Low Dispersal Ability Research Articles

On the path to extinction: Helix godetiana Kobelt, 1878, the only threatened Helix species in Greece

Land snails and the Aegean Archipelago offer an intriguing combination for studying biodiversity, biogeography and ecology. A region with high environmental and temporal heterogeneity and a tri-continental biotic influence and a group of organisms with low active dispersal abilities, high endemism, as well as the particularity to leave shells as traces of past presence, set an ideal stage for testing biodiversity patterns and exploring multisource threats, especially in the era of the ongoing biodiversity crisis. In this study, we examine Helix godetiana, a large-sized, threatened and endemic land snail of the central and south Aegean Islands. The species has been extirpated from 22 of the 32 islands where it was historically present. We identify potential drivers of its extinction, as Helix godetiana faces several threats across its current range, including competitive exclusion by Cornu aspersum, a species with continuing expansion in the Aegean and climate change disrupting its unusual breeding cycle, which occurs in late spring. Our findings shed light on potentially major, yet previously unexplored, threats on endemic molluscs of the Aegean Islands, a European biodiversity hotspot.

Climate Change Effects on the Only Western Palearctic Plethodontids: Range Changes and Possible Depletion of Intraspecific Genetic Diversity

ABSTRACTAimAmphibians are particularly sensitive to rapid climatic shifts, due to their eco‐physiology, life history traits and high frequency of narrowly distributed species. The genus Speleomantes encompasses the only extant Western Palearctic plethodontids, with three species occurring in peninsular Italy and the remaining five endemic to Sardinia Island.Given the restricted ranges of Speleomantes species and their vulnerability to environmental change, we implemented Ecological Niche Models (ENMs) to estimate the likely impacts of various global warming scenarios on the extent and geographical location of climatically suitable areas.Time PeriodCurrent, with ENMs projected to 2030, 2050 and 2070 under alternative Shared Socioeconomic Pathways.LocationItalian Peninsula and Sardinia Island.Major Taxa StudiedSpeleomantes Dubois 1984 (Caudata: Plethodontidae).MethodsEnsembles of ENMs were fitted for each Speleomantes species, using the ‘biomod2’ modelling platform in R environment. Then, post‐modelling analyses were applied in GIS environment to highlight: (i) the primary geographic direction of predicted suitability shifts for each species and (ii) the proportion of stable, gained and lost suitable areas for each genetic lineage of the single species.ResultsWe found a noticeable shrinking of suitable areas for all Speleomantes species, being particularly extensive under ‘business‐as‐usual’ scenarios for the Sardinian ones. Moreover, core suitable areas were predicted to shift for most species and suitability losses emerged to differently affect distinct genetic lineages, posing additional challenges for designing effective conservation measures.Main ConclusionsThe predicted shrinkage and shifting of climatically suitable areas for most Speleomantes species point to the urgency of evaluating in due time alternative conservation strategies for these endemic urodeles, to prevent losses of taxonomic and genetic diversity. Our modelling framework may be applied to other species with similar traits (e.g., low dispersal ability and narrow environmental niche breadth) to predict climate‐induced range contractions or shifts, using the gained information to optimise conservation outcomes.

Temperature niche and body size condition phenological responses of moths to urbanization in a subtropical city.

Urbanization in temperate climates often advances the beginning and peak of biological events due to multiple factors, especially urban heat islands. However, the effect of urbanization on insect phenology remains understudied in more tropical areas, where temperature may be a weaker phenological cue. We surveyed moths across an urban gradient in a subtropical city weekly for a year to test how impervious surface and canopy cover impact phenology at the caterpillar and adult life stages. For macro-moths, we also examine how these effects vary with life history traits. When pooling all individuals, we found no effect of urbanization proxy variables on timing of caterpillar or adult phenology. At the species-specific level, we found timing of peak adult macro-moths is influenced by canopy cover, which also interacts with two traits: temperature niche and body size. Cold-adapted species delay timing of peak abundance in more shaded sites, while warm-adapted species were not affected. Smaller species, associated with lower dispersal ability, were more phenologically sensitive to canopy cover than larger bodied species. These results highlight the importance of canopy cover within cities and its interaction with species' traits in mediating impact of urbanization on moth phenology in subtropical systems.

