Terrestrial Taxa Research Articles

Trait-based prediction of extinction risk across terrestrial taxa

Species differ in their biological susceptibility to extinction, but the set of traits determining susceptibility varies across taxa. It is yet unclear which patterns are common to all taxa, and which are taxon-specific, with consequences to conservation practice. In this study we analysed the generality of trait-based prediction of extinction risk across terrestrial (including freshwater) vertebrates, invertebrates and plants at a global scale. For each group, we selected five representative taxa and within each group we explored whether risk can be related to any of 10 potential predictors. We then synthesized outcomes across taxa using a meta-analytic approach. High habitat specificity was a consistent predictor across vertebrates, invertebrates and plants, being a universal predictor of risk. Slow life-history traits – large relative offspring size, low fecundity, long generation length –, and narrow altitudinal range were also found to be good predictors across most taxa, but their universality needs to be supported with additional data. Poor dispersal ability was a common predictor of extinction risk among invertebrate and plant taxa, but not consistently among vertebrates. The remaining traits (body size, microhabitat verticality, trophic level, and diet breadth) were useful to predict extinction risk but only at lower taxonomical levels. Our study shows that despite the idiosyncrasies among taxa, universal susceptibility to extinction exists and several traits might influence extinction risk for most taxa. Informing conservation prioritization at lower taxonomic scales should however include taxon-specific trait-based predictors of extinction risk.

Observation of juvenile Eastern Blue Groper (Achoerodus viridis) on remnant oyster reefs in New South Wales, Australia.

Observation of juvenile Eastern Blue Groper (Achoerodus viridis) on remnant oyster reefs in New South Wales, Australia.

Community diversity of soil meso-fauna indicates the impacts of oil exploitation on wetlands

Soil meso-fauna can indicate ecological health and provide biotic metrics for evaluating ecosystem damage and environmental changes. However, the roles of the soil meso-fauna in wetlands affected by oil exploitation have rarely been studied. This study investigated the community of the soil meso-fauna and the soil environmental quality in the oil exploitation area (oil well area, transitional area, and natural area) of the Momoge wetland, China. The results revealed that the oil pollutants (polycyclic aromatic hydrocarbons, PAHs) in the oil exploitation area mainly contained 2–3 rings soil PAHs. Oil exploitation mainly affected the soil meso-faunal community by changing the soil environment and vegetation characteristics. The abundance and richness of the soil meso-fauna were negatively affected by oil exploitation, and the richness responded more sensitively than the abundance. The diversity and taxa composition of the soil meso-fauna can be used to indicate the impacts of oil exploitation on wetland ecosystems and assess the ecological health of wetlands. The terrestrial taxa of the soil meso-fauna in wetlands (Coccoidea, Carabidae larvae, Hydrophilidae larvae, and Aphididae) could tolerate the oil pollutants and intense exploitation disturbance, indicating a highly disturbed wetland ecosystem. The aquatic (Chironomidae) and terrestrial taxon (Tenebrionoidea) indicated an intermediately disturbed wetland ecosystem. The aquatic (Enchytraeidae and Tabanidae) and non-aquatic taxa (Lposcelididae, Oecobiidae, and Tenthredinidae) indicated an undisturbed natural wetland ecosystem. The results of this study provide promising opportunities for oil production management and conservation efforts for wetland resources and biodiversity.

Climate, immigration and speciation shape terrestrial and aquatic biodiversity in the European Alps

