Arid Biomes Research Articles

Asymmetric responses of litter decomposition to altered precipitation: Double evidence from field experiments and global synthesis

<p>Altered precipitation regimes as a result of global climate change have significant implications for ecosystem processes, such as the decomposition of litter, a vital process in carbon (C) and nutrient cycling in terrestrial ecosystems. However, the effects of altered precipitation regimes on litter decomposition across humid and arid biomes remain unresolved. To address this knowledge gap, we conducted a comparative analysis using data from a geographically replicated precipitation‒manipulation field experiment that studied litter decomposition and a global meta-analysis of 778 paired observations from 207 peer-reviewed articles. Our findings indicated that the litter decomposition constant (<i>k</i>) was 7.7–31.3% greater under increased precipitation and 10.0–41.0% lower under decreased precipitation than under the control treatments. Litter decomposition, soil moisture, microbial biomass, and enzymatic activity had stronger responses to increased precipitation in the arid region and to decreased precipitation in the humid region, which was consistent with the double asymmetric model. A global meta-analysis also confirmed the asymmetrical effects of altered precipitation regimes on litter decomposition between humid and arid regions. Our results highlight the potential asymmetry in the effects of altered precipitation regimes on C and nutrient cycling between humid and arid terrestrial ecosystems.</p>

The hind limb of Octodontidae (Rodentia, Mammalia): Functional implications for substrate preferences

Octodontids are South American caviomorph rodents endemic to mesic and arid biomes displaying a wide range of substrate preferences, from terrestrial to subterranean habits. However, the hind limb morphology of these rodents remain relatively poorly understudied, particularly from an ecomorphological perspective. To investigate the association between hind limb morphology and substrate preference—epigean, semifossorial, fossorial, and subterranean— this study analyzed six skeletal measurements of femur and tibia, along with five morphological indices. We employed phylogenetic mapping, allometry, and multivariate analyses (Phylogentic Flexible Discriminant and Principal Component analyses) on log-transformed variables and indices. The results suggest that the epigeans and subterraneans possess hind limb skeletal features that enhance their mechanical capabilities, which are advantageous for their respective lifestyles. However, in the absence of clear behavioral adaptations or associations, the functional habits of Octodontidae do not requires significant structural modifications of the proximal bones of the hind limbs. These results indicate that understanding the form-function relationship in octodontids requires direct field or laboratory observations of behavior and environmental interactions, highlighting the limitations of current research without such data.

Increasing Sensitivity of Tree Radial Growth to Precipitation

AbstractThe sensitivity of tree growth to precipitation regulates their responses to drought, and is a crucial metric for predicting ecosystem dynamics and vulnerability. Sensitivity may be changing with continuing climate change, yet a comprehensive assessment of its change is still lacking. We utilized tree ring measurements from 3,044 sites, climate data and CO2 concentrations obtained from monitoring stations, combined with dynamic global vegetation models to investigate spatiotemporal changes in the sensitivity over the past century. We observed an increasing sensitivity since around 1950. This increased sensitivity was particularly pronounced in arid biomes due to the combined effect of increased precipitation and elevated CO2. While elevated CO2 reduced the sensitivity of the humid regions, the intensified water pressure caused by decreased precipitation still increased the sensitivity. Our findings suggest an escalating vulnerability of tree growth to precipitation change, which may increase the risk of tree mortality under future intensified drought.

Volumetric and energy production assessment of wood in managed forest in the Brazilian arid biome

There is a growing demand for wood products from forests located in dry regions, which includes the Caatinga, a biome in Northeast Brazil. This study evaluates the relationship between volumetric production, energy potential, and the rotation cycle. Information was collected from forest stands in different stages of regeneration located in an arid region of Brazil. Based on the forest management plan, four fields were selected with post-logging ages of 9, 11, 13, and 16 years. This inventory recorded circumference at chest height, circumference at base height, total height, volume, stored energy, technical cutting age, and rainfall index. The results showed that the species that presented the most significant quantity of stems did not always correspond to those that obtained the most significant amount of biomass. The technical cutting age was determined at 16 years, aiming to maximize wood utilization. Regarding energy density, the 9-year-old field reached 7,281 kcal ha-1, the 11-year-old field obtained 14,448 kcal ha-1, the 13-year-old field recorded 41,526 kcal ha-1, and the 16-year-old field reached 98,190 kcal ha-1. The species that contributed most to energy accumulation included Mimosa tenuiflora with 3,740 kcal m–³, Piptadenia stipulacea with 3,271 kcal m-3, and Cenostigma pyramidale with 3,101 kcal m-3.

