Pantanal Wetland Research Articles

Ecosystem services in the floodplains: Socio-cultural services associated with ecosystem unpredictability in the Pantanal wetland, Brazil

Abstract Ecosystem services do not exist independently from human perceptions and recognition. They are socially, culturally, economically, and environmentally scale- and context-dependent. Socio-cultural services tend to be difficult to evaluate and invisible to policymakers and conservation practitioners. Based on six years’ qualitative analysis of a floodplain fishery in the Pantanal wetland, Brazil, we bring an in-depth understanding of the socio-cultural ecosystem services in the region. We show that the inter- and intra-annual ecosystem dynamics variations in the flood pulse are closely associated with local people's governance structure, identity, and cosmological histories. All of them, to some extent, capture some of the unpredictable changes in the Pantanal. Our study uncovers part of the complex and rich social-cultural ecosystem service created from the interaction between local people and the ecosystem in which they are embedded. We also present the threats faced by these services in the face of current development projects in the Pantanal, such as the Waterway and Hydrometric Dams. We argue that the predicted outcome may jeopardize not only the social-cultural services in the Pantanal, but also the local people themselves and the environment that they are currently protecting.

Taquari Megafan: Estimation of Water Resources in the Pantanal Wetland, Brazil

Taquari Megafan: Estimation of Water Resources in the Pantanal Wetland, Brazil

Influência dos níveis de nutrientes, tempo de viagem e disponibilidade de luz nas concentrações de clorofila-a fitoplanctônica em uma bacia de rio neotropical

Abstract: Aim Knowledge of the factors influencing the biomass of phytoplankton in rivers is important with reference to the characterization of water quality and predicting the effects of environmental change on such ecosystems. The present study quantified the concentrations of chlorophyll-a in the water column of the Miranda River Basin, located in western Brazil, contributing to form the Pantanal Wetland, and attempted to identify the primary environmental influences on the phytoplankton biomass. Methods Temperature, depth, current speed, turbidity, Secchi transparency and concentrations of nutrients, suspended solids and chlorophyll-a were measured at approximate monthly intervals during the course of a year, at five upland and three lowland sites. Relationships between chlorophyll-a and nutrient concentrations, travel times and light availability were examined. Results Nutrient levels were generally low, being oligo- to mesotrophic. High levels of suspended solids were recorded (up to approximately 250 mg.L-1), especially in the rainy season at the upland sites. The latter showed low chlorophyll-a concentrations, while lowland sites, with the exception of one, showed two peaks, one in winter (dry season) and the other in summer (wet season), of 4.9 and 2.4µg.L-1, respectively, coincident with reduced concentrations of suspended solids. Conclusions The low nutrient levels recorded may have been due to the main land use being cattle rearing. The high solids concentrations found may have been due to the degradation of native vegetation, especially riparian, that has occurred over the past decades. Travel times of approximately three to four days may have been a factor in retarding algal abundance in the upland sites, as opposed to approximately ten days in the lowland sites, where light limitation may have been a factor reducing algal growth.

A imersão em água e o armazenamento de um ano influenciam a germinação dos pirênios de Copernicia alba Morong, uma palmeira de um bioma alagado neotropical

ABSTRACT Palm seeds are known for displaying dormancy and a thick endocarp that delays germination and embryo growth, but water treatments may accelerate their germination process. Additionally, ex-situ conservation of arecaceae species may cause loss of seed viability over time. Data on seed dormancy and storage have been neglected for many native palm species in Brazil. Therefore, we investigated the effect of water treatments and one-year storage on the germination of Copernicia alba Morong, a palm tree from the Brazilian Pantanal wetland. Fresh and stored pyrenes were immersed in water (at room temperature for 24, 48, and 72h) and in hot water (~75°C for 5 and 10-min). Fresh pyrenes germinated up to 84% in control, reaching 100% after water immersion for 48 and 72h. One-year storage reduced germination by almost 50%, but water immersion slightly increased the germination of stored pyrenes. Hot water decreased germination for both fresh and stored pyrenes. Seeds of C. alba may be classified as orthodox seed storage behavior. Taken all together, water treatments at room temperature improved the germination of the pyrenes. In contrast, long-term seed storage and hot-water treatments may jeopardize germination.