Quaternary climate fluctuations can affect speciation in regional biodiversity assembly in two non-mutually exclusive ways: a glacial species pump, where isolation in glacial refugia accelerates allopatric speciation, and adaptive radiation in underused adaptive zones during ice-free periods. We detected biogeographic and genetic signatures associated with both mechanisms in the assembly of the biota of the European Alps. Age distributions of endemic and widespread species within aquatic and terrestrial taxa (amphipods, fishes, amphibians, butterflies and flowering plants) revealed that endemic fish evolved only in lakes, are highly sympatric, and mainly of Holocene age, consistent with adaptive radiation. Endemic amphipods are ancient, suggesting preglacial radiation with limited range expansion and local Pleistocene survival, perhaps facilitated by a groundwater-dwelling lifestyle. Terrestrial endemics are mostly of Pleistocene age and are thus more consistent with the glacial species pump. The lack of evidence for Holocene adaptive radiation in the terrestrial biome is consistent with faster recolonization through range expansion of these taxa after glacial retreats. More stable and less seasonal ecological conditions in lakes during the Holocene may also have contributed to Holocene speciation in lakes. The high proportion of young, endemic species makes the Alpine biota vulnerable to climate change, but the mechanisms and consequences of species loss will likely differ between biomes because of their distinct evolutionary histories.

A sampling, exposure and receptor framework for identifying factors that modulate behavioural responses to disturbance in cetaceans.

The assessment of behavioural disturbance in cetacean species (e.g. resulting from exposure to anthropogenic sources such as military sonar, seismic surveys, or pile driving) is important for effective conservation and management. Disturbance effects can be informed by Behavioural Response Studies (BRSs), involving either controlled exposure experiments (CEEs) where noise exposure conditions are presented deliberately to meet experimental objectives or in opportunistic contexts where ongoing activities are monitored in a strategic manner. In either context, animal-borne sensors or in situ observations can provide information on individual exposure and disturbance responses. The past 15 years of research have greatly expanded our understanding of behavioural responses to noise, including hundreds of experiments in nearly a dozen cetacean species. Many papers note limited sample sizes, required knowledge of baseline behaviour prior to exposure and the importance of contextual factors modulating behavioural responses, all of which in combination can lead to sampling biases, even for well-designed research programs. It is critical to understand these biases to robustly identify responses. This ensures outcomes of BRSs help inform predictions of how anthropogenic disturbance impacts individuals and populations. Our approach leverages concepts from the animal behaviour literature focused on helping to avoid sampling bias by considering what shapes an animal's response. These factors include social, experience, genetic and natural changes in responsiveness. We developed and applied a modified version of this framework to synthesise current knowledge on cetacean response in the context of effects observed across marine and terrestrial taxa. This new 'Sampling, Exposure, Receptor' framework (SERF) identifies 43 modulating factors, highlights potential biases, and assesses how these vary across selected focal species. In contrast to studies that identified variation in 'Exposure' factors as a key concern, our analysis indicated that factors relating to 'Sampling' (e.g. deploying tags on less evasive individuals, which biases selection of subjects), and 'Receptor' (e.g. health status or coping style) have the greatest potential for weakening the desired broad representativeness of BRSs. Our assessment also highlights how potential biases could be addressed with existing datasets or future developments.