Water canals may promote large-scale defaunation of the Gran Chaco

In the Gran Chaco, one of the most biodiverse, yet imperiled, arid biomes in the world, open-to-air concrete water canals may threaten wildlife via drowning and habitat fragmentation, although these effects are usually overlooked. We performed field surveys and local people interviews along 250 km of canals in the Gran Chaco ecoregion of Argentina during austral spring and summer (six months). We documented 207 drowned individuals of 35 wildlife species, but more realistic estimations could increase this number to the thousands. Six species of conservation concern drowned in the canal, and eight of the drowned species have decreasing population trends. Drownings in some mammal species decreased with time without any mitigation measures implemented at the canal yet, suggesting an ongoing, large-scale population reduction due to this high mortality rate. Since mitigation measures applied in other regions were not effective to stop drowning and population isolation, these infrastructures should be avoided in arid environments worldwide.

Reconstructing monthly 0.25° terrestrial evapotranspiration data in a remote arid region using Bayesian-driven ensemble learning method

This study presents a Bayesian-driven ensemble learning framework to minimize errors in evapotranspiration (ET) data assimilation, thereby generating a continuous-scale ET estimation with improved accuracy for the data-scarce arid Central Asia (CA). Five state-of-the-art gridded ET products were extensively tested and utilized to reconstruct new long-term ET data at grid scale, including two Global Land Data Assimilation System (GLDAS)-Land Surface Models (LSM) (Catchment and NOAH), two reanalysis products (European Centre for Medium-Range Weather Forecasts Reanalysis 5 (ERA5) and Modern-Era Retrospective Analysis for Research and Applications – ver. 2 (MERRA2)), along with the Global Land Evaporation Amsterdam (GLEAM) satellite ET product ver. 3.6b. Taylor Skill Score was employed to evaluate the input gridded ET datasets, using in situ measurements across four arid biomes — cropland, shrubland, farmland, and grassland —as benchmarks. Bayes-Markov Chain Monte Carlo (Bayes-MCMC)-derived logarithmically transformed predictors from the posterior ensemble anomalies were standardized to resolve the mismatches in the cumulative distribution functions of ET data relating to the in situ observations. We found that the constrained residual errors were more profound between 45th and 95th percentiles for the rescaled total ET anomalies across all the input ET datasets at 95 % confidence interval. Moreover, the weighted ensemble estimates derived from the Bayes-MCMC were instrumental in correcting ET anomalies, leading to the robust reconstruction of a more reliable ensemble mean ET data for Central Asia (CAETens) at monthly temporal and 0.25° spatial resolutions, spanning from 2003 to 2020. Overall, CAETens exhibited superior performance, achieving the highest averaged Kling-Gupta Efficiency of 0.75 and registering the lowest Root Mean Square Error of 6.85 mm/m compared to the standalone gridded ET products. Comparisons of spatial distributions of fine-scale features, and evaluations using standard metrics revealed that all ET products varied significantly (p < 0.05) by biome types. Remarkably, only CAETens exhibited a reasonable low positive bias and pronounced ability to resolve the complex spatiotemporal patterns associated with the input gridded ET products. The study bridges the gap in continuous ET monitoring for sustainable water resources management in CA.

Wetness severity increases abrupt shifts in ecosystem functioning in arid savannas.