Extreme citizen science: Lessons learned from initiatives around the globe

AbstractThe participation of communities living in high conservation value areas is increasingly valued in conservation science and practice, potentially producing multiple positive impacts on both biodiversity and local people. Here, we discuss important steps for implementing a successful extreme citizen science project, based on four case studies from conservation projects with Pantaneiro fishers living in Brazilian Pantanal wetland, Baka hunter‐gatherers and Fang farmers in lowland wet forest in Cameroon, Maasai pastoralists in Kenya, and Ju|'hoansi rangers living in the semiarid deserts of Namibia. We highlight the need for a high level of trust between the target communities and project developers, communities' right to choose the data they will be collecting, and researchers' openness to include new tools that were not initially planned. By following these steps, conservation scientists can effectively create bottom‐up collaborations with those living on the frontlines of conservation through community‐led extreme citizen science.

Distance sampling surveys reveal 17 million vertebrates directly killed by the 2020\u2019s wildfires in the Pantanal, Brazil

Anthropogenic factors have significantly influenced the frequency, duration, and intensity of meteorological drought in many regions of the globe, and the increased frequency of wildfires is among the most visible consequences of human-induced climate change. Despite the fire role in determining biodiversity outcomes in different ecosystems, wildfires can cause negative impacts on wildlife. We conducted ground surveys along line transects to estimate the first-order impact of the 2020 wildfires on vertebrates in the Pantanal wetland, Brazil. We adopted the distance sampling technique to estimate the densities and the number of dead vertebrates in the 39,030 square kilometers affected by fire. Our estimates indicate that at least 16.952 million vertebrates were killed immediately by the fires in the Pantanal, demonstrating the impact of such an event in wet savanna ecosystems. The Pantanal case also reminds us that the cumulative impact of widespread burning would be catastrophic, as fire recurrence may lead to the impoverishment of ecosystems and the disruption of their functioning. To overcome this unsustainable scenario, it is necessary to establish proper biomass fuel management to avoid cumulative impacts caused by fire over biodiversity and ecosystem services.

Improving Representation of Tropical Wetland Methane Emissions With CYGNSS Inundation Maps

AbstractWetlands are the single largest source of methane to the atmosphere and their emissions are expected to respond to a changing climate. Inaccuracy and uncertainty in inundation extent drives differences in modeled wetland emissions and impacts representation of wetland emissions on inter‐annual and seasonal time frames. Existing wetland maps are based on optical or NIR satellite data obscured by clouds and vegetation, often leading to underestimates in wetlands extent, especially in the Tropics. Here, we present new inundation maps based on the Cyclone Global Navigation Satellite System (CYGNSS) satellite constellation, operating in L‐band that is not impacted by clouds or vegetation, providing reliable observations through canopy and cloudy periods. We map the temporal and spatial dynamics of the Pantanal and Sudd wetlands, two of the largest wetlands in the world, using CYGNSS data and a computer vision algorithm. We link these inundation maps to methane fluxes via WetCHARTs, a global wetland methane emissions model ensemble. We contrast CYGNSS‐modeled methane emissions with WetCHARTs standard runs that use monthly rainfall data from ECMWF re‐analysis (ERA5), as well as the commonly used SWAMPS wetland maps. We find that the CYGNSS‐based inundation maps modify the methane emissions in multiple ways. The seasonality of inundation and methane emissions is shifted by two months because of the lag in wetland recharge following peak rainfall. Both inundation and methane emissions also respond non‐linearly to wet‐season precipitation totals, leading to large interannual variability in emissions. Finally, the annual magnitude of emissions is found to be greater than previously estimated.