Population genetics analysis based on mitochondrial cytochrome c oxidase subunit I (CO1) gene sequences of Cottus koreanus in South Korea.

The freshwater sculpin Cottus koreanus is endemic to the Korean Peninsula and has a fluvial life history. However, its population has been greatly reduced and it is now listed as an endangered class II species. To obtain important information for its conservation, we examine the genetic diversity, population structure, and demographic history of C. koreanus through mitochondrial cytochrome c oxidase subunit I (CO1) gene sequence analysis. We analyzed the CO1 gene sequences of 430 individuals of C. koreanus from 23 populations in South Korea. In all, 32 haplotypes were defined by 124 variable nucleotide sites, of which 28 were unique haplotypes not shared with other regional populations. All sampled populations had high haplotype diversity (Hd = 0.941) and low nucleotide diversity (π = 0.0146). Median-joining network analysis identified two divergent clusters: cluster I that had unique haplotype patterns assigned to each population and cluster II that had a star-like pattern. Each was supported by pairwise FST values and hierarchical analysis of molecular variance. The results of the mismatch distribution, goodness-of-fit test, and extended Bayesian skyline plot analysis showed that cluster I has experienced a gradual population expansion since the last glacial maximum, while cluster II experienced a sudden one. The results of neutrality testing supported the results for cluster II but the signal was weak. C. koreanus inhabits the upper reaches of rivers and has extremely low dispersal ability, resulting in unique genetic structure patterns among populations. Therefore, all populations should be managed and conserved separately.

Historical and ongoing hybridisation in Southern South American grassland species

Natural hybridisation in plants can impact genetic and morphological diversity, including the emergence of better-adapted new populations and the potential extinction of some lineages involved in this intricate process. Under progressive global warming, species often need to migrate to newly suitable areas, which may be an additional challenge for species with low dispersal ability. Throughout the search for new environments, previously allopatric lineages can come into secondary contact and eventually hybridise if reproductive isolation is incomplete. Here, we focused on two taxa representing the natural herbaceous component of southern South American lowland grasslands. We aimed to evaluate the impact of contact zones and potential hybridisation on the evolutionary relationships and population dynamics. We used single nucleotide polymorphisms and morphological data of multiple individuals from allopatric and contact zones between taxa to shed light on hybridisation patterns and demographic scenarios. Our results indicated that the contact zones impact taxa’s genetic and morphological diversity, and each contact zone had different patterns of genetic diversity and morphology, constituting stable populations that potentially reflect hybridisation events occurring at distinct evolutionary times.

A habitat is not enough - increasing the chances of success for species reintroduction in riverscapes by habitat modeling and connectivity analysis

Alpine rivers are among the most heavily modified ecosystems in Europe. Following massive interventions in the 18th and 19th centuries, many plant species specialized in these challenging environments declined and are now endangered or even locally extinct. Today, attempts are being made to reintroduce these species as part of restoration measures, but only a few are successful. The selection of potential sites for reintroduction is commonly intuitive and based on practical considerations, while a prior scientific assessment of habitat availability and habitat connectivity is lacking. To increase the success of future reintroductions, we employ a habitat suitability model and subsequent habitat connectivity analysis to identify promising regions and patches for reintroduction within a riverscape. We demonstrate this approach using the Alpine river specialists Chondrilla chondrilloides and Myricaria germanica in three differently degraded and one restored section of the large Alpine river Isar. All river sections provide habitats for both species, but with increasing degradation, habitats become fewer and less connected. For the species with a narrower habitat niche and lower dispersal ability, suitable and connected patches that support a self-sustained metapopulation are only found in the near-natural sections. Despite an improvement in the habitat situation, the patch size in the restored section is too small, and the patches are too scattered to support a successful reintroduction of the species. We show that this evidence-based approach outperforms an intuitive selection of out-planting sites. The results further underline the importance of using scientific habitat analysis to increase the success of reintroduction measures.