The accelerating pace of climate change has led to unprecedented shifts in surface temperature and precipitation patterns worldwide, with African savannas being among the most vulnerable regions. Understanding the impacts of these extreme changes on ecosystem health, functioning and stability is crucial. This paper focuses on the detection of breakpoints, indicative of shifts in ecosystem functioning, while also determining relevant ecosystem characteristics and climatic drivers that increase susceptibility to these shifts within the semi-arid to arid savanna biome. Utilising a remote sensing change detection approach and rain use efficiency (RaUE) as a proxy for ecosystem functioning, spatial and temporal patterns of breakpoints in the savanna biome were identified. We then employed a novel combination of survival analysis and remote sensing time series analysis to compare ecosystem characteristics and climatic drivers in areas experiencing breakpoints versus areas with stable ecosystem functioning. Key ecosystem factors increasing savanna breakpoint susceptibility were identified, namely higher soil sand content, flatter terrain and a cooler long-term mean temperature during the wet summer season. Moreover, the primary driver of changes in ecosystem functioning in arid savannas, as opposed to wetter tropical savannas, was found to be the increased frequency and severity of rainfall events, rather than drought pressures. This research highlights the importance of incorporating wetness severity metrics alongside drought metrics to comprehensively understand climate-ecosystem interactions leading to abrupt shifts in ecosystem functioning in arid biomes. The findings also emphasise the need to consider the underlying ecosystem characteristics, including soil, topography and vegetation composition, in assessing ecosystem responses to climate change. While this research primarily concentrated on the southern African savanna as a case study, the methodological robustness of this approach enables its application to diverse arid and semi-arid biomes for the assessment of climate-ecosystem interactions that contribute to abrupt shifts.

A direct PCR approach with low-biomass insert opens new horizons for molecular sciences on cryptogam communities.

Molecular sequence data have transformed research on cryptogams (e.g., lichens, microalgae, fungi, and symbionts thereof) but methods are still strongly hampered by the small size and intermingled growth of the target organisms, poor cultivability and detrimental effects of their secondary metabolites. Here, we aim to showcase examples on which a modified direct PCR approach for diverse aspects of molecular work on environmental samples concerning biocrusts, biofilms, and cryptogams gives new options for the research community. Unlike traditional approaches, this methodology only requires biomass equivalent to colonies and fragments of 0.2 mm in diameter, which can be picked directly from the environmental sample, and includes a quick DNA lysis followed by a standardized PCR cycle that allows co-cycling of various organisms/target regions in the same run. We demonstrate that this modified method can (i) amplify the most widely used taxonomic gene regions and those used for applied and environmental sciences from single colonies and filaments of free-living cyanobacteria, bryophytes, fungi, and lichens, including their mycobionts, chlorobionts, and cyanobionts from both isolates and in situ material during co-cycling; (ii) act as a tool to confirm that the dominant lichen photobiont was isolated from the original sample; and (iii) optionally remove inhibitory secondary lichen substances. Our results represent examples which highlight the method's potential for future applications covering mycology, phycology, biocrusts, and lichenology, in particular.IMPORTANCECyanobacteria, green algae, lichens, and other cryptogams play crucial roles in complex microbial systems such as biological soil crusts of arid biomes or biofilms in caves. Molecular investigations on environmental samples or isolates of these microorganisms are often hampered by their dense aggregation, small size, or metabolism products which complicate DNA extraction and subsequent PCRs. Our work presents various examples of how a direct DNA extraction and PCR method relying on low biomass inserts can overcome these common problems and discusses additional applications of the workflow including adaptations.