Reconciling biome-wide conservation of an apex carnivore with land-use economics in the increasingly threatened Pantanal wetlands

Conservation of carnivores involves finding solutions to minimize habitat loss and human-wildlife conflict. Understanding the nature of land-use economics can allow us to mitigate both threats. In the Pantanal, the two main economic activities are cattle ranching and ecotourism, each of which directly and indirectly affect the persistence of jaguars (Panthera onca). To understand how the geography of these economic activities is related to jaguar populations, we developed a jaguar distribution model (JDM), livestock density model, and ecotourism lodge density model for the Pantanal. Due to the recent wildfires within the Pantanal, we also assess the impact of burnt areas that are suitable for jaguars, cattle ranching, and tourism. Our JDM indicate that 64% of the Pantanal holds suitable habitat for jaguars. However, jaguar habitat suitability was positively correlated with ecotourism, but negatively correlated with areas most suitable for intensive cattle-ranching. This demonstrates a biome-wide scenario compatible with jaguar conservation. Of particular concern, recent wildfires overlap most suitable areas for jaguars. If wildfires become increasingly frequent, this would represent a serious threat to jaguars and many other wildlife populations. We emphasize the global importance of the Pantanal wetland ecoregion as a key stronghold for long-term jaguar conservation.

Processes and rates of formation defined by modelling in alkaline to acidic soil systems in Brazilian Pantanal wetland

Within a soil system, it is generally difficult to relate the observed secondary phases and their spatial distribution to past or current processes. Geochemical modelling can help to identify present-days processes and to quantify formation rates if the system is sufficiently constrained. Here we used the PHREEQC model for this purpose, applying it to soil alkaline to acidic soil systems in the Nhecolândia area. A large amount of data was available, but scientific questions remained opened. We carried out a complementary field study to clarify a key point necessary for modelling, confirming the disconnection between two types of groundwater, perched, alkaline and deep, acidic. Our simulations showed that the observed soil system corresponds to the current biogeochemistry and that paleoclimatic genetic hypotheses are unnecessary. We found that the ridge soil formation rate ranges from 396 to 638 kg ha−1 y−1, depending on hypotheses. We showed that the downslope soils act as buffers to store labile species during the dry season, allowing alkalinity to be maintained from one year to the next. At least 125 y were necessary to obtain downslope alkaline lakes, and this alkaline nature can quickly disappear after changing drainage conditions. We explained how hyperacidic horizons (pH < 4) can neighbor alkaline horizons (pH > 10) with a sharp contact. When correctly informed, geochemical modelling appeared as an effective tool to answer questions about soil processes.

Comparative analysis of climate and topography in Chaco and Oriental, Paraguay

The article reports the issues corresponding to the climate variability and possibility of droughts in spatially distinct regions of Paraguay, the Chaco and the Oriental (Paraná Basin). Based on the GMT scripting approach and high-resolution datasets from the TerraClimate and GEBCO, the study examined the extent of the annual climate and environmental variables over Paraguay in 2020: extreme temperatures, wind speed, precipitation, soil moisture, evapotranspiration, Palmer's Drought Severity Index (PDSI), vapour pressure deficit (VPD) and the topography of the country. The environmental and climate parameters demonstrated spatial variability in the Dry Chaco with notable differences in Gran Chaco and Chaco Boreal, wetlands of Pantanal, and tropical rainforests in east of the Paraguay. Besides climate analysis, technical snippets from the GMT scripts regarding the mapping techniques and data processing were explained and commented. Research results show that actual evapotranspiration reaches maximal values in the Paraná Basin (180 mm/yr), and has peaks along the Pilcomayo river (140-150 mm/yr) which well coincides with the soil moisture; the PDSI values are maximal in Chaco Boreal and Gran Chaco; the temperatures are the highest in the N and NW regions of Paraguay; the highest VPD (over 2.0) corresponds to the Chaco Boreal.

