Brazilian Pantanal Wetland Research Articles

Disentangling the path of pollinator attraction in temporarily colored flowers

Plants may use different strategies to attract pollinators in long distance (e.g. floral display) and in short distance (e.g. ratio between differentially colored flowers) scales. The Verbenaceae Lantana canescens Kunth is a wide spread species in open sites of the Brazilian Pantanal wetland. Individuals of this generalist species can produce a variable number of open inflorescences with yellow and white flowers that are organized in whorls. In this study we tested the hypothesis that increased floral display (long distance attraction) and the ratio between yellow and white flowers (short distance attraction) enhances the number of pollinator species and individuals. We observed flower visitors and calculated floral parameters in 38 plots of 1 m2 each, that contained a varying number of flowering L. canescens individuals. Non-metric multidimensional scaling and Bray-Curtis distances were used to account for flower visitor composition and the relative visitation rate, respectively. We used a structural equation model to test the power of each predictor variable on the visitation rate and a covariance analysis to disentangle the effect of each independent variable on the frequency of plant-pollinator interactions. We found that the number of flower visitors and the visitation rate increased with increasing number of inflorescences. Disentangling long and short distance attraction indicated that the number of inflorescences (per plot) and the number of yellow flowers (yellowing effect) contributed most to flower visitation at long and short distance, respectively.

Landscape changes in avulsive river systems: Case study of Taquari River on Brazilian Pantanal wetlands

The Pantanal is an important active sedimentary basin in central South America where highly diverse flora and fauna are sustained by seasonal floods. Intense land use in the catchment areas enhanced sediment load and destabilized avulsive river systems in the plains. A well-known avulsion in the Taquari River during the 1980–90s, called “Zé da Costa”, has shifted the river mouth and drastically changed the nearby landscapes, making them difficult to map because of the hard access and the large variations in spectral and spatial attributes of raster data like Landsat images. Therefore, we developed a useful method to map and explore landscape changes in “Zé da Costa” avulsion that combines geotagged field pictures, randomly selected high-resolution orbital truths, normalized difference vegetation index, digital elevation models, linear spectral mixture models and Landsat historical imagery in pixel-based and object-oriented supervised classifications. We found that bands in green, red, and near-infrared spectra provide better mapping results with object-oriented algorithms for deriving and studying temporal dry/wet ratio dynamics. The temporal analyses of the dry/wet ratio showed that avulsions in the Taquari River have the potential to change permanently the “Zé da Costa” area into a dry landscape, making it susceptible for land use (deforestation and fire), except areas seasonally inundated by the floods of the Paraguay River. Overall, our method might be also useful for long-term studies of land use and climate change in avulsive rivers in wetlands around the world.

Changing fluvial styles and backwater flooding along the Upper Paraguay River plains in the Brazilian Pantanal wetland

The channel-floodplain relationship is used to understand flooding dynamics in the Pantanal wetland. To understand how different fluvial styles along the Upper Paraguay River (UPR) control the hydrology of the Pantanal wetland, we used a database including 11 gauge stations from the Brazilian National Agency of Waters, Landsat series satellite data, GeoCover images circa 1990 and 2000, the SRTM 90m digital elevation model (DEM) and 34 acoustic Doppler current profiler (ADCP) sections. We defined eight very distinct fluvial zones in the UPR within the Pantanal based on the channel-floodplain morphology, channel pattern, hydrologic function, and channel slope. Three zones are narrowing plains (Amolar, Urucum and Fecho dos Morros) constrained by geological features on the western border of the Pantanal sedimentary basin, which act as bottlenecks for flood runoff and produce backwater effects that delay flood wave transmission. In each of these narrow zones, the flood wave is delayed by flow velocity reduction, generating huge water bodies upstream that store flood water and affect the duration and amplitude of floods. The existence of three bottlenecks and the occurrence of a backwater effect constrain flood waves along the river, conditioning the hydrological regime of the entire wetland and resulting in unusual rating curves at some gauge stations along the UPR. This peculiar hydrological regime is responsible for the functioning of the wetland, including the undesirable “dequada” phenomena (natural fish mortality events). The backwater effect is enhanced by the existence of large flood basins upstream of the bottlenecks, where waters can be temporarily retained for periods of months, delaying the surface runoff and prolonging the flood season, which contributes to the maintenance of the wetland and its rich ecosystem.