Diatom metacommunity structuring in a large lake: geomorphic, water chemistry and dispersal effects on diatom guilds in Lake Ladoga (north-western Russia)

The relative importance of environmental filtering and dispersal in structuring metacommunities of littoral periphytic diatoms was assessed within a large lake (Lake Ladoga, north-western Russia). We hypothesized that different diatom functional guilds (high-profile, low-profile, motile and planktic) would respond differently to environmental and spatial variables, depending on their mode of attachment and dispersal ability. Guilds showed distinct distributional patterns along a gradient of wave-induced disturbance: low-profile diatoms dominated in exposed shorelines (high disturbance), whereas high-profile and motile diatoms were more abundant in coastal wetlands (low disturbance). Redundancy analysis with variation partitioning of the entire diatom community revealed that environmental variables (littoral geomorphology and water chemistry) outperformed spatial variables, indicating a predominant role of species sorting. When the diatom community was deconstructed into functional groups, benthic guilds (i.e., low-profile, high-profile and motile) showed higher dependence on environmental factors, whereas the planktic guild was primarily predicted by spatial factors. Thus, benthic taxa with lower dispersal abilities were less impacted by mass effects than planktic taxa. Among benthic guilds, motile diatoms were less sensitive to water chemistry compared to low-profile and high-profile diatoms, suggesting that a group-specific habitat preference may interfere with diatom responses to water quality changes. Hence, the response of diatom guilds to water quality parameters was related to their resistance to wave action. Overall, we concluded that the higher importance of environmental filtering than dispersal-related processes in shaping the diatom metacommunity resulted from a combination of a strong environmental gradient in geomorphology/water chemistry and the intermediate spatial scale of our study.

Influence of habitat fragmentation and habitat amount on soil fungi communities in ancient forests

ContextFungi represent a large part of soil biodiversity as well as an essential role for tree hydromineral nutrition, survival, and carbon cycling. While their local diversity has proven to be shaped by abiotic and biotic factors related to soil, climate and vegetation, their response to landscape fragmentation is still debated.ObjectivesIn this paper, we focus on ancient forests characterized by the presence of beech at low elevation, a habitat particularly fragmented in South-West France. We aim to assess the effect of past and present forest fragmentation and quantity on soil fungal and functional group diversity. We expect a negative impact of fragmentation and a positive effect of forest quantity on soil fungal diversity, in addition to an influence of local soil factors.MethodsSoils from 41 1ha ancient forest plots across South-West France were sampled along gradients of past and present forest fragmentation and quantity, before their fungal diversity was characterized by metabarcoding of environmental DNA. Hill numbers have been computed and applied to all fungi, trophic guilds and growth forms.ResultsWe find that past forest fragmentation negatively impacts on soil fungal diversity and in particular for symbiotrophs, while the present forest quantity has a positive impact. In contrast, the species richness of pathotrophic fungi shows a negative correlation with past forest fragmentation. The diversity of fungal groups with lower dispersal abilities (e.g., corticioid, microfungi) is negatively impacted by past forest fragmentation, while the diversity of wind-dispersed fungi (e.g., agaricoid) is not influenced by any landscape descriptors.ConclusionsOur results show the complexity of fungal responses to past and present forest fragmentation and demonstrate the long-lasting effect of past fragmentation as well as the positive impact of recent forest quantity in the landscape on fungal diversity associated with ancient forest soils. Our study also highlights the huge diversity of fungi unraveled by eDNA metabarcoding in this habitat and the potential of such techniques to study the landscape ecology of soil communities.