How much we know about Brazilian subterranean aquatic fauna

The first study concerning Brazilian subterranean fauna was the description of the phreatobitic fish Phreatobius cistenarum Goeldi, 1905, followed by the stygobitic fish Pimelodella kronei (Miranda Ribeiro, 1907). After that, biospeleological studies mainly focused on terrestrial taxa description, and in 1972 the first stygobitic invertebrate, Aegla cavernicola Türkay, 1972 (Decapoda, Aeglidae), was described. Here, we provided an overview of the Brazilian subterranean aquatic fauna knowledge. To date, ca. 270 troglobitic species are described, of which 64 are aquatic (22 fishes; 42 invertebrates) and 13 have amphibian habits (all isopods). Considering aquatic species, 15 species were described between 1905 and 1999, 13 in the 2000s, 27 in the 2010s, and 9 in the 2020s. Furthermore, new stygobitic species were confirmed by experts but not published due to the deficit of trained specialists. Brazil has the second higher world diversity in stygobitic fishes, and data about habitat, biology, and ecology are available. Most of them are generalist carnivorous occurring in alluvial sediments, shallow base-level streams, flooded caves, lakes in the water table, upper vadose tributaries, or epikarst aquifers. Usually, they have small populations, but some species have large population sizes for the subterranean patterns. Some species have regression of the agonistic, cryptobiotic, and photophobic behaviors and regression of the circadian rhythms compared to their epigean relatives. Moreover, some species have morphological and behavioral intraspecific differences. Around 50 fish species have stygophilic populations, and some studies compared biological and morphological aspects of epigean and hypogean populations. There are available data about the habitat and natural history of the described stygobitic invertebrates, of which most are amphipods and planarians. Few phylogenetic relicts and epikarstic species were described. Usually, stygobites have restricted distribution in a micro-basin or are endemic within a unique cave and have small populations. Morphological and populational studies are available for few taxa (e.g., decapods and gastropods), as well as behavior studies. Community studies discuss species richness and distribution related to abiotic variables, lithology, and responses to disturbances; only a study is about epikarstic communities. For stygophilic species, there are mainly studies on distribution patterns and new records. Concerning amphibian species, five species were described in the 2010s and eight in the 2020s, with notes on their natural history and habitat. The main threats to the subterranean aquatic fauna are pollution by pesticides, decreasing aquifer levels due to deforestation and water exploitation for irrigation, headwaters of rivers outside protected areas, suppression of habitats by mining and hydroelectrical activities, allied to the current dismantling and attacks to the Brazilian environmental policies. To date, 46 stygobites (16 fishes and 30 invertebrates) and five troglobitic amphibians are on the Brazilian Red List.

Structural and functional development of twelve newly established floodplain pond mesocosms.

Ecosystems are complex structures with interacting abiotic and biotic processes evolving with ongoing succession. However, limited knowledge exists on the very initial phase of ecosystem development and colonization. Here, we report results of a comprehensive ecosystem development monitoring for twelve floodplain pond mesocosms (FPM; 23.5 m × 7.5 m × 1.5 m each) located in south‐western Germany. In total, 20 abiotic and biotic parameters, including structural and functional variables, were monitored for 21 months after establishment of the FPMs. The results showed evolving ecosystem development and primary succession in all FPMs, with fluctuating abiotic conditions over time. Principal component analyses and redundancy analyses revealed season and succession time (i.e., time since ecosystem establishment) to be significant drivers of changes in environmental conditions. Initial colonization of both aquatic (i.e., water bodies) and terrestrial (i.e., riparian land areas) parts of the pond ecosystems occurred within the first month, with subsequent season‐specific increases in richness and abundance for aquatic and terrestrial taxa over the entire study period. Abiotic environmental conditions and aquatic and terrestrial communities showed increasing interpond variations over time, that is, increasing heterogeneity among the FPMs due to natural environmental divergence. However, both functional variables assessed (i.e., aquatic and terrestrial litter decomposition) showed opposite patterns as litter decomposition rates slightly decreased over time and interpond differences converged with successional ecosystem developments. Overall, our results provide rare insights into the abiotic and biotic conditions and processes during the initial stages of freshwater ecosystem formation, as well as into structural and functional developments of the aquatic and terrestrial environment of newly established pond ecosystems.