Novel Viruses in Mosquitoes from Brazilian Pantanal.

Viruses are ubiquitous and diverse microorganisms arising as a result of interactions within their vertebrate and invertebrate hosts. Here we report the presence of different viruses in the salivary glands of 1657 mosquitoes classified over 28 culicinae species from the North region of the Brazilian Pantanal wetland through metagenomics, viral isolation, and RT-PCR. In total, 12 viruses were found, eight putative novel viruses with relatively low similarity with pre-existing species of viruses within their families, named Pirizal iflavirus, Furrundu phlebovirus, Pixé phlebovirus, Guampa vesiculovirus, Chacororé flavivirus, Rasqueado orbivirus, Uru chuvirus, and Bororo circovirus. We also found the already described Lobeira dielmorhabdovirus, Sabethes flavivirus, Araticum partitivirus, and Murici totivirus. Therefore, these findings underscore the vast diversity of culicinae and novel viruses yet to be explored in Pantanal, the largest wetland on the planet.

Isoetes dubsii and Isoetes santacruzensis, two new species from lowland areas in South America.

Isoetes dubsiisp. nov. and I. santacruzensissp. nov., two new species from lowland areas in South America, are described, illustrated and compared to similar species. Isoetes dubsii can be distinguished from other species of the Brazilian Pantanal wetlands by a set of characters including leaves that are long, flexuous and trigonal in transverse section, tri-lobate stems, rudimentary velum, pustulate megaspores of 310‒390 µm diameter and laesurae of the megaspore at least four times wider than high. Isoetes santacruzensis has flexuous, filiform leaves, 0.4–0.8 mm wide at mid length and reaching up to 15 cm long, black or reddish-black sporangia, sclerified phyllopodia and sparsely verrucate megaspores of 320‒390 µm in diameter. We also include a key for species from the Brazilian Pantanal wetlands and Bolivia and spore images for all species that are discussed. Isoetes dubsii and I. santacruzensis are only known from their type localities and they may deserve special attention concerning their conservation status. However, based on our current knowledge on these species and according to IUCN Red List criteria, they are assessed here as data deficient (DD).

Variation in the prevalence and abundance of acanthocephalans in brown-nosed coatis Nasua nasua and crab-eating foxes Cerdocyon thous in the Brazilian Pantanal.

Host infection by parasites is influenced by an array of factors, including host and environmental features. We investigated the relationship between host sex, body size and age, as well as seasonality on infection patterns by acanthocephalan in coatis (Procyonidae: Nasua nasua) and in crab-eating foxes (Canidae: Cerdocyon thous ) from the Brazilian Pantanal wetlands. Between 2006 and 2009, we collected faecal samples from these hosts and analyzed for the presence of acanthocephalan eggs. Prevalence, abundance and intensity of eggs of acanthocephalans were calculated. Egg abundance was analyzed using generalized linear models (GLM) with a negative binomial distribution and models were compared by Akaike criteria to verify the effect of biotic and abiotic factors. Prevalence of acanthocephalans was higher in the wet season in both host species but did not differ between host sexes; however, adult crab-eating foxes showed higher prevalence of acanthocephalan eggs than juveniles. In contrast, prevalence of acanthocephalan eggs found in coatis was higher in coati juveniles than in adults. Host age, season and maximum temperature were the top predictors of abundance of acanthocephalan eggs in crab-eating foxes whereas season and host sex were predictors of egg abundance in coatis. The importance of seasonality for abundance of acanthocephalan was clear for both host species. The influence of host-related attributes, however, varied by host species, with host gender and host age being important factors associated with prevalence and parasite loads.