Long‐term drought triggers severe declines in carabid beetles in a temperate forest

Evidence for widespread declines in arthropods is growing and climate change is one of the suspected drivers. Recent droughts in Europe were unprecedented in the previous centuries and we are only beginning to understand the impacts on ecosystems. We analysed a 24‐year dataset of carabid beetles from a temperate forest area in northeast Germany and investigated linear and non‐linear trends in carabid abundance, biomass, diversity and species traits. We were especially interested if and how these were linked to droughts at different temporal scales using the standardized precipitation evapotranspiration index (SPEI). We found significant linear declines in abundance and biomass with annual rates of −3.1% (0.95 CI [−5.3, −1]) and –4.9% (0.95 CI [−9.4, −1.6]), respectively. Non‐linear trends were closely related to the SPEI when considering the climatic water balance of the previous six years and showed severe declines between 2015 and 2022 (−71% abundance, 0.95 CI [−84, −61] / −89% biomass, 0.95 CI [−97, −59]). However, there remained a significant annual background‐decline of −2.1% (0.95 CI [−5.7, −0.2]) and −3.1% (0.95 CI [−6.5, −0.1]), respectively, which occurred independently of drought. We observed negative trends in standardized carabid diversity metrics and a shift in species assemblage that were less directly linked to droughts. Declining and drought‐sensitive species tended to be larger predators with low dispersal abilities. This study is among the very first to investigate the impacts of the current unprecedented drought on forest insects in central Europe. Our findings add to the concerning amount of evidence for widespread declines in arthropods while pointing towards weather anomalies and climate change as one important driver.

Climate and dispersal limitation drive tree species range shifts in post-glacial Europe: results from dynamic simulations

IntroductionThe ability of species to colonize newly suitable habitats under rapid climate change can be constrained by migration processes, resulting in a shift of the leading edge lagging behind the ameliorating climate, i.e. migration lag. The importance and extent of such migration lags during the forest expansion after the Last Glacial Maximum (LGM) are still debated. Similarly, the relative importance of the main drivers of post-glacial vegetation dynamics (temperature, dispersal limitation, and competition) is still discussed in the literature.MethodsWe used the dynamic global vegetation model LPJ-GM 2.0 to reconstruct the range shifts of 16 competing major European tree species after the LGM (18.5 ka BP) until recent times (0 ka BP). We simulated two dispersal modes by allowing free establishment whenever the climatic conditions suited the species (free dispersal), or by accounting for migration processes in the simulated vegetation dynamics (dispersal limitation). We then calculated thermal and range shift velocities, competition at establishment, thermal and dispersal lags for each species and dispersal mode. Finally, we compared our simulated range shift velocities with pollen-derived migration rates.ResultsThe simulation assuming limited dispersal resulted in more accurate migration rates as compared to pollen-derived migration rates and spreading patterns. We found no marked migration lags in the post-glacial establishment of pioneer species (Pinus sylvestris and Betula pubescens). Under the free dispersal mode, the remaining temperate species expanded rapidly and almost synchronously across central Europe upon climate warming (Bølling-Allerød interstadial). Differently, the northward spread of temperate species simulated under dispersal limitation happened mainly during the Holocene and in successive waves, with late spreaders (e.g. Fraxinus excelsior) experiencing multi-millennial dispersal lags and higher competition.DiscussionOur simulation under dispersal constraints suggests that the post-glacial tree expansion in Europe was mainly driven by species-specific thermal requirements and dispersal capacity, which in turn affected the order of taxa establishment and thus the degree of competition. Namely, taxa with less cold-tolerance and relatively low dispersal ability experienced the highest migration lags, whereas the establishment of pioneer species was mostly in equilibrium with the climate.

No impact of habitat fragmentation on condition and dispersal ability in the highly mobile butterfly Pieris rapae

AbstractThe loss and fragmentation of natural habitats due to agricultural intensification have a strong negative impact on farmland biodiversity. The concomitant isolation of essential resources may exert selection pressures toward increased dispersal performance in flying insects, possibly resulting in differences in flight morphology and dispersal propensity across landscapes. Here, we compared condition, flight morphology, dispersal capacity, and propensity of the common butterfly Pieris rapae among four pairs of highly fragmented “modern” and less fragmented “traditional” agricultural landscapes. We did not find differences between landscape types, but between locations and sexes. These results are not entirely unexpected, as P. rapae is a highly mobile generalist species, able to exploit temporarily available resources such as rapeseed in modern agricultural landscapes. In addition, our negative results may suggest a lack of time for evolutionary change such that differences may appear in the future. However, more specialized species with low dispersal ability may show clearer patterns and may well suffer from habitat fragmentation, and investigating such interrelation is an important task for future research.