The Miocene wetland of western Amazonia and its role in Neotropical biogeography

AbstractIn the Miocene (23–5 Ma), a large wetland known as the Pebas System characterized western Amazonia. During the Middle Miocene Climatic Optimum (c. 17–15 Ma), this system reached its maximum extent and was episodically connected to the Caribbean Sea, while receiving sediment input from the Andes in the west, and the craton (continental core) in the east. Towards the late Miocene (c. 10 Ma) the wetland transitioned into a fluvial-dominated system. In biogeographic models, the Pebas System is often considered in two contexts: one describing the system as a cradle of speciation for aquatic or semi-aquatic taxa such as reptiles, molluscs and ostracods, and the other describing the system as a barrier for dispersal and gene flow for amphibians and terrestrial taxa such as plants, insects and mammals. Here we highlight a third scenario in which the Pebas System is a permeable biogeographical system. This model is inspired by the geological record of the mid-Miocene wetland, which indicates that sediment deposition was cyclic and controlled by orbital forcing and sea-level change, with environmental conditions repeatedly altered. This dynamic landscape favoured biotic exchange at the interface of (1) aquatic and terrestrial, (2) brackish and freshwater and (3) eutrophic to oligotrophic conditions. In addition, the intermittent connections between western Amazonia and the Caribbean Sea, the Andes and eastern Amazonia favoured two-way migrations. Therefore, biotic exchange and adaptation was probably the norm, not the exception, in the Pebas System. The myriad of environmental conditions contributed to the Miocene Amazonian wetland system being one of the most species-rich systems in geological history.

Strong and lasting impacts of past global warming on baleen whales and their prey.

Global warming is affecting the population dynamics and trophic interactions across a wide range of ecosystems and habitats. Translating these real‐time effects into their long‐term consequences remains a challenge. The rapid and extreme warming period that occurred after the Last Glacial Maximum (LGM) during the Pleistocene–Holocene transition (7–12 thousand years ago) provides an opportunity to gain insights into the long‐term responses of natural populations to periods with global warming. The effects of this post‐LGM warming period have been assessed in many terrestrial taxa, whereas insights into the impacts of rapid global warming on marine taxa remain limited, especially for megafauna. In order to understand how large‐scale climate fluctuations during the post‐LGM affected baleen whales and their prey, we conducted an extensive, large‐scale analysis of the long‐term effects of the post‐LGM warming on abundance and inter‐ocean connectivity in eight baleen whale and seven prey (fish and invertebrates) species across the Southern and the North Atlantic Ocean; two ocean basins that differ in key oceanographic features. The analysis was based upon 7032 mitochondrial DNA sequences as well as genome‐wide DNA sequence variation in 100 individuals. The estimated temporal changes in genetic diversity during the last 30,000 years indicated that most baleen whale populations underwent post‐LGM expansions in both ocean basins. The increase in baleen whale abundance during the Holocene was associated with simultaneous changes in their prey and climate. Highly correlated, synchronized and exponential increases in abundance in both baleen whales and their prey in the Southern Ocean were indicative of a dramatic increase in ocean productivity. In contrast, the demographic fluctuations observed in baleen whales and their prey in the North Atlantic Ocean were subtle, varying across taxa and time. Perhaps most important was the observation that the ocean‐wide expansions and decreases in abundance that were initiated by the post‐LGM global warming, continued for millennia after global temperatures stabilized, reflecting persistent, long‐lasting impacts of global warming on marine fauna.

Introduced mangroves escape damage from marine and terrestrial enemies.

The enemy release hypothesis (ERH) posits that introduced species often leave their enemies behind when introduced to a new range. This release from enemies may allow introduced species to achieve higher growth and reproduction and may explain why some invaders flourish in new locations. Red mangroves (Rhizophora mangle) were introduced to Hawai'i from Florida over a century ago. Because Hawai'i has no native mangroves, the arrival of R. mangle fundamentally changed the structure and function of estuarine shorelines. While numerous enemies affect red mangroves in their native range (tropical America), in Hawai'i, mangroves apparently experience little herbivory, which may explain why introduced mangroves are so productive, fecund, and continue to spread. In this study, we compared the effects of enemies in native and introduced populations of brackish red mangroves (R. mangle) in 8-10 sites in the native range (Florida, Belize, and Panama) and introduced range of mangroves (Hawai'i). At each site, we measured the (1) occurrence of enemies using timed visual surveys, (2) occurrence of damage to different mangrove structures (leaves, apical buds, dead twigs, roots, propagules, and seedlings), and (3) rate of propagule herbivory using tethering experiments. Consistent with the ERH, we found an order of magnitude less damage and fewer enemies in introduced than native mangrove sites. While introduced mangroves harbored few enemies and minimal damage, native mangroves were affected by numerous enemies, including leaf-eating crabs, specialist bud moths, wood-boring insects and isopods, and propagule predators. These patterns were consistent across all plant structures (roots to leaves), among marine and terrestrial enemies, and across functional groups (browsers, borers, pathogens, etc.), which demonstrates enemy escape occurs consistently among different functional groups and via trophic (e.g., herbivores) and non-trophic (e.g., root borers) interactions. Our study is among the first biogeographical enemy release studies to take a comprehensive approach to quantifying the occurrence of damage from a broad suite of marine and terrestrial taxa across an array of wetland plant structures. Understanding how natural enemies alter this key foundation species will become increasingly relevant globally as mangroves continue to invade new regions through intentional plantings or range expansion driven by climate change.