Chance, luck and a fortunate finding: a new species of watersnake ofthe genus Helicops Wagler, 1828 (Serpentes: Xenodontinae), from the Brazilian Pantanal wetlands.

We describe a new watersnake of the genus Helicops based on a single specimen found in the northern limit of the Brazilian Pantanal. Immediately after collection, the unique features of color pattern and head proportions prevented us to attribute this specimen to any other congener. Further comparisons revealed that the combination of entire nasal scales, a distinctively acuminate snout, high dorsal and supralabial counts, as well as a dorsal pattern with chain-like spot rows and a venter with vivid and peculiar orange markings confirmed that the specimen represented a new species. Molecular data supported our morphological conclusion recovering the new species deeply nested within Helicops terminals, sister to a clade composed by H. carinicaudus and H. nentur. Our discovery represents a rare instance of a snake species restricted to the Brazilian Pantanal, but we refrain from considering it a Pantanal endemic until further records allow more considerations on distributional patterns.

A New Species of Pachysentis Meyer, 1931 (Acanthocephala: Oligacanthorhynchidae) in the Brown-Nosed Coati Nasua nasua (Carnivora: Procyonidae) from Brazil, with Notes on the Genus and a Key to Species

IntroductionPachysentis comprises 10 species, which have been reported parasitizing mammals in Africa and the American continent. However, species of Pachysentis have not been described in brow-nosed coatis. Pachysentis lauroi n. sp. (Oligacanthorhynchidae: Acanthocephala) is described from the brown-nosed coati Nasua nasua (Linnaeus, 1766) Storr, 1780 (Procyonidae: Carnivora) in the Brazilian Pantanal wetlands of the Mato Grosso do Sul State, Brazil. MethodsSpecimens were studied using light and scanning electron microscopy. ResultThe new species is distinguished from other species of Pachysentis by the number of hooks in each longitudinal row (12 rows of 4 hooks, total of 48 hooks), presence of barbs on all hooks, and the organization of the cement glands. Notes on the genus Pachysentis [14] and a key to its species are provided. Critical comments on some species with a dubious diagnosis and questionable or missed key taxonomic characteristics are also reviewed. We also discuss the zoogeography of the members of the genus.

Influential factors on gray brocket deer (Mazama gouazoubira) activity and movement in the Pantanal, Brazil

One of the major challenges in studies of activity and movement ecology is discovering how and why animals behave differently in certain environments. The gray brocket deer (Mazama gouazoubira) is widely distributed in the Neotropic region. In the Brazilian Pantanal wetland, gray brocket deer inhabit a unique landscape with varying ecotypes arranged in a mosaic, where seasonal flooding alters resource availability for the deer. Documenting animal activity and movement can be the key to understanding how a species interacts with its dynamic environment. We used data from accelerometers and characteristics of movement on six GPS-monitored gray brocket deer in the Pantanal wetland to investigate how habitat type, periods of the day, and cycles of flooding and drought affect activity, movement behavior, and displacement. Deer exhibited the lowest activity and encamped movement in closed habitat during diurnal and nocturnal periods, suggesting resting and foraging behaviors. The highest activity and exploratory movement occurred in open habitats, and potentially was related to deer searching for locations with greater resource availability. Individuals were displaced the most during floods, which was a response to access feeding sites that were free of water. Our results not only represent an unprecedented and refined view of the activity and movement behavior of brocket deer, but they also stress the importance of preserving multiple habitat types for species that express variable foraging strategies in heterogeneous landscapes.