Elevational Goldilocks zone underlies the exceptional diversity of a large lizard radiation (Liolaemus; Liolaemidae).

Mountains are among the most biodiverse regions on the planet, and how these landforms shape diversification through the interaction of biological traits and geo-climatic dynamics is integral to understanding global biodiversity. In this study, we investigate the dual roles of climate change and mountain uplift on the evolution of a hyper-diverse radiation, Liolaemus lizards, with a spatially explicit model of diversification using a reconstruction of uplift and paleotemperature in central and southern South America. The diversification model captures a hotspot for Liolaemus around 40°S in lineages with low-dispersal ability and narrow niche breadths. Under the model, speciation rates are highest in low latitudes (<35°S) and mid elevations (~1,000 m), while extinction rates are highest at higher latitudes (>35°S) and higher elevations (>2,000 m). Temperature change through the Cenozoic explained variation in speciation and extinction rates through time and across different elevational bands. Our results point to the conditions of mid elevations being optimal for diversification (i.e., Goldilocks Zone), driven by the combination of (1) a complex topography that facilitates speciation during periods of climatic change, and (2) a relatively moderate climate that enables the persistence of ectothermic lineages and buffers species from extinction.

A new species of Janiralata Menzies, 1951 (Isopoda: Janiridae) from Japanese bathyal waters, with a review of the associations with invertebrates among the species of Janiralata

Abstract Isopods of the genus Janiralata Menzies, 1951 (Asellota: Janiridae) are known from shallow and deep waters of the Northern Hemisphere. Most species are free-living, but some are symbiotic on the surface of other benthic invertebrates. We obtained from three beam- and four otter-trawl hauls 18 Janiralata asellote specimens from the bathyal zone off the Pacific coasts of Tohoku, northeastern Japan. Partial nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene (505 bp) were determined for 16 of the 18 collected specimens. Non-significant genetic differences (&amp;lt; 0.8%) indicated that the individuals were conspecifics. Morphological analysis indicated that all the specimens belonged to a single species, Janiralata planasp. nov. based on the unique morphology of the anterolateral and distolateral projections on the head and pleotelson, surface and lateral margins of the body, antennula article 1, and of the male pleopod 1. Six of the 18 collected specimens were found attached to the surface of an unidentified sea anemone (Hormathiidae), ten to the solasterid starfish Crossaster borealis Fisher, 1906 and two were obtained from the bottom sediment. Three COI haplotypes of the new species were shared by individuals from two neighboring sites, which suggests that genetic isolation occurs on a relatively narrow horizontal scale, although the bathymetric distribution range was rather wide. We describe a case study of the geographic and bathymetric distributions of an asellote species with low dispersal ability and its genetically differentiated populations. Such approach could help elucidate the diversity and distribution of deep-sea organisms and their diversification processes.

Predictions based on phylogeography and climatic niche modelling depict an uncertain future scenario for giant blister beetles (Berberomeloe, Meloidae) facing intensive greenhouse expansion and global warming

Abstract Large‐scale agricultural and tourism development are the main threats to biodiversity in south‐eastern Spain. Species with low dispersal abilities, such as some endemic insects from this region, are particularly vulnerable to fragmentation and loss of genetic and morphological diversity. Here, we studied the current and future threat of climate and land‐use change on the intraspecific diversity of one such group of endemics, the giant blister beetles of the Berberomeloe insignis species group. Using a phylogeographic approach and morphometrics, we identified intraspecific variation within the B. insignis species group. These data were coupled with ecological niche modelling (ENM) to determine the effect of agricultural and climate change on the connectivity across phylogroups. We identified a marked geographic structure within B. insignis, with the time to the most recent common ancestor (TMRCA) of the two main mtDNA clades dating back to 2.1 Ma. Cyto‐nuclear discordances found across parapatric populations suggest past events of genetic introgression. B. insignis presents a head pattern that is geographically structured and mostly congruent with the four mitochondrial lineages. In contrast, diversification within Berberomeloe tenebrosus is more recent, dating back to less than 1 Ma. Future ENMs highlight the role of mountains as potential refugia under a climate warming scenario but predict extinctions in the lowlands. Based on our analyses, two lineages of B. insignis are threatened and should be urgently considered as independent conservation units, and their current geographic distribution areas protected to conserve, at the very least, a portion of the species' evolutionary heritage.