Untangling the Causal Links between Satellite Vegetation Products and Environmental Drivers on a Global Scale by the Granger Causality Method

The Granger Causality (GC) statistical test explores the causal relationships between different time series variables. By employing the GC method, the underlying causal links between environmental drivers and global vegetation properties can be untangled, which opens possibilities to forecast the increasing strain on ecosystems by droughts, global warming, and climate change. This study aimed to quantify the spatial distribution of four distinct satellite vegetation products’ (VPs) sensitivities to four environmental land variables (ELVs) at the global scale given the GC method. The GC analysis assessed the spatially explicit response of the VPs: (i) the fraction of absorbed photosynthetically active radiation (FAPAR), (ii) the leaf area index (LAI), (iii) solar-induced fluorescence (SIF), and, finally, (iv) the normalized difference vegetation index (NDVI) to the ELVs. These ELVs can be categorized as water availability assessing root zone soil moisture (SM) and accumulated precipitation (P), as well as, energy availability considering the effect of air temperature (T) and solar shortwave (R) radiation. The results indicate SM and P are key drivers, particularly causing changes in the LAI. SM alone accounts for 43%, while P accounts for 41%, of the explicitly caused areas over arid biomes. SM further significantly influences the LAI at northern latitudes, covering 44% of cold and 50% of polar biome areas. These areas exhibit a predominant response to R, which is a possible trigger for snowmelt, showing more than 40% caused by both cold and polar biomes for all VPs. Finally, T’s causality is evenly distributed amongst all biomes with fractional covers between ∼10 and 20%. By using the GC method, the analysis presents a novel way to monitor the planet’s ecosystem, based on solely two years as input data, with four VPs acquired by the synergy of Sentinel-3 (S3) and 5P (S5P) satellite data streams. The findings indicated unique, biome-specific responses of vegetation to distinct environmental drivers.

Paleoenvironmental models for Australia and the impact of aridification on blindsnake diversification

AbstractAimShifts in diversification rates of Australian flora and fauna have been associated with aridification, but the relationship between diversification rates and aridity has never been quantified. We employed multiple approaches to reconstruct paleoenvironments of Australia for the first time. We used this information, and phylogenetic‐based analyses, to explore how changes in temperature and increasing aridity during the Neogene influenced the diversification of the Australian blindsnakes. We tested whether diversification rates differ between arid‐adapted and mesic‐adapted lineages.TaxonTyphlopidae, Anilios blindsnakes.LocationAustralia.Materials and MethodsWe estimated the historical biogeography of blindsnakes using BioGeoBEARS. We synthesised multiple approaches to reconstruct paleotemperature and paleoaridity of Australia during the Neogene. We fitted several birth‐death models and estimated diversification rates under paleoenvironmental conditions using RPANDA. We further compared diversification rates between arid‐adapted lineages versus mesic‐adapted lineages using ClaDS and GeoHiSSE.ResultsAncestral area estimation indicated Australian blindsnakes have tropical grassland origins. We found that Australia‐specific regional paleotemperature and paleoaridity provided a better explanation for diversification rate variation than global paleotemperature. Specifically, our best‐fitting model indicated that speciation rates of blindsnakes decreased with increasing aridity. We found no difference in diversification rates between arid‐ and mesic‐adapted lineages.Main ConclusionsSoon after dispersing to Australia, the common ancestors of Australian blindsnakes diversified rapidly in mesic habitats during the early Miocene. However, as the continent became increasingly arid, diversification rates decreased. We found that shifts in the environment led to the emergence of two major clades: one remaining in primarily mesic habitats and the other adapting to the expanding arid biome. Our results emphasise the importance of both arid and tropical biomes as sources and sinks of diversification.

Dormancy in seeds of brazilian cerrado and dense Ombrophilous forest

The Cerrado and the Dense Ombrophilous Forest are important brazilian biomes that together cover more than half of the country's territory. They have a vast and rich plant diversity which often has a block in the germination process called dormancy. Dormancy can be defined as an obstruction in the germination of viable and intact seeds, even when all the favorable conditions are present. This work aimed to verify, through a literature survey, the occurrence of dormancy in seeds of plant species of the Brazilian Cerrado and Dense Ombrophilous Forest, comparing its occurrence between ecological groups of species, biomes and types of dormancy. The results showed that in Cerrado dormancy was observed in 56% of the species, whereas in Dense Ombrophilous Forest this number reduces to 42%. These data revealed an association between the presence of dormancy and the Cerrado. Also, in this biome, it was possible to verify a higher occurrence of physical dormancy in the seeds, with up to 63% of its dormant species presenting this type of dormancy. Pioneer species of Cerrado exhibited a greater dormancy percentage when comparing to climax, while this fact was not noticed in the forest, which resulted in an association between the ecological group of pioneer species from Cerrado and the dormancy process. These results show that dormancy may be related to more arid biomes and physical dormancy appears to be the most common type in these environments. Moreover, dormancy seems to be correlated with pioneer species of Cerrado, but not Forest