Assessment of equine piroplasmids in the Nhecolândia sub-region of Brazilian Pantanal wetland using serological, parasitological, molecular, and hematological approaches

Brazilian Pantanal is the world´s largest wetland ecosystem, where cattle’s ranching is the most important economic activity. The objective of this study was to compile some epidemiological features on equine piroplasmids from the Nhecolândia sub-region of Pantanal wetland through the evaluation of the patterns of T. equi and B. caballi infections in different groups of horses; identification of the tick species that infest horses; and to study phylogenetic relationships among Theileria equi 18S rRNA gene sequences. During October 2015, blood and serum samples were collected from 170 horses in four different categories. Ticks, after identification, had their hemolymph and eggs examined for the presence of piroplasmid sporokinets. Also we searched parasites in the peripheral blood smears of the investigated horses. The number of red blood cells (RBCs) and the packed cell volume (PCV) ​​were determined to test for anemia in the infected animals, and exposure to B. caballi and T. equi was evaluated by enzyme-linked immunosorbent assay. “Catch all primers” based on 18S rRNA gene were used in polymerase chain reactions (PCR) to detect equine piroplasmids, followed by three nested PCRs for the phylogenetic analysis. The serological results showed that 61.8% and 52.9% of the horses sampled were exposed to T. equi and B. caballi, respectively. Piroplasmid DNA was detected in 43.5% of the horses analyzed. Our sequencing revealed 98–100% identity with some sequences previously published in GenBank for T. equi, and microheterogeneity among others. We found that 51.2% of the animals sampled were infested with Dermacentor nitens, Amblyomma sculptum, and Rhipicephalus (Boophilus) microplus, singly or co-infested. Since positive and negative animals presented similar RBC and PCV values, and no sporokinets were found on blood smears, hemolymph and eggs of the ticks collected, we suggest that infected equines can act as asymptomatic carriers for piroplasmosis in the studied region. Our results together showed the enzootic characteristic of equine piroplasmids in Pantanal region highlighting the importance of using different methods for detection these parasites. Moreover, breeding mares and foals should be monitored since they displayed the greatest occurrences for molecular test (59.0% and 86.1% respectively) and tick infestations (87.2% and 63.9% respectively).

Dung beetle diversity and functions suggest no major impacts of cattle grazing in the Brazilian Pantanal wetlands

1. Dung beetles perform relevant ecological functions in pastures, such as dung removal and parasite control. Livestock farming is the main economic activity in the Brazilian Pantanal. However, the impact of cattle grazing on the Pantanal's native dung beetle community, and functions performed by them, is still unknown.2. This study evaluated the effects of cattle activity on dung beetle community attributes (richness, abundance, biomass, composition, and functional group) as well as their ecological functions (dung removal and soil bioturbation) in the Pantanal. In January/February 2016, dung beetles were sampled and their ecological functions measured in 16 sites of native grasslands in Aquidauana, Mato Grosso do Sul, Brazil, 10 areas regularly grazed by cattle and six control ungrazed areas (> 20 years of abandonment).3. In all, 1169 individuals from 30 species of dung beetles were collected. Although abundance, species richness, and biomass did not differ between grasslands with and without cattle activity, species composition and functional groups differed among systems. Large roller beetles were absent from non‐cattle grasslands, and the abundance, richness, and biomass of medium roller beetles was higher in those systems.4. Despite causing changes in species/functional group composition, the results of this study show that a density compensation of functional groups in cattle‐grazed natural grasslands seems to have conserved the ecological functions (dung removal and soil bioturbation), with no significant differences between systems.5. Therefore, these results provide evidence that cattle breeding in natural grasslands of the Brazilian Pantanal can integrate livestock production with the conservation of the dung beetle community and its ecological functions.

Considerations for monitoring population trends of colonial waterbirds using the effective number of breeders and census estimates.