Scientometric analysis of Ecotourism in the Pantanal wetlands

This scientometric study aimed to outline an overview of studies on ecotourism in the Pantanal published between 1990 and 2020. In this sense, studies published in the form of books, book chapters and scientific articles in journals were selected. Data were collected using the Web of Science, Scopus and, Science Direct databases, as well as the Google Scholar tool. We identified 36 published works on the subject. In 2020, seven studies were published, this being the year with the largest number of publications. 84% (n = 30) of the works were published in scientific journals, 8% (n = 3) in the form of book chapters and 8% (n = 3) in the form of books. Altogether, 92 authors wrote on the subject, but only 13 of them published at least two works. The highlights were C.J.R. Alho, with 4 publications, followed by R. Hoogesteijn and F. R. Tortato, with 3 each. Among the journals, Ecological Economics was the only one to present 3 articles. The most discussed topics were Ecotourism, Conservation, Biodiversity and Pantanal. Similarly, in the works’ keyword network, the words Pantanal, Conservation, Biodiversity and Tourism stood out.Finally, it is suggested that research institutions and Brazilian tourism associations should increase their partnerships to strengthen the research process on ecotourism in the Pantanal.

In situ arsenic speciation at the soil/water interface of saline-alkaline lakes of the Pantanal, Brazil: A DGT-based approach

Arsenic (As) is a naturally occurring element in the Earth's crust, exhibiting toxicity towards a wide range of living organisms. Its properties and environmental dynamics are strongly regulated by its speciation, and the species As(III) and As(V) are the most commonly found in environmental systems. Recently, high concentrations of As were found in saline-alkaline lakes of the Pantanal (Brazil), which is the largest wetland area in the world. Therefore, we evaluated As contamination and its redox speciation (As(III) and As(V)) at the soil/water interface of biogeochemically distinct saline-alkaline lakes of Pantanal wetlands (Brazil). Both conventional sampling and in situ diffusive gradients in thin films (DGT) technique were employed. Zirconium oxide and 3-mercaptopropyl were used as ligand phases in DGT to selectively bind As species. High concentrations of total dissolved As in a shallow water table were found (<2337.5 μg L−1), whereas levels in soils were up to 2.4 μg g−1. Distinct scenarios were observed when comparing speciation analysis through spot sampling and DGT. Considering spot sampling, As(V) was the main species detected, whereas As(III) was only detected in only a few samples (<4.2 μg L−1). Conversely, results obtained by DGT showed that labile As(III) dominated arsenic speciation at the soil/water interface with levels up to 203.0 μg L−1. Coupling DGT data and DGT induced fluxes in sediments and soils model allowed obtaining kinetic data, showing that the soil barely participated in the arsenic dynamics on the shore of the lakes, and that this participation depends on the evapoconcentration process occurring in the region. Therefore, soil acts like a nonreactive matrix depending on the natural concentration process. In addition, our results reinforced the different geochemical characteristics of the studied saline-alkaline lakes and highlights the importance of robust passive sampling techniques in the context of metal/metalloid speciation in environmental analysis.

Methods for the characterization of activity patterns in elusive species: the giant armadillo in the Brazilian Pantanal

AbstractThe behavioral study of elusive species, which often cannot be directly observed in the wild, is based on the use of animal monitoring technologies. Here, we evaluate the performance of four methods applied simultaneously on a single population to detect and characterize the activity behavior of elusive species, using the giant armadillo Priodontes maximus as a model. GPS tagging, accelerometer, and camera trap array data were used to characterize general activity patterns, while camera traps placed in front of burrows in use were used to define activity duration, onset, and termination times. Circular kernel probability density functions were used to characterize activity patterns with each data set and the overlap coefficient Δ4 was used to characterize the similarity between them. We gathered data from 53 armadillos during 9 years in the Pantanal wetlands of Brazil. Activity duration estimates showed significant variation among monitoring methods but were generally short (4.5–6 h on average). Overall, the estimates of activity timing provided by the methods used were relatively similar (&gt;75% Δ4 overlap) and pointed to a nocturnal activity pattern. Armadillos left their burrows mainly in the first hours after sunset, and terminated their activity mainly between midnight and 4 am. However, the camera trap array provided a later activity onset and peak estimates for the species when compared to other methods. The species spends 75–80% of its time underground and accelerometer data shows that armadillos are not active and do not feed while underground, pointing to a fossorial behavior for the species. Although researchers should be aware of the small biases that can emerge from some of the methods, the general similarities among patterns indicates that researchers can choose among the ever‐increasing number of animal monitoring technologies depending on their research question and constraints.

