Seagrass and submerged aquatic vegetation (VAS) habitats off the Coast of Brazil: state of knowledge, conservation and main threats

Seagrass meadows are among the most threatened ecosystems on earth, raising concerns about the equilibrium of coastal ecosystems and the sustainability of local fisheries. The present review evaluated the current status of the research on seagrasses and submerged aquatic vegetation (SAV) habitats off the coast of Brazil in terms of plant responses to environmental conditions, changes in distribution and abundance, and the possible role of climate change and variability. Despite an increase in the number of studies, the communication of the results is still relatively limited and is mainly addressed to a national or regional public; thus, South American seagrasses are rarely included or cited in global reviews and models. The scarcity of large-scale and long-term studies allowing the detection of changes in the structure, abundance and composition of seagrass habitats and associated species still hinders the investigation of such communities with respect to the potential effects of climate change. Seagrass meadows and SAV occur all along the Brazilian coast, with species distribution and abundance being strongly influenced by regional oceanography, coastal water masses, river runoff and coastal geomorphology. Based on these geomorphological, hydrological and ecological features, we characterised the distribution of seagrass habitats and abundances within the major coastal compartments. The current conservation status of Brazilian seagrasses and SAV is critical. The unsustainable exploitation and occupation of coastal areas and the multifold anthropogenic footprints left during the last 100 years led to the loss and degradation of shoreline habitats potentially suitable for seagrass occupation. Knowledge of the prevailing patterns and processes governing seagrass structure and functioning along the Brazilian coast is necessary for the global discussion on climate change. Our review is a first and much-needed step toward a more integrated and inclusive approach to understanding the diversity of coastal plant formations along the Southwestern Atlantic coast as well as a regional alert the projected or predicted effects of global changes on the goods and services provided by regional seagrasses and SAV

Species Richness and Ecological Diversity of Myxomycetes and Myxomycete-Like Organisms in the Tropical Forests of Brazil

Tropical rain forests cover less than two percent of Earth\u27s surface, yet they sustain the greatest diversity of living organisms on the planet. Tropical rain forests cover nearly 73% of the Brazilian territory and besides harboring some of the most biodiverse ecosystems on the planet, this vast area also houses about 83% of the Brazilian population. Approximately 175 million people live in urban and rural areas with fragments of coverage of these biomes which contributes to the loss of biodiversity that rapidly increases over the years. Furthermore, the majority of the taxonomic and ecological efforts to describe and protect the Brazilian tropical biodiversity are usually focused on macroorganisms while the knowledge regarding the heterogeneity of microorganism species that compose the Brazilian microbiota increases slowly. Therefore, urgent efforts should be directed to the carrying out of inventories and studies on the species that make up the Brazilian microbiota, their biogeographical patterns, and their interactions with the environment in which they occupy. Aiming to contribute to the knowledge of the distribution and diversity of microorganism in the Neotropics, this dissertation includes (1) an overview of the biogeographical patterns of microorganisms; (2) a bibliographic revision of the myxomycetes species found in Brazil distributed among the different vegetation physiognomies throughout the country; (3) species listing and molecular identification of myxobacteria species; (4) the taxonomic and ecological studies of species of ceratiomyxomycetes and myxomycetes; (5) the taxonomic composition of dictyostelid cellular slime molds; and (6) species of protosteloid amoebae and related organisms present in tropical and subtropical moist broadleaf forests of Brazil

Variação temporal da comunidade fitoplanctônica em curtos intervalos amostrais no reservatório de Mundaú, Nordeste brasileiro