Egg size is a good predictor of parental care behaviour among bony fishes

AbstractParental care is a major feature in the evolution of life‐history traits and appears highly associated with the trade‐off between egg number and size. It has been a controversial issue in studies about reproductive strategy and is deemed to have evolved multiple times, both in aquatic and terrestrial taxa. To explore relationships between parental care and egg size, we examined 313 species of bony fishes, including 152 species with parental care and 161 species without parental care. We mapped parental care onto a maximum likelihood (ML) unrooted phylogeny and analysed egg size and numbers data set using a logistic regression. The phylogenetically controlled analyses revealed that parental care is dispersed along with the retrieved phylogeny and that at least four distinct lineages parallel evolved from non‐parental care lineages to parental care ones. The results of the logistic regression highlighted that egg size can be used as a good predictor of parental care and that there is a strong and consistent threshold in egg size transition between parental and non‐parental care fishes. We conclude that egg size predicts parental care in bony fish and that egg size distribution is polymodal within parental care species probably reflecting the variation in the amount of energy used for care. To advance the knowledge about the hypotheses raised in this study, it would be important to gather information about more species and their respective number and size of eggs and the presence/absence of parental care.

The neuroanatomy of Zulmasuchus querejazus (Crocodylomorpha, Sebecidae) and its implications for the paleoecology of sebecosuchians.

The endocranial structures of the sebecid crocodylomorph Zulmasuchus querejazus (MHNC 6672) from the Lower Paleocene of Bolivia are described in this article. Using computed tomography scanning, the cranial endocast, associated nerves and arteries, endosseous labyrinths, and cranial pneumatization are reconstructed and compared with those of extant and fossil crocodylomorphs, representative of different ecomorphological adaptations. Z. querejazus exhibits an unusual flexure of the brain, pericerebral spines, semicircular canals with a narrow diameter, as well as enlarged pharyngotympanic sinuses. First, those structures allow to estimate the alert head posture and hearing capabilities of Zulmasuchus. Then, functional comparisons are proposed between this purportedly terrestrial taxon, semi-aquatic, and aquatic forms (extant crocodylians, thalattosuchians, and dyrosaurids). The narrow diameter of the semicircular canals but expanded morphology of the endosseous labyrinths and the enlarged pneumatization of the skull compared to other forms indeed tend to indicate a terrestrial lifestyle for Zulmasuchus. Our results highlight the need to gather new data, especially from altirostral forms in order to further our understanding of the evolution of endocranial structures in crocodylomorphs with different ecomorphological adaptations.