Quantifying bite force in coexisting tayassuids and feral suids: a comparison between morphometric functional proxies and in vivo measurements.

BackgroundMeasuring mammals’ bite force in laboratory conditions is not a simple task, let alone on wild medium-sized mammals in the field. Thus, morphometric-proxies are usually used to infer morphofunctional properties of musculoskeletal features. For instance, the study of bite force-indexes suggests that different capacities to crack food items reduce the competition between coexistent collared and white-lipped peccaries (Pecari tajacu and Tayassu pecari). The presence of exotic feral hogs (Sus scrofa) in peccaries’ endemic areas gives rise to new ecological interactions between them. An example is the Brazilian Pantanal wetland, where ecomorphological mechanisms may play a role in their ecological relations. Taking this scenario as a case of study, we aimed to verify if the morphometric-proxies are de facto reliable tools, by comparing bite forces-indexes with the in vivo bite forces of these species.MethodsWe captured 21 collared and white-lipped peccaries and feral hogs in the Brazilian Pantanal to assess their bite force at first molar. The Bite Force Measuring Tube (BiTu) is a robust and simple mechanical device designed to be used in field conditions. Only 11 individuals successfully bit the BiTu before being released. Their body measurements were compared and correlated with their bite force. The in vivo bite forces were compared with bite force-indexes of two papers based on independent morphometric methods and datasets: Sicuro & Oliveira (2002) used classic morphometrics to infer the bite forces of these three species in the Brazilian Pantanal, and Hendges et al. (2019) used geometric morphometrics to compare bite forces-indexes and feeding habits of the extant peccary species. The results of all species were standardized (Z-curves) according to each method. Doing so, we obtained comparable dimensionless comparable values but maintaining the differences between them.ResultsThe morphometric-proxies-based studies presented similar results: collared peccaries present weaker bites than white-lipped peccaries and feral hogs, while these two species presented no significant differences in their bite force-indexes. The in vivo bite force results suggest the same relations predicted by the morphometric models, including the high variation among the feral hogs. We found a significant correlation between the individuals’ weight (kg) and their actual bite force (N) but no significant correlations with the head length.ConclusionsThe BiTu proved to be a functional and low-cost tool to measure bite force in field conditions. The in vivo results presented a good correspondence with the predictions based on morphometric-proxies by Sicuro & Oliveira (2002) and Hendges et al. (2019). The results denote that these studies succeed in capturing the biomechanical signal of the three species’ skull-jaw systems. This empirical validation confirms that these morphometric-proxies analyses are reliable methods to ecomorphological and evolutionary inferences.

Characterization of shelters of the giant otter (Pteronura brasiliensis, Mammalia, Carnivora, Mustelidae) in the pantanal wetlands, state of Mato Grosso, Brazil