Do carabids struggle to recolonize restored grasslands in the fragmented landscapes of Northern Belgium?

Abstract Semi‐natural grasslands in Western Europe are degrading and declining. Their plant species diversity and associated fauna, such as arthropods, are decreasing fast making restoration crucial. Carabid beetles are an essential link in ecosystem functioning (e.g., through herbivory and predation) and provide important ecosystem services (e.g., pest control). As a diverse group from different trophic levels, they occupy a variety of ecological niches, making them good indicators of restoration success and habitat quality. To study how different aspects of carabid diversity change along a restoration gradient from degraded grasslands to restored semi‐natural Nardus grasslands, we sampled carabid beetles in grasslands in Northern Belgium. We analysed differences in abundance, diversity and community composition and investigated carabid traits potentially influencing carabids' response to grassland restoration. Species richness did not change along the restoration gradient, but number of individuals decreased as grassland restoration time and effort increased and species composition changed, mostly caused by species turnover. As grassland restoration time and effort increased, carabid body size decreased and the proportion of day‐active carabids increased. Predators and habitat generalists were dominant along the entire gradient. Even though the target vegetation was restored, the carabid communities were not, or at least, did not possess yet traits to be expected from a restored community. The landscape in Northern Belgium might be too fragmented for larger species with low dispersal ability to recolonize restored grasslands. However, restored species‐rich grasslands are beneficial for conservation of meadow birds as day‐active beetles thriving in restored grasslands are an important food source.

Genetic diversity varies with species traits and latitude in predatory soil arthropods (Myriapoda: Chilopoda).

To investigate the drivers of intra-specific genetic diversity in centipedes, a group of ancient predatory soil arthropods. Asia, Australasia and Europe. Present. Centipedes (Class: Chilopoda). We assembled a database of 1245 mitochondrial cytochrome c oxidase subunit I sequences representing 128 centipede species from all five orders of Chilopoda. This sequence dataset was used to estimate genetic diversity for centipede species and compare its distribution with estimates from other arthropod groups. We studied the variation in centipede genetic diversity with species traits and biogeography using a beta regression framework, controlling for the effect of shared evolutionary history within a family. A wide variation in genetic diversity across centipede species (0-0.1713) falls towards the higher end of values among arthropods. Overall, 27.57% of the variation in mitochondrial COI genetic diversity in centipedes was explained by a combination of predictors related to life history and biogeography. Genetic diversity decreased with body size and latitudinal position of sampled localities, was greater in species showing maternal care and increased with geographic distance among conspecifics. Centipedes fall towards the higher end of genetic diversity among arthropods, which may be related to their long evolutionary history and low dispersal ability. In centipedes, the negative association of body size with genetic diversity may be mediated by its influence on local abundance or the influence of ecological strategy on long-term population history. Species with maternal care had higher genetic diversity, which goes against expectations and needs further scrutiny. Hemispheric differences in genetic diversity can be due to historic climatic stability and lower seasonality in the southern hemisphere. Overall, we find that despite the differences in mean genetic diversity among animals, similar processes related to life-history strategy and biogeography are associated with the variation within them.