Dormancy in seeds of brazilian cerrado and dense Ombrophilous forest

The Cerrado and the Dense Ombrophilous Forest are important brazilian biomes that together cover more than half of the country's territory. They have a vast and rich plant diversity which often has a block in the germination process called dormancy. Dormancy can be defined as an obstruction in the germination of viable and intact seeds, even when all the favorable conditions are present. This work aimed to verify, through a literature survey, the occurrence of dormancy in seeds of plant species of the Brazilian Cerrado and Dense Ombrophilous Forest, comparing its occurrence between ecological groups of species, biomes and types of dormancy. The results showed that in Cerrado dormancy was observed in 56% of the species, whereas in Dense Ombrophilous Forest this number reduces to 42%. These data revealed an association between the presence of dormancy and the Cerrado. Also, in this biome, it was possible to verify a higher occurrence of physical dormancy in the seeds, with up to 63% of its dormant species presenting this type of dormancy. Pioneer species of Cerrado exhibited a greater dormancy percentage when comparing to climax, while this fact was not noticed in the forest, which resulted in an association between the ecological group of pioneer species from Cerrado and the dormancy process. These results show that dormancy may be related to more arid biomes and physical dormancy appears to be the most common type in these environments. Moreover, dormancy seems to be correlated with pioneer species of Cerrado, but not Forest

Accounting for fuel in fire danger forecasts: the fire occurrence probability index (FOPI)

A new fire danger index is proposed to overcome one of the most important limitations of current fire danger metrics. The fire occurrence probability index (FOPI) combines the Canadian fire weather index (FWI) with remote observations of vegetation characteristics to better predict landscape flammability. The FOPI is designed to improve fire danger predictions in all fuel-limited environments where fire is driven by the short-term drying of intermittently-available fuel. The FOPI considerably outperforms the FWI in arid biomes while remaining comparable to the FWI where fuel is abundant.

Net diversification rates of the woody plant genus Petalidium (Acanthaceae) are highest in the ancient and arid Namib Desert

At present, tropical arid biomes house less woody plant species diversity than tropical moist biomes, which could be due to lower rates of evolutionary diversification in the recent or distant past. Here, we study the evolutionary diversification of Petalidium (Acanthaceae), a genus of 36 species of woody shrubs found in the Namib Desert of southwest Africa, and surrounding areas. We generated a new, nearly fully sampled and temporally calibrated phylogeny for Petalidium using RADseq SNP data and secondary calibrations. We then investigated variation in net diversification rate across the phylogeny, the ancestral climatic niche of lineages and the link between the two. We find that arid climatic conditions are linked with increased rates of net species diversification in the genus. Despite its great age, the Namib Desert clearly hosts young plant radiations. This apparent contradiction can be explained by a scenario of high evolutionary turnover, in this case potentially caused by alternating hyper-arid and relatively mesic phases. Hyper-arid phases could result in high plant mortality and extinction of species, leading to ecological opportunity and diversification during mesic phases. Taken together, our results contribute to a growing body of literature that shows evidence for elevated rates of plant diversification in the Quaternary in arid biomes across the globe.