Distal Humeral Morphology Indicates Locomotory Divergence in Extinct Giant Kangaroos

Previous studies of the morphology of the humerus in kangaroos showed that the shape of the proximal humerus could distinguish between arboreal and terrestrial taxa among living mammals, and that the extinct “giant” kangaroos (members of the extinct subfamily Sthenurinae and the extinct macropodine genus Protemnodon) had divergent humeral anatomies from extant kangaroos. Here, we use 2D geometric morphometrics to capture the shape of the distal humerus in a range of extant and extinct marsupials and obtain similar results: sthenurines have humeral morphologies more similar to arboreal mammals, while large Protemnodon species (P. brehus and P. anak) have humeral morphologies more similar to terrestrial quadrupedal mammals. Our results provide further evidence for prior hypotheses: that sthenurines did not employ a locomotor mode that involved loading the forelimbs (likely employing bipedal striding as an alternative to quadrupedal or pentapedal locomotion at slow gaits), and that large Protemnodon species were more reliant on quadrupedal locomotion than their extant relatives. This greater diversity of locomotor modes among large Pleistocene kangaroos echoes studies that show a greater diversity in other aspects of ecology, such as diet and habitat occupancy.

Genomewide analysis of sperm whale E2 ubiquitin conjugating enzyme genes

Marine mammals are exposed to the oxidative stress induced by hypoxia/reoxygenation cycles yet resist cellular damage. The availability of high-quality genomes promises to provide insights on how this is achieved. In this study, we considered the ubiquitinconjugating enzymes (E2) gene family, UBE2 genes, which encodes enzymes with critical roles in cellular physiology, including the oxidative stress response. The sperm whale was the first marine mammal with a chromosome-level genome, allowing the study of gene family repertories, phylogenetic relationships, chromosome gene organization, and other evolutionary patterns on a genomewide basis. Here, 39 UBE2 genes (similar to human, including 32 intact genes, one partial gene, six pseudogenes) were identified in sperm whale genome. These genes were found on 17 chromosomes and were assigned into 23 subfamilies, 16 subgroups, and four classes based on structural characteristics and functions, phylogeny and conserved domains, respectively. Although the gene structure and motif distribution of sperm whale UBE2 genes are conserved in each subfamily, motif variation and intron gain/loss may contribute to functional divergence. Segmental duplications were detected in six gene pairs, which could drive UBE2 gene innovation in the sperm whale. Contrasting seven cetaceans and five terrestrial taxa, we found that cetaceans have experienced shifts in selective constraint on UBE2 genes, which may contribute to oxidative stress tolerance during the adaptation to aquatic life. Our results provide the first comprehensive survey of cetacean UBE2 genes.

Integrative analyses ofCrepidium(Orchidaceae, Epidendroideae, Malaxideae) shed more light on its relationships withDienia,LiparisandMalaxisand justify reinstatement of narrow endemicC. allanii

AbstractMalaxidinae are a cosmopolitan higher Epidendroid subtribe of > 1250 species that exhibit wide morphological and ecological diversity. Despite almost two centuries of taxonomic deliberation, controversy persists regarding the delimitation of practically all Malaxidinae genera, the most important of which are Crepidium, Dienia, Liparis and Malaxis. Previous attempts to classify these genera using a molecular phylogenetic approach showed Liparis and Malaxis to be polyphyletic and the floral characters traditionally used to define them as homoplastic. Emphasis has instead shifted to vegetative and ecological traits. Here, we conduct an expanded analysis of nuclear (ITS) and plastid (matK) sequences focused on terrestrial taxa, with the resulting phylogram largely corroborating the emerging picture, and we test the efficacy of four previously highlighted traits to recover the same relationships. Although growth habit is underscored as important for resolving a natural distinction between epiphytic Liparis and terrestrial ‘Crepidium clade’ plus ‘Malaxis clade’ taxa, leaf shape and venation and habitat preference are shown to be poor predictors of phylogenetic affiliation. Instead, perennating organ structure (heteroblastic or homoblastic) and placement (predominantly above- or below-ground) – are incisive, with leaf number and texture apparently correlated. These findings are discussed in the context of an inferred evolutionary history of the subtribe. Although homoplastic at the subtribe level, some floral characters are shown to be useful for resolving identities at the species level. Accordingly, the status of four long-confused species (Crepidium acuminatum, C. allanii, C. purpureum and Microstylis biloba) is resolved.