The aim of this study was to determine how abiotic factors drive the phytoplankton community in a water supply reservoir within short sampling intervals. Samples were collected at the subsurface (0.1 m) and bottom of limnetic (8 m) and littoral (2 m) zones in both the dry and rainy seasons. The following abiotic variables were analyzed: water temperature, dissolved oxygen, electrical conductivity, total dissolved solids, turbidity, pH, total nitrogen, nitrite, nitrate, total phosphorus, total dissolved phosphorus and orthophosphate. Phytoplankton biomass was determined from biovolume values. The role abiotic variables play in the dynamics of phytoplankton species was determined by means of Canonical Correspondence Analysis. Algae biomass ranged from 1.17×10(4) to 9.21×10(4) µg.L-1; cyanobacteria had biomass values ranging from 1.07×10(4) to 8.21×10(4) µg.L-1. High availability of phosphorous, nitrogen limitation, alkaline pH and thermal stability all favored cyanobacteria blooms, particularly during the dry season. Temperature, pH, total phosphorous and turbidity were key factors in characterizing the phytoplankton community between sampling times and stations. Of the species studied, Cylindrospermopsis raciborskii populations were dominant in the phytoplankton in both the dry and rainy seasons. We conclude that the phytoplankton was strongly influenced by abiotic variables, particularly in relation to seasonal distribution patterns.O objetivo deste estudo foi detectar a influência dos fatores abióticos sobre a comunidade fitoplanctônica em um reservatório de abastecimento, em curtos intervalos amostrais. As amostras foram coletadas na subsuperfície (0,1 m) e fundo das regiões pelágica (8 m) e litorânea (2 m), durante dois períodos sazonais, estações seca e chuvosa. As variáveis abióticas analisadas foram: temperatura da água, oxigênio dissolvido, condutividade elétrica, sólidos totais dissolvidos, turbidez, pH, nitrogênio total, nitrito, nitrato, fósforo total, fósforo total dissolvido e ortofosfato. A biomassa fitoplanctônica foi determinada a partir de valores de biovolume. A influência das variáveis abióticas na dinâmica das espécies fitoplanctônicas foi determinada através da Análise de Correspondência Canônica. A biomassa algal variou de 1,17×10(4) a 9,21×10(4) µg.L-1, sendo que as cianobactérias apresentaram valores de biomassa entre 1,07×10(4) e 8,21×10(4) µg.L-1. A mais alta disponibilidade de fósforo, limitação de nitrogênio, pH alcalino e estabilidade térmica favoreceram florações de cianobactérias, especialmente durante o período seco. As diferenças entre os horários e as estações amostrais na distribuição da comunidade fitoplanctônica foram determinadas pelos valores de temperatura, pH, fósforo total e turbidez. As associações fitoplanctônicas que mais se destacaram foram do grupo funcional Sn, formado por Cylindrospermopsis raciborskii, que predominou no sistema em ambos períodos sazonais. Concluiu-se que o fitoplâncton apresentou uma forte influência das variáveis abióticas especialmente no estabelecimento de padrões sazonais de distribuição.Conselho Nacional de Desenvolvimento Científico (CNPq

Population structure of the broad-snouted caiman (Caiman latirostris) in natural and man-made water bodies associated with a silvicultural landscape

The broad-snouted caiman (Caiman latirostris) is a South American crocodilian with a wide geographical distribution. Water bodies originally occupied by the species have suffered extreme anthropogenic pressure; however, the broad-snouted caiman has a high adaptive capacity to colonize man-made habitats such as decanting pounds and artificial reservoirs for agriculture or livestock. In this context, the present study aimed at identifying the population structure of the broad-snouted caiman in a silvicultural landscape in southeastern Brazil. Fifty-two caimans of various classes were captured with baited traps and steel cable snares at night. The estimated population size was 51 individuals. The population density was estimated to be 2.6 individuals/ha with a linear density of 11.3 individuals/km. The intermediate values of linear density estimates herein compared with other areas, suggesting that silvicultural landscapes can be relevant for broadsnouted caiman conservation. Therefore, the role of silvicultural landscapes in crocodilian conservation should be taken into consideration for environmental certification processes related to forestry in the Neotropics.Fil: Marques, Thiago Simon. Universidade de Sao Paulo; BrasilFil: Bassetti, Luís Antonio Bochetti. Universidade de Sao Paulo; BrasilFil: Lara, Neliton Ricardo Freitas. Universidade de Sao Paulo; BrasilFil: Millan, Cristian Honora. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Piña, Carlos Ignacio. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; ArgentinaFil: Verdade, Luciano Martins. Universidade de Sao Paulo; Brasi

Sensitivity of TDS-1 GNSS-R reflectivity to soil moisture: global and regional differences and impact of different spatial scales

The potential of Global Navigation Satellite Systems-Reflectometry (GNSS-R) techniques to estimate land surface parameters such as soil moisture (SM) is experimentally studied using 2014-2017 global data from the UK TechDemoSat-1 (TDS-1) mission. The approach is based on the analysis of the sensitivity to SM of different observables extracted from the Delay Doppler Maps (DDM) computed by the Space GNSS Receiver-Remote Sensing Instrument (SGR-ReSI) instrument using the L1 (1575.42 MHz) left-hand circularly-polarized (LHCP) reflected signals emitted by the Global Positioning System (GPS) navigation satellites. The sensitivity of different GNSS-R observables to SM and its dependence on the incidence angle is analyzed. It is found that the sensitivity of the calibrated GNSS-R reflectivity to surface soil moisture is ~ 0.09 dB/% up to 30° incidence angle, and it decreases with increasing incidence angles, although differences are found depending on the spatial scale used for the ground-truth, and the region. The sensitivity to subsurface soil moisture has been also analyzed using a network of subsurface probes and hydrological models, apparently showing some dependence, but so far results are not conclusive. © 2018 by the authors.Peer ReviewedPostprint (published version

Seasonal precipitation and anthropogenic pressure affect the water quality of reservoirs in the highland humid forest enclaves