Detecting trends in population size fluctuations is a major focus in ecology, evolution, and conservation biology. Populations of colonial waterbirds have been monitored using demographic approaches to determine annual census size (N a). We propose the addition of genetic estimates of the effective number of breeders (N b) as indirect measures of the risk of loss of genetic diversity to improve the evaluation of demographics and increase the accuracy of trend estimates in breeding colonies. Here, we investigated which methods of the estimation of N b are more precise under conditions of moderate genetic diversity, limited sample sizes and few microsatellite loci, as often occurs with natural populations. We used the wood stork as a model species and we offered a workflow that researchers can follow for monitoring bird breeding colonies. Our approach started with simulations using five estimators of N b and the theoretical results were validated with empirical data collected from breeding colonies settled in the Brazilian Pantanal wetland. In parallel, we estimated census size using a corrected method based on counting active nests. Both in simulations and in natural populations, the approximate Bayesian computation (ABC) and sibship assignment (SA) methods yielded more precise estimates than the linkage disequilibrium, heterozygosity excess, and molecular coancestry methods. In particular, the ABC method performed best with few loci and small sample sizes, while the other estimators required larger sample sizes and at least 13 loci to not underestimate N b. Moreover, according to our N b/N a estimates (values were often ≤0.1), the wood stork colonies evaluated could be facing the loss of genetic diversity. We demonstrate that the combination of genetic and census estimates is a useful approach for monitoring natural breeding bird populations. This methodology has been recommended for populations of rare species or with a known history of population decline to support conservation efforts.

Changes in vegetation cover of the Pantanal wetland detected by Vegetation Index: a strategy for conservation

The Brazilian Pantanal wetland undergoes landscape alterations that can cause impacts on hydrological processes, changing the flood pulse. The objective of this work is to analyse the vegetation cover of the Pantanal in the period of 2000, 2008 and 2015, and to make a projection for 2030. Therefore, NDVI from the sensor MODIS was analysed and the transition matrix was calculated by the DINAMICA EGO. The methods adopted were open sources. The results were worrisome, indicating alterations of the vegetation cover of the Pantanal, with an increase of short vegetation (grasslands or pastures) in the evaluated period. The projection pointed out that in 2030 the Brazilian Pantanal wetland area will be covered by 78% of short vegetation and only 14% of dense (arboreal-shrubby) vegetation. The approach can be a useful tool for conservation of the Brazilian Pantanal wetland.

Rural area of the Brazilian Pantanal wetlands associated with the occurrence of anti-<i>Leishmania</i> spp. antibodies in dogs

Neste trabalho foi realizada uma avaliação sobre a presença de anticorpos anti-Leishmania infantum chagasi em cães domésticos das áreas urbanas e rurais da região do Pantanal brasileiro usando técnicas sorológicas. Um total de 429 cães foram amostrados em três áreas do bioma do Pantanal, incluindo os municípios de Poconé, Santo Antônio de Leverger e Barão de Melgaço, em Mato Grosso, e o município de Corumbá, em Mato Grosso do Sul. A reação de imunofluorescência indireta (RIFI) foi utilizada para detectar anticorpos (ponto de corte de 40) de Leishmania infantum chagasi como antígeno. Devido à possibilidade de reação cruzada entre as espécies do gênero Leishmania, as amostras positivas na RIFI para L. infantum chagasi foram também avaliadas na RIFI utilizando L. amazonensis e L. braziliensis como antígenos. As amostras positivas na RIFI para L. infantum chagasi foram avaliadas utilizando o ensaio de imunoadsorção ligado à enzima (ELISA). Os resultados mostraram a presença de anticorpos contra L. infantum chagasi em 23 (5,36%; IC 95%: 3,50% -8,05%) cães e pelo menos um cão soro-reativo foi encontrado em todos os municípios avaliados neste estudo. Os títulos de anticorpos variaram de 40 a 5.120 e todas as amostras positivas na RIFI foram positivas no ELISA. Entre os 23 cães positivos, nove também reagiram para L. amazonensis e L. braziliensis. A ocorrência de anticorpos anti-L. infantum chagasi em cães foi maior nas áreas rurais (7,06%) do que nas áreas urbanas (2,50%) (P < 0,05). Com base neste estudo, concluímos que cães de áreas rurais do Pantanal tiveram contato com espécies de Leishmania, o que é uma informação relevante, dada a sua importância para a saúde pública.