The giant otter (Pteronura brasiliensis) is an endangered mammal that occupies aquatic environments, especially in the Amazon Rainforest and Pantanal wetlands in South America. The species uses shelters (dens and campsites), such as burrowed tunnels and tangles of branches and roots along watercourses, where it feeds mainly on fishes. In Espírito Santo Creek (northern portion of the Pantanal wetlands in the state of Mato Grosso, Brazil), 60 shelters (45 dens and 15 campsites) were identified and georeferenced during 12 fieldtrips between 2002 and 2003. The density was 1.8 dens/km. The shelters were significantly found in locations with partial (35%) or complete (55%) plant cover. The dens were dug mainly in soil associated with roots located, on average, 4.4 m in distance and 2.4 m in height in relation to the waterline. The campsites had a significantly smaller distance and height compared to the dens. The greater density of dens in the study area underscores the need for conserved environments with little human interference for the protection of giant otter populations. The vegetal coverage of riparian forests and the occurrence of ravines along Espírito Santo Creek offer greater protection to the shelters, hindering the access of predators to the interior of the shelter. Studies integrating biological and ecological knowledge with social participation in areas of occurrence of the giant otter are fundamental to the conservation of the species and its habitat in the Pantanal wetlands of Mato Grosso, Brazil.

Screening of 20 Pantanal Wetland Plants for Anti-Candida Activity using HPLC-DAD-MS/MS and Bioautography to Characterize Active Compounds

AbstractThe Pantanal wetland harbors a rich flora with uncharted pharmacological potential. This study evaluated 20 Brazilian Pantanal plants against Candida albicans, C. parapsilosis, C. tropicalis, and C. krusei. Fungal susceptibility was determined by agar diffusion and broth microdilution; active compounds were identified by bioautography and HPLC-DAD-MS/MS. Sesbania virgata, Polygala molluginifolia, and Cantinoa mutabilis extracts and their chloroform and ethyl acetate (EtOAc) fractions exhibited the best activity against all Candida species tested. The EtOAc fraction of P. molluginifolia proved to be more efficient in inhibiting C. parapsilosis and C. krusei growth (Minimum inhibitory concentration of 125 and 62.5 μg/mL, respectively). Bioautography of this fraction revealed two active bands, characterized by HPLC-DAD-MS/MS as a mixture of podophyllotoxin derivatives blumenol, besides some flavonoids. This work demonstrated antifungal potential of P. molluginifolia podophyllotoxin derivatives and the versatility of bioautography with HPLC-DAD-MS/MS to identify the bioactive compounds.

Mineralogy and genesis in an alkaline soil system in the southern Pantanal wetland, Brazil

The genesis of clays in Pantanal soils is influenced by parent material, water seasonality and elevated temperatures, resulting in soils with attributes not so common in other tropical regions. This research aimed to study the genesis of minerals in the clay fraction present in three soil profiles developed from carbonate sediments in Pantanal of the State of Mato Grosso do Sul, Brazil. Three trenches were excavated, and the soils were morphologically described and classified according to WRB in Chernozem (profiles P1 and P3) and Gleysol (P2). In addition, deformed samples from all soil horizons were sampled and used in physical, chemical, and mineralogical analyses. Clay fraction obtained from the diagnostic subsurface horizons of the profiles was submitted to identification of the mineral phases using X-ray diffraction, morphological analysis in a scanning electron microscope and microchemical analysis using energy dispersive X-ray spectroscopy. In the three profiles, the presence of interlayered minerals of kaolinite-smectite and illite-smectite; quartz and calcite in profile P3, was confirmed in the clay fraction. The clays from the three profiles presented high levels of SiO2 (ranging from 35.4 to 56.7%). The clays from profiles P1 and P2 presented high levels of Al2O3 (P1 = 24.6% and P2 = 15.2%), Fe2O3 (P1 = 14.0% and P2 = 11.8%), which suggests the formation of dioctahedral clay and illite rich in Fe. The high levels of MgO (11.1%) and Fe2O3 (7.2%) in clays of the P3 profile indicated the presence of trioctahedral Mg-smectite and illite rich in Fe. In the studied soils, the condition of moderate to imperfect drainage, water from the water table rich in cations and the alkaline environments of soils, constitutes the principal factor responsible for the current dynamics of neoformation of dioctahedral illite rich in Fe and trioctahedral Mg-smectite and dissolution of kaolinite.