Abstract Aim Humid forest enclaves are areas with privileged rainfall patterns compared to the surrounding regions, which favours their use for human settlement and agricultural activities, actions that promote severe transformations of the landscape and can contribute to the degradation of local water resources. From this perspective, given the great importance of water reservoirs for this region and the high demand for water, this study aimed to analyse the conservation status of water quality in reservoirs subjected to different anthropic disturbance in a humid forest enclave in the State of Paraíba, Brazil. Methods Sampling campaigns were carried out for one year in six reservoirs: Mazagão I, Mazagão II, Vaca Brava, Saulo Maia, Rio do Canto and Lagoa do Paó, to measure the physic-chemical variables of the water. Results The influence of annual rainfall patterns on the capacity of these ecosystems to respond to anthropic pressures, indicating the effects of seasonality in the Lagoa do Paó reservoir. For the Vaca Brava, the low accumulated water volumes turned out to be more critical for changes in water quality than the use and occupation of the margins of this reservoir. Furthermore, the Mazagão I and II reservoirs showed low electrical conductivity. The Saulo Maia reservoir exhibit clear waters with low phosphorus content and can be used as a reference for a preserved environment for a highland humid forest enclave. Conclusions The conservation of the reservoir environment in the highland humid forest enclave is not sufficient to guarantee the water quality, as it is concentrated an affected at a certain time of the year. These aquatic ecosystems are under great pressure and the lack of decisions based on technical criteria makes them vulnerable to eutrophication

Social Wasps (Hymenoptera: Vespidae: Polistinae) from Northeastern Brazil: State of the Art

For many years, research about social wasps in the Northeast was neglected due to its climatic and vegetative characteristics, insufficient incentive for training researchers to study these animals and perpetuation of low diversity of these groups in arid environments proposed by Ducke. This study carried out a bibliographic survey of research about social wasps in a 40 years period from January/1979 to December/2019, to determine the overall reality of biodiversity and richness knowledge for social wasps species. One hundred and twenty-four (124) social wasp species have been registered in the Northeast Region, distributed among 20 genera. Epiponini stands out with 84 species, followed by Mischocyttarini (24) and Polistini (16). Sergipe is the only state with no studies and records of species thus far. Such results show the importance of continuing taxonomic studies of these insects to expand their geographic distribution and to determine areas for environmental preservation in the Northeastern biomes, i.e., the Caatinga sensu lato, Cerrado and Amazon rainforest and their transition zones, as they have been insufficiently studied and present high potential for new discoveries. We suggest Alagoas, Ceará, Pernambuco and, especially Sergipe as priority areas since there is a lacking data in these states. Finally, we recommend continuing research on species reports in states like Bahia, using the map created herein to choose future study areas

Drought impacts assessment in Brazil - a remote sensing approach

Climate extremes are becoming more frequent in Brazil; studies project an increase in drought occurrences in many regions of the country. In the south, drought events lead to crop yield losses affecting the value chain and, therefore, the local economy. In the northeast, extended periods of drought lead to potential land degradation, affecting the livelihood and hindering local development. In the southern Amazon, an area that experienced intense land use change (LUC) in the last, the impacts are even more complex, ranging from crop yield loss and forest resilience loss, affecting ecosystem health and putting a threat on the native population traditional way of living. In the studies here we analyzed the drought impacts in these regions during the 2000s, which vary in nature and outcomes. We addressed some of the key problems in each of the three regions: i) for the southern agriculture, we tackled the problem of predicting soybean yield based on within-season remote sensing (RS) data, ii) in the northeast we mapped areas presenting trends of land degradation in the wake of an extended drought and, iii) in southern Amazon, we characterized a complex degradation cycle encompassing LUC, fire occurrence, forest resilience loss, carbon balance, and the interconnectedness of these factors impacting the local climate. Advisor: Brian D. Wardlo

ASSESSMENT OF HYDROLOGICAL MASS LOSSES IN THE NORTHEAST ATLANTIC EASTERN HYDROGRAPHIC REGION, BRAZIL

Freshwater monitoring globally is fundamental to support decision-making. However, long-term hydrological data for some regions are lacking due to limited of observational networks. Remote sensing products come to aggregate the in situ observations and overcome obstacles about data availability. This study assesses the hydrological mass losses in the Northeast Atlantic Eastern Hydrographic Region (NAEHR) in Brazil through temporal data sources. GRACE RL06 Mascon solutions, reservoirs volume, vegetation index and rainfall stations are used. The results confirm the cohesion between the TWS variations with water volume and NDVI, obtaining a strong correlation of 0.78 and 0.77 respectively. The Standardized Precipitation Index scales (12, 24 and 36 months) showed a moderate and strong correlation with the TWS of 0.57, 0.73 and 0.72 respectively and identified the last regional severe drought from 2012 to 2017. The NEAHR is located almost entirely in the Brazilian semiarid region, comprises about 24 million inhabitants, it is high vulnerable to drought, thus justifying the importance of monitoring its water resources availability