A new species of Argulus (Crustacea, Branchiura, Argulidae) from the skin of catfish, with new records of branchiurans from wild fish in the Brazilian Pantanal wetland

During a survey conducted in the Cuiabá and Paraguay Rivers in the Brazilian Pantanal wetland, in the states of Mato Grosso and Mato Grosso do Sul, we found branchiurans associated with Pseudoplatystoma reticulatum, Pseudoplatystoma corruscans, Salminus brasiliensis and Zungaro zungaro. These branchiurans correspond to Argulus chiropteroideus sp. n., Argulus multicolor, Argulus nattereri, Argulus pestifer, Dolops carvalhoi and Dolops longicauda. Besides the description of the new species, in this study we also provide important morphological notes for diagnosis of the other species. Specimens of Argulus chiropteroideus sp. n. were collected from skin of P. reticulatum and P. corruscans. They differ from A. multicolor and Argulus chicomendesi, in the shape of the postantennal spines, which is medially convex and has two lateral and one anterior stout tips in the new species, and for having three claviform, digitate spines on the base of the second maxillae (absent in A. multicolor; three conical, short spines in A. chicomendesi). A. chiropteroideus sp. n. do not have an anterior and a posterior spine on first two segments of first antenna, as well as no flagellum on the dorsal surface of the first two pairs of legs, structures present in A. multicolor and A. chicomendesi. The new species also differ from A. multicolor and A. chicomendesi, in the shape and number of sclerites that compound the support rods of the suction cup.

Antibodies Against Sarcocystis neurona, Neospora spp., and Toxoplasma gondii in Horses and Mules From the Northern Pantanal Wetland of Brazil

The present study evaluated the prevalence of antibodies against Sarcocystis neurona, Neospora spp., and Toxoplasma gondii in 547 equids (500 horses and 47 mules) from 25 ranches in the Brazilian Pantanal wetlands. The indirect fluorescent antibody test (IFAT) using the appropriate parasite antigens was used as a screening test, and all positive samples for Sarcocystis spp. and Neospora spp. were subsequently evaluated by the rSnSAG2/4/3 and rNhp29 enzyme-linked immunosorbent assays (ELISAs) for S. neurona and Neospora hughesi, respectively. According to the IFAT, 112 of 547 (20.4%) samples were positive for Sarcocystis spp., 65 (11.8%) were positive for Neospora spp., and 138 (25.2%) for T. gondii. In the follow-up analyses, 33 of 112 Sarcocystis spp. IFAT-positive samples were positive by rSnSAG2/4/3 ELISA, and 5 of 65 Neospora spp. IFAT-positive samples were rNhp29 ELISA positive. Western blot (WB) analysis of a subset of samples confirmed the Sarcocystis rSnSAG2/4/3 ELISA results. In contrast, WB analysis using Neospora antigen did not confirm the rNhp29 ELISA results, and further revealed that only two samples were true positives. Interestingly, the two samples seroreacted against immunodominant antigens of N. hughesi but showed stronger reaction to the same antigens of Neospora caninum in the WB. Our results demonstrate that equids from the Brazilian Pantanal wetlands have antibodies to S. neurona and T. gondii, but antibodies to Neospora spp. are uncommon in these animals.