Contribution of soil bacteria to the atmosphere across biomes

The dispersion of microorganisms through the atmosphere is a continual and essential process that underpins biogeography and ecosystem development and function. Despite the ubiquity of atmospheric microorganisms globally, specific knowledge of the determinants of atmospheric microbial diversity at any given location remains unresolved. Here we describe bacterial diversity in the atmospheric boundary layer and underlying soil at twelve globally distributed locations encompassing all major biomes, and characterise the contribution of local and distant soils to the observed atmospheric community. Across biomes the diversity of bacteria in the atmosphere was negatively correlated with mean annual precipitation but positively correlated to mean annual temperature. We identified distinct non-randomly assembled atmosphere and soil communities from each location, and some broad trends persisted across biomes including the enrichment of desiccation and UV tolerant taxa in the atmospheric community. Source tracking revealed that local soils were more influential than distant soil sources in determining observed diversity in the atmosphere, with more emissive semi-arid and arid biomes contributing most to signatures from distant soil. Our findings highlight complexities in the atmospheric microbiota that are relevant to understanding regional and global ecosystem connectivity.

Feeding Ecology of the Cuvier’s Gazelle (Gazella cuvieri, Ogilby, 1841) in the Sahara Desert

Knowledge of the feeding ecology of ungulates in arid biomes offers an interesting model for understanding the drought resistance of large desert-adapted herbivores, a crucial issue in the face of increasing desertification due to climate change. To assess the feeding ecology of the endangered Cuvier's gazelle (Gazella cuvieri) in the Sahara desert, we used a multi-method approach combining faecal samples, direct observations, and the recording of indirect signs of feeding. We hypothesised that browser behaviour is the best foraging strategy for species living in hyper-arid environments, mainly due to long periods without grazing opportunities. Complementarily, we explored the effects of the main environmental descriptors (rainfalls and NDVI) on feeding patterns and diet quality. We found that Cuvier's diets are based mainly on acacias (Vachellia tortilis, V. flava) and occasionally on the annual forb Anastatica hierochuntica. In total, eighteen species (five trees, nine shrubs, three herbs, and one grass) belonging to fifteen families were recorded. Our result confirmed the browsers' characteristic of this species, reaffirming its ability to settle in a hostile environment. Acacias stand out as key species consumed at the southernmost limit of their range; hence, future conservation plans and strategies should take this into account for the survival of Cuvier's gazelle in desert environments.

Following the aridity: Historical biogeography and diversification of the Philodromidae spider genus Petrichus in South America

Aridity conditions and expansion of arid biomes in South America are closely linked to the onset of Andean orogeny since at least 30 Mya. Among arid-associated taxa, spiders belonging to the genus Petrichus are found along the Andes mountains and across the diagonal of open formations of the Chaco and Cerrado domains. In this contribution, we asked whether Petrichus originated prior to the central Andean uplift and what historical processes have promoted their diversification. We time-calibrated the phylogenetic tree of Philodromidae and estimated the divergence times of Petrichus. Considering phylogenetic uncertainty, we assessed biogeographical hypotheses of the historical events associated with the diversification of these spiders in South America. Petrichus originated along the Pacific coastal deserts in the Central Andes during the Early Miocene. The species likely dispersed from the western to the eastern side of the Andes coincidently with the central Andean uplift. The diversification of these spiders is coeval with the expansion of open grassland formations during the Late Miocene and Early Pliocene. Multiple dispersal events occurred from the Monte desert to southern South America and eastward to Chaco between ∼ 8 and 2.5 Mya. The Andes might have played a role as a corridor favoring geographical range expansions and colonization of new environments. In addition, we also suggest that Philodromidae might have an Oligocene origin or earlier. Future analyses based on further evidence and larger taxon sampling should be carried out to corroborate our findings.

100 million years of turtle paleoniche dynamics enable the prediction of latitudinal range shifts in a warming world

Past responses to environmental change provide vital baseline data for estimating the potential resilience of extant taxa to future change. Here, we investigate the latitudinal range contraction that terrestrial and freshwater turtles (Testudinata) experienced from the Late Cretaceous to the Paleogene (100.5-23.03 mya) in response to major climatic changes. We apply ecological niche modeling (ENM) to reconstruct turtle niches, using ancient and modern distribution data, paleogeographic reconstructions, and the HadCM3L climate model to quantify their range shifts in the Cretaceous and late Eocene. We then use the insights provided by these models to infer their probable ecological responses to future climate scenarios at different representative concentration pathways (RCPs 4.5 and 8.5 for 2100), which project globally increased temperatures and spreading arid biomes at lower to mid-latitudes. We show that turtle ranges are predicted to expand poleward in the Northern Hemisphere, with decreased habitat suitability at lower latitudes, inverting a trend of latitudinal range contraction that has been prevalent since the Eocene. Trionychids and freshwater turtles can more easily track their niches than Testudinidae and other terrestrial groups. However, habitat destruction and fragmentation at higher latitudes will probably reduce the capability of turtles and tortoises to cope with future climate changes.