Neither historical climate nor contemporary range fully explain the extant patterns of molecular diversity in marine species

AbstractAimIntraspecific diversity is a significant component of adaptive potential, and thus, it is important to identify the evolutionary processes that have and will continue to shape the molecular diversity of natural populations. This study aims to untangle the possible drivers of intraspecific molecular diversity by testing whether patterns of historical climatic stability or contemporary range position correlate with molecular diversity.LocationSouth African coastline.TaxaThe cape urchin (Parechinus angulosus), common shore crab (Cyclograpsus punctatus) and granular limpet (Scutellastra granularis).MethodsSpecies distributions were hindcasted to the Last Glacial Maximum to assess the biogeography of the study species. Linear models were built to compare the relationships between historical climatic stability or contemporary distributional ranges with extant genetic (mtDNA) and genomic (SNP) diversity.ResultsWe found large differences in the historical ranges among species and time periods. Regions of higher habitat stability corresponded to regions of higher molecular diversity, but historical climatic variability was not a predictor of molecular diversity within linear models. Lower genetic diversity values, and higher genetic differentiation, were detected in edge populations, but this was not consistent across marker type or species.Main conclusionsBoth historical and contemporary processes are potentially driving patterns of diversity, but a large portion of the variation in molecular diversity remains unexplained. Our findings suggest that marine species within cool‐temperate bioregions in the Southern Hemisphere may have more complex biogeographic and evolutionary histories than terrestrial taxa and/or coastal species within northern, formerly glaciated regions.

Applying Biodiversity Metrics as Surrogates to a Habitat Conservation Plan

Unabated urbanization has led to environmental degradation and subsequent biodiversity loss across the globe. As an outcome of unmitigated land use, multi-jurisdictional agencies have developed land use plans that attempt to protect threatened or endangered species across selected areas by which some trade-offs between harm to species and additional conservation approaches are allowed among the partnering organizations. Typical conservation plans can be created to focus on single or multiple species, and although they may protect a species or groups of species, they may not account for biodiversity or its protection across the given area. We applied an approach that clustered deductive habitat models for terrestrial vertebrates into metrics that serve as surrogates for biodiversity and relate to ecosystem services. In order to evaluate this process, we collaborated with the partnering agencies who are creating a Multi-Species Habitat Conservation Plan in southern California and compared it to the entire Mojave Desert Ecoregion. We focused on total terrestrial vertebrate species richness and taxon groupings representing amphibians, birds, mammals, and reptiles, and two special status species using the Normalized Index of Biodiversity (NIB). The conservation planning area had a lower NIB and was less species rich than the Mojave Desert Ecoregion, but the Mojave River riparian corridor had a higher NIB and was more species-rich, and while taxon analysis varied across the geographies, this pattern generally held. Additionally, we analyzed desert tortoise (Gopherus agassizii) and desert kit fox (Vulpes macrotis arsipus) as umbrella species and determined that both species are associated with increased NIB and large numbers of species for the conservation area. Our process provided the ability to incorporate value-added surrogate information into a formal land use planning process and used a metric, NIB, which allowed comparison of the various planning areas and geographic units. Although this process has been applied to Apple Valley, CA, and other geographies within the U.S., the approach has practical application for other global biodiversity initiatives.

Stable isotopes of a terrestrial amphibian illustrate fertilizer-related nitrogen enrichment of food webs in agricultural habitats

To comprehensively assess the impacts of agricultural practices on biodiversity in complex landscapes mixing both agricultural habitats and remnants of other (presumably more favorable) types of habitats, a prerequisite is to evaluate to which extent agricultural habitats are actually used by a given species. Here, we tested whether the stable isotope method can help to discriminate habitat use of a wild vertebrate, the spined toad (Bufo spinosus). We expected habitat to influence their δ13C values and the use of fertilizers to increase δ15N values of individuals from agricultural landscapes. Based on 114 toads from seven sites characterized by contrasted habitats (agricultural, forest or mixed habitats), we found that toad blood δ15N values were positively related to agricultural surface area, a result that was corroborated by diverging blood δ15N values between habitat categories. Conversely, toad δ13C values did not vary according to the habitat. Our results suggest that isotopic values (especially δ15N) could be a powerful tool to assess agricultural habitat use in terrestrial taxa. Further studies should usefully investigate whether individual δ15N values can be used as a fingerprint of other constraints of agricultural habitats (e.g., contaminants) in agricultural landscapes.