Niche partitioning in small mammals: interspecific and biome-level analyses using stable isotopes

Abstract Small mammal assemblages from South America provide a unique opportunity to measure coexistence and niche partitioning between marsupials and placentals. We tested how these two major clades partition environmental resources by comparing stable isotopic ratios of similar sized Didelphidae and Sigmodontinae in four Brazilian biomes: Pampas grassland, Pantanal wetland, Cerrado woodland savanna, and Atlantic Forest. Generally, didelphid isotopic niche follows a scaling law, because we found an association between δ15N enrichment and body mass. Sigmodontines that primarily partition the environment via forest strata showed a greater intake of C4 or/and crassulacean acid metabolism (CAM) plants than didelphids, as reflected by their wider trophic niche. Values of δ13C were highest in savannas and grasslands (Cerrado and Pampas biomes), and values of δ15N were highest in the Atlantic Forest (in sigmodontines) and Pampas (in didelphids). While assessing patterns between the two major Brazilian biomes (Atlantic Forest and Cerrado), we found evidence of a broader trophic niche for both clades in the Cerrado. In the Atlantic Forest, niche occupation by Didelphidae was completely enclosed within the Sigmodontinae trophic niche. Both clades showed less overlap in the Cerrado, a less productive environment. Our results highlight the importance of a comparative framework and the use of stable isotopes for testing ecological questions related to how small mammalian communities partition their niche.

Revisiting the drivers of acoustic similarities in tropical anuran assemblages.

Acoustic signaling is key in mediating mate choice, which directly impacts individual fitness. Because background noise and habitat structure can impair signal transmission, the acoustic space of mixed-species assemblages has long been hypothesized to reflect selective pressures against signal interference and degradation. However, other potential drivers that received far less attention can drive similar outputs on the acoustic space. Phylogenetic niche conservatism and allometric constraints may also modulate species acoustic features, and the acoustic space of communities could be a side-effect of ecological assembly processes involving other traits (e.g., environmental filtering). Additionally, the acoustic space can also reflect the sorting of species relying on public information through extended communication networks. Using an integrative approach, we revisit the potential drivers of the acoustic space by addressing the distribution of acoustic traits, body size, and phylogenetic relatedness in tropical anuran assemblages across gradients of environmental heterogeneity in the Pantanal wetlands. We found the overall acoustic space to be aggregated compared with null expectations, even when accounting for confounding effects of body size. Across assemblages, acoustic and phylogenetic differences were positively related, while acoustic and body size similarities were negatively related, although to a minor extent. We suggest that acoustic partitioning, acoustic adaptation, and allometric constraints play a minor role in shaping the acoustic output of tropical anuran assemblages and that phylogenetic niche conservatism and public information use would influence between-assemblage variation. Our findings highlight an overlooked multivariate nature of the acoustic dimension and underscore the importance of including the ecological context of communities to understand drivers of the acoustic space.

Do fire and flood interact to determine forest islet structure and diversity in a Neotropical wetland?

Flood and fire act as ecological filters which can interact to shape forest structure and species composition. Our objective was to investigate how the interaction between fire and flood influences richness, abundance, basal area and species composition of the tree community and the monodominant belts of Attalea phalerata Mart. in forest islets of the Pantanal wetland. We used satellite images to find 12 forest islets without fire events from 1998 to 2014, and 12 forest islets burned only once in the same period in a fire event in 2009. In these forest islets, we set up a transect with 10 to 14 contiguous 5 × 10 m plots and sampled all trees with a diameter at breast height of ≥ 4.7 cm. We also measured the watermark height. Flooding influenced species richness and abundance, increased toward wetter areas of the forest islet flood gradient. In contrast, the interaction between fire and flood inverted that trend, with richness and abundance increasing in flood-free areas. Total basal area increases in the more flooded areas of the gradient. The fire or the interaction between fire and flooding did not influence the basal area. The relative abundance of A. phalerata increased with flood level and even more under the fire-flood interaction. We conclude that the interaction between fire and flood influences forest islet structure and species composition; moreover, it favors A. phalerata monodominance.