Discovery of the First Blattinopsids of the Genus Glaphyrophlebia Handlirsch, 1906 (Paoliida: Blattinopsidae) in the Upper Carboniferous of Southern France and Spain and Hypothesis on the Diversification of the Family

Glaphyrophlebia victoiriensis sp. nov. (Paoliida: Blattinopsidae) is the third Gzhelian representative of the genus and is described based on a beautiful forewing from the Var department in Southern France. Together with the description of another forewing fragment of a Glaphyrophlebia sp. from the Province of León in NW Spain, they improve our knowledge of fossil insects from French and Spanish upper Carboniferous deposits. The specimen of Glaphyrophlebia sp. is the first mention of the family in the Carboniferous of Spain and extends the geographical distribution of the genus. These descriptions suggest that the genus Glaphyrophlebia was speciose during the Upper Pennsylvanian, while otherwise very diverse in the lower and middle Permian strata of the Russian Federation. We proposed the first hypothesis to explain the diversification of the family and of its most speciose genera and to argue that their diversity dynamics were likely linked with the major environmental changes that followed the collapse of the Carboniferous rainforest, notably the extension of arid biomes during the Permian period. The exquisite preservation and the fineness of the sediment from Tante Victoire, in which the new species was found, suggests that the locality is suitable for preserving other fossil insects and will require additional investigations.

The Hercules pseudoscorpions from Madagascar: A systematic study of Feaellidae (Pseudoscorpiones: Feaelloidea) highlights regional endemism and diversity in one of the “hottest” biodiversity hotspots

Madagascar is amongst the “hottest” biodiversity hotspots with extreme levels of diversity and endemism. Throughout the last decades, there has been substantial progress in documenting the Malagasy invertebrate fauna but no study has ever focused on pseudoscorpions (Arachnida: Pseudoscorpiones) in the arachnid fauna. Here we review the Malagasy fauna of Hercules pseudoscorpions (family Feaellidae), which are common in soil habitats of arid biomes across Madagascar. Using morphology and molecular data, we recover three reciprocally monophyletic clades that correspond to three new genera in well-defined biogeographical regions and identify twelve new species: Antsiarananaellagen. nov. for Antsirananaella lorenzorumsp. nov., Antsiarananaella leniaesp. nov., Antsiarananaella faulstichisp. nov. and Antsiarananaella marlaesp. nov.; Mahajanganellagen. nov. for Mahajanganella fridakahloaesp. nov., Mahajanganella heraclissp. nov. and Mahajanganella schwarzeneggerisp. nov.; Toliaranellagen. nov. for Toliaranella fisherisp. nov., Toliaranella griswoldisp. nov., Toliaranella mahnertisp. nov., Toliaranella meridionalissp. nov. and Toliaranella pumilasp. nov. Local endemism in this fauna is high and most species have small distributions, ranging from 20 km to 350 km linearly. Genetic distances between populations are also high, suggesting restricted dispersal or selection against dispersal in this fauna. Species’ ranges seem to be delimited by geological barriers including volcanic fields (Ambre-Bobaomby in the north of Madagascar), mountain ranges (foothills of the Central Highland Plateau), and rivers (Manankolana, Mandrare, Manombo and Onilahy Rivers and their anabranches), but mainly by different biome habitats. Overall, Madagascar emerges as a global “hotspot” of feaellid radiation and these animals may be used in future studies to test biogeographical hypotheses across xeric biomes on this island.