Coloured dissolved organic matter (CDOM) is the most abundant dissolved organic matter (DOM) in many natural waters and can affect the water quality, such as the light penetration and the thermal properties of water system. So the objective of this letter was to estimate the CDOM absorption coefficient at 440 nm, a CDOM (440), in Barra Bonita Reservoir (São Paulo State, Brazil) using operational land imager (OLI)/Landsat-8 images. For this two field campaigns were conducted in May and October 2014. During the field campaigns remote sensing reflectance (R rs) were measured using a TriOS hyperspectral radiometer. Water samples were collected and analysed to obtain the a CDOM (440). To predict the a CDOM (440) from R rs at two key wavelengths (650 and 480 nm) were regressed against laboratory-derived a CDOM (440) values. The validation using in situ data of a CDOM (440) algorithm indicated a goodness of fit, R 2 = 0.70, with a root mean square error (RMSE) of 10.65%. The developed algorithm was applied to the OLI/Lansat-8 images. Distribution maps were created with OLI/Landsat-8 images based on the adjusted algorithm.

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Global urban expansion has multiple impacts on biodiversity and ecosystem functioning. Still, urban centres may play an important role in the conservation of reptiles, an undersampled, megadiverse and unevenly distributed group especially vulnerable to anthropogenic impacts. However, major gaps in research on the urban ecology of reptiles and species responses to urbanisation persist, which may limit our capacity to guide suitable conservation policies. We conducted a global systematic literature review to evaluate biogeographic, taxonomic and ecological research biases in the urban ecology of reptiles and ultimately to detect major gaps and steer future sampling efforts. Our database comprised 278 articles dealing with biological responses to urbanisation of 493 species across 45 countries, comprising 658 cases between a given species and specific biological response. Research on the urban ecology of reptiles was geographically and taxonomically biased. Developed countries within temperate regions were better sampled, whereas developing tropical and megadiverse countries were mostly undersampled or neglected. Among reptile orders, Testudines and Crocodylia were proportionally more studied than Squamata. Across lower groups within Squamata, lizards were present in most studies and were the biological model most commonly used. Studies evaluating biological responses associated with landscape-level processes, behaviour and/or population dynamics were prevalent, whereas conservation, human-reptile conflicts and wildlife management were the least considered topics. Our results show that research on urban ecology of reptiles is unevenly distributed across regions and lineages. Overcoming these major gaps is an important step towards the improvement of the conservation of reptiles worldwide under the upcoming biodiversity loss scenario. Beyond spreading sampling efforts across undersampled countries, taxa and research topics to meet conservation objectives, we recommend more multidisciplinary approaches to evaluate and compare the actual performance of reptiles in urban environments and to achieve the equilibrium between human well-being and species conservation.

While taxonomic and biogeographical biases are often acknowledged, those for certain biological responses and species traits are routinely overlooked, generating major gaps in knowledge and conservation of biodiversity. Biases in research on birdsan over-sampled, diverse vertebrate classmay be readily detectable, and wetlands are important species-rich ecosystems in which to identify biases and research gaps for birds. The Pantanal, one of the world's largest wetlands, is globally relevant for bird conservation. In this wetland, we determined spatial, temporal, taxonomic and biological response-related biases in ornithological studies to guide future research in this ecosystem and, ultimately, in major global wetlands. Avian research was geographically biased, with 61 studies conducted in the Brazilian Pantanal and only one in Bolivia. Most studies were concentrated near urban centres, with poorly explored areas in the central Pantanal. Research was also over-represented during the dry season when field conditions are more favourable, but such temporal bias may hamper migration studies. Considering their richness, some families were studied disproportionately more (e.g. Jacanidae) or less (e.g. Tyrannidae). Some species (e.g. Wood Stork Mycteria americana and Yellow-billed Cardinal Paroaria capitata) were included in > 25% of studies, whereas a relatively low number of threatened bird species were studied. Behaviour was the most studied response, followed by abundance and reproduction, which were considered for > 65% of species studied. We conclude that further research needs to be focused on unexplored areas and periods, less detectable species, and ecological processes (e.g. interspecific interactions). Additionally, our results can provide useful information to better address future work and bird conservation actions in other large wetlands. For example, major gaps detected here constitute a primary roadmap to guide research in under-sampled regions, such as the Canadian peatlands and Tonlé Sap Lake. Specifically, more studies on waterbirds in highly diverse wetlands from low-income countries (e.g. Okavango and Sundarban Delta) may help to disentangle the essential functional role provided for these species and to prioritize conservation actions in regions with limited research capacity.

Habitat loss and fragmentation are the primary causes of global population decline of amphibians and reptiles. In Brazil, that hosts an extraordinary herpetofaunal richness, amphibians and reptiles are clearly undersampled among vertebrate groups in fragmentation research. This bias may underestimate the effects of fragmentation on herpetofauna in this megadiverse country. Here, we conducted an exhaustive literature review to evaluate the effects and patterns of fragmentation on amphibians and reptiles in Brazil. We analyzed 55 papers between 1994 and 2020, comprising 350 cases of the effect (positive, negative, or neutral) of a given fragmentation metric on a particular biological response. Forest biomes (Amazon and Atlantic Forest) were largely overrepresented in relation to non-forest biomes, comprising 82% of studies. We also found a disproportional prevalence of fragmentation articles on amphibians (75%). Among lower taxonomic groups, Anura and Testudines were significantly overrepresented, whereas Caudata and Crocodylia were neglected. Fragment size reduction, habitat degradation, habitat loss, and matrix contrast were the most studied metrics (70% of studies), while single-species abundance was the most considered response (59%). The effects of fragmentation were not statistically different between amphibians and reptiles. In general, the impacts were predominantly negative or neutral, while positive effects were infrequent or even non-existent. Our findings suggest that amphibians and reptiles respond similarly and may not be as vulnerable to fragmentation. We call future research to consider non-forest biomes and less-studied taxonomic groups (e.g., Squamata) to fully understand the effects of fragmentation on the megadiverse Brazilian herpetofauna and to take well-informed conservation actions.