Late Quaternary Cuiabá megafan, Brazilian Pantanal: Channel patterns and paleoenvironmental changes

Abstract The Brazilian Pantanal wetlands comprise some of the largest Quaternary megafans in South America. The origin of these megafans has been linked to climate changes during the Late Quaternary. This study focuses on the Cuiaba megafan, the second largest megafan of the Pantanal, which has not been studied from the perspective of its basic geomorphology, river channel patterns and sediment deposition ages. Analysis of the channel and floodplain morphology as well as optically stimulated luminescence dating enable us to establish the succession of events that built up the Cuiaba megafan since the last glacial period. Abandoned lobes indicate that a phase of fan aggradation occurred between 48 and 19 ka, with a network of distributary paleochannels suggesting that there was relatively low precipitation and reduced vegetation cover. Subsequently, abrupt changes in discharge and sediment supply triggered the channel incision of the upper fan valley, indicating a degradational phase after the Last Glacial Maximum (

Cyanobacteria diversity in alkaline saline lakes in the Brazilian Pantanal wetland: a polyphasic approach

Fil: Costa, Naila B.. Universidade Federal Do Minas Gerais. Instituto de Ciencias Biologicas. Departamento de Botanica; Brasil

Improving precipitation simulation from updated surface characteristics in South America

Land use and land cover maps and their physical-chemical and biological properties are important variables in the numerical modeling of Earth systems. In this context, the main objective of this study is to analyze the improvements resulting from the land use and land cover map update in numerical simulations performed using the Regional Climate Model system version 4 (RegCM4), as well as the seasonal variations of physical parameters used by the Biosphere Atmosphere Transfer Scheme (BATS). In general, the update of the South America 2007 land use and land cover map, used by the BATS, improved the simulation of precipitation by 10 %, increasing the mean temporal correlation coefficient, compared to observed data, from 0.84 to 0.92 (significant at p < 0.05, Student’s t test). Correspondingly, the simulations performed with adjustments in maximum fractional vegetation cover, in visible and shortwave infrared reflectance, and in the leaf area index, showed a good agreement for maximum and minimum temperature, with values closer to observed data. The changes in physical parameters and land use updating in BATS/RegCM4 reduced overestimation of simulated precipitation from 19 to 7 % (significant at p < 0.05, Student’s t test). Regarding evapotranspiration and precipitation, the most significant differences due to land use updating were located (1) in the Amazon deforestation arc; (2) around the Brazil-Bolivia border (in the Brazilian Pantanal wetlands); (3) in the Northeast region of Brazil; (4) in northwestern Paraguay; and (5) in the River Plate Basin, in Argentina. Moreover, the main precipitation differences between sensitivity and control experiments occurred during the rainy months in central-north South America (October to March). These were associated with a displacement in the South Atlantic convergence zone (SACZ) positioning, presenting a spatial pattern of alternated areas with higher and lower precipitation rates. These important differences occur due to the replacement of tropical rainforest for pasture and agriculture and the replacement of agricultural areas for pasture, scrubland, and deciduous forest.

Markov chains–cellular automata modeling and multicriteria analysis of land cover change in the Lower Nhecolândia subregion of the Brazilian Pantanal wetland

The dynamics of land use/land cover change in the Lower Nhecolândia wetland are marked by deforestation for pasture expansion, resulting in a real threat to the ecological stability. The aim of our work was to analyze the spatial distribution of land cover changes in the Lower Nhecolândia from 1985 to 2013 and to predict changes in trends for 2040. The mapping of land cover changes was developed using Landsat satellite images of 1985, 1999, 2007, and 2013, based on geographic object-based image analysis approach. This study uses integrated Markov chains and cellular automata modeling and multicriteria evaluation techniques to produce transition probability maps and describe the trajectory analysis methodology to construct a continuity of spatial and temporal changes for the wetland. The results of the multitemporal change detection classification show that, from 1985 to 2013, the forest woodland decreased by 6.89% and the grassland class increased by 18.29%. On the other hand, all water bodies showed a reducing trend, while the bare soil class increased compared to 1985, but did not present a regular trend of increase or decrease. From the present day, the trend for the future is a reduction of almost 6.4% by 2040. We found that deforestation actions will be concentrated in the areas with the highest concentration of saline lakes, constituting a serious threat to the natural functioning of this environmental system.