Local and downstream cumulative effects of traditional meadow management on stream-water quality and multiple riparian taxa

Water quality and riparian communities are among the most affected stream components by agriculture. However, little is known about the effects of riparian management for both aquatic and terrestrial taxa at different spatial scales. Here, we surveyed aquatic (diatoms) and terrestrial taxa (bryophytes, vascular plants, litter-dwelling snails, and ground and volant arthropods), to compare the abundance and richness of riparian taxa and chemical quality between reference and exposed sites in two stream reaches each of c. 3.5 km in northwestern Spain. Impacts in exposed sites were mainly due to traditional farming practices (TFPs), which included traditional meadow management, weirs built for now-unused water mills and sporadic timber harvesting. Therefore, we measured ten covariates and predictors related to the intensification of TFPs at local and within-stream scales and explored associations with riparian and water-quality measures to study the potential effects of TFPs in more detail. Reference and exposed sites did not differ significantly in water properties (diatom-biotic indices, conductivity, total organic carbon and nitrates), but exposed sites had less concentrations of soil metals Cd, Cu, Ni and Zn and less cover and richness of riparian trees, as inferred by the index QBR. Exposed sites had more volant insect decomposers and reference sites a greater abundance or richness of snails, ground predators and decomposers. Bryophyte richness was greater in reference sites. Our inferences may inform the joint cumulative downstream effects of weirs, meadow uses and riparian alterations but were generally consistent with most riparian taxa benefiting from having larger forested areas. Given the contrasting responses among taxa, we argue that land snails, terrestrial flies, and centipedes may be valuable additions to current riparian assessments mostly based on plants, beetles and spiders as indicator taxa. Our study also suggests caution when inferring farming impacts on streams from the surface area of pastoral land.

Non‐stationary drivers on fish sampling efforts in Brazilian freshwaters

AbstractAimClosing knowledge gaps in species taxonomy and distribution (i.e. Linnean and Wallacean shortfalls, respectively) require spatially distributed high‐quality data. However, studies on terrestrial taxa have shown that occurrence data are biased owing to higher sampling efforts towards areas with greater accessibility, research infrastructure and attractiveness. Here, we tested whether these biasing factors are also important drivers of freshwater fish species research by assessing fishes’ sampling efforts in Brazil, a continental‐sized and megadiverse country. We hypothesized that the influence of biasing factors is scale‐dependent, with differential effects across regions, that is that they present non‐stationarity.LocationBrazil.MethodsWe modelled sampling events of fish (gathered from online databases) as a function of accessibility (population density, distance from access routes and density of access routes), availability of research infrastructure (distance from research centres) and attractiveness of protected areas (distance from protected areas), by using a traditional stationary model (ordinary least square models—OLS) and a model taking into account non‐stationarity (geographically weighted regression—GWR).ResultsWe recorded 43,538 sampling events distributed across Brazil. Freshwater fish samplings were spatially biased with a tendency for major efforts to be concentrated in sites with a higher density of access routes, population and nearness to research centres and protected areas. However, GWR models performed better than the OLS model, revealing the non‐stationarity of the effects of predictors in explaining the number of sampling events.Main conclusionsOvercoming Linnean and Wallacean shortfalls for freshwater fish species in megadiverse regions such as Brazil can be aided by financially supporting the sampling efforts in less accessible and less populated sites farther from research centres and well‐studied protected areas. However, the source of biasing has strong scale dependency, so that reducing a specific source of bias is not expected to have the same effectiveness in all areas.