Complex Dietary Behavior Change.

Nutrition transition theory describes a progressive substitution of local staples for industrialized processed foods in local diets, a process documented diversely across world regions, and increasingly observed in rural areas of the global south. Here we examine the role of conditional cash transfer programs, in particular the emblematic Brazilian (BFP), in driving nutritional transition in rural areas of the Amazon. Based on ethnographic research with both participating and nonparticipating women in the Amanã Sustainable Development Reserve (SDR), our analysis integrates Food Frequency Questionnaires (FFQ), seasonal 24-hour food intake recalls, and stable isotope ratios in fingernails to examine dietary behavioral change.

Nitrogen input by bamboos in neotropical forest: a new perspective.

Background: Nitrogen (N) is an important macronutrient that controls the productivity of ecosystems and biological nitrogen fixation (BNF) is a major source of N in terrestrial systems, particularly tropical forests. Bamboo dominates theses forests, but our knowledge regarding the role of bamboo in ecosystem functioning remains in its infancy. We investigated the importance of a native bamboo species to the N cycle of a Neotropical forest.

Food Insecurity in Urban and Rural Areas in Central Brazil: Transition from Locally Produced Foods to Processed Items.

Aiming to investigate the effect of diet and food consumption with regard to health, environment, and economy in light of nutrition ecology, we studied the dimensions of nutrition and food security in urban and rural settings in the region of Chapada dos Veadeiros, Central Brazil. We tracked diet and food consumption through carbon and nitrogen stable isotope ratios in fingernails of these inhabitants together with food intake data as a proxy for their diet patterns. We estimated household food insecurity by using the Brazilian Food Insecurity Scale.

Land Use Influences Niche Size and the Assimilation of Resources by Benthic Macroinvertebrates in Tropical Headwater Streams.

It is well recognized that assemblage structure of stream macroinvertebrates changes with alterations in catchment or local land use. Our objective was to understand how the trophic ecology of benthic macroinvertebrate assemblages responds to land use changes in tropical streams. We used the isotope methodology to assess how energy flow and trophic relations among macroinvertebrates were affected in environments affected by different land uses (natural cover, pasture, sugar cane plantation).