Heterogeneity in the isolation of patches may be essential for the action of metacommunity mechanisms

The spatial isolation gradient of communities and the gradient in the species dispersal ability are recognized as determinants of biodiversity in metacommunities. In spite of this, mean field models, spatially explicit models, and experiments were mainly focused on idealized spatial arrangements of communities leaving aside the combining role of dispersal and isolation gradients in metacommunity processes. Consequently, we have an incipient understanding of the role of the real spatial arrangement of communities on biodiversity patterns. We focus on six metacommunities for which confident information about the spatial arrangement of water bodies is available. Using coalescent metacommunity models and null models that randomize the location of water bodies, we estimated the potential effect of the landscape on biodiversity and its dependence on species dispersal ability. At extremely low or high dispersal abilities, the location of ponds does not influence diversity because different communities are equally affected by the low or high incoming dispersal. At intermediate dispersal abilities, peripheral communities present a much lower richness and higher beta diversity than central communities. Moreover, metacommunities from real landscapes host more biodiversity than randomized landscapes, a result that is determined by the heterogeneity in the geographic isolation of communities. In a dispersal gradient, mass effects systematically increase the local richness and decrease beta diversity. However, the spatial arrangement of patches only has a large importance in metacommunity processes at intermediate dispersal abilities, which ensures access to central locations but limits dispersal in isolated communities. The ongoing reduction in spatial extent and simplification of the landscape may consequently undermine the metacommunity processes that support biodiversity, something that should be explicitly considered in preserving and restoring strategies.

A systematic revision of the South African Gymnobisiidae (Pseudoscorpiones: Neobisioidea).

The South African fauna of Gymnobisiidae pseudoscorpions is revised. Originally containing only three species in a single genus (Gymnobisium Beier, 1931), results of this study show that there are eight distinct species of the genus within South Africa, five of which are new to science, namely G. capense sp. nov., G. cuneatum sp. nov., G. hogsbackense sp. nov., G. megalodontum sp. nov. and G. prionotogladiatum sp. nov. Three of these, namely G. cuneatum sp. nov., G. hogsbackense sp. nov., and G. inukshuk Harvey and Giribet, 2016 (which is a rare troglobite), are short-range endemics and threatened by habitat loss. Most of the other species, with the exception of G. quadrispinosum (Tullgren, 1907), have small distribution ranges. They are predominantly found inhabiting moist leaf litter of indigenous forests along the coastal provinces, indicating either a low dispersal ability or high niche specificity in these pseudoscorpions. The lack of dense, shaded vegetation between isolated forest patches seems to act as a dispersal barrier for many of the species.

Changes in the functional diversity of modern bird species over the last million years

Despite evidence of declining biosphere integrity, we currently lack understanding of how the functional diversity associated with changes in abundance among ecological communities has varied over time and before widespread human disturbances. We combine morphological, ecological, and life-history trait data for >260 extant bird species with genomic-based estimates of changing effective population size (Ne) to quantify demographic-based shifts in avian functional diversity over the past million years and under pre-anthropogenic climate warming. We show that functional diversity was relatively stable over this period, but underwent significant changes in some key areas of trait space due to changing species abundances. Our results suggest that patterns of population decline over the Pleistocene have been concentrated in particular regions of trait space associated with extreme reproductive strategies and low dispersal ability, consistent with an overall erosion of functional diversity. Further, species most sensitive to climate warming occupied a relatively narrow region of functional space, indicating that the largest potential population increases and decreases under climate change will occur among species with relatively similar trait sets. Overall, our results identify fluctuations in functional space of extant species over evolutionary timescales and represent the demographic-based vulnerability of different regions of functional space among these taxa. The integration of paleodemographic dynamics with functional trait data enhances our ability to quantify losses of biosphere integrity before anthropogenic disturbances and attribute contemporary biodiversity loss to different drivers over time.

Status of Lompoc Yerba Santa Eriodictyon capitatum (Namaceae): an Endangered Plant in Santa Barbara County, Southern California

Lompoc yerba santa Eriodictyon capitatum (Namaceae) is an evergreen shrub endemic to west Santa Barbara County in coastal southern Calif. The species was listed as rare under the Calif. Endangered Species Act in 1979 and as endangered under the U.S. Endangered Species Act in 2000. At Federal listing in 2000, Lompoc yerba santa was known from four locations (five occurrences) in three geographic areas. In 2022, the species is known from 11 occurrences in four geographic populations of which 10 occurrences are considered extant and 1 occurrence likely extirpated: Orcutt Oil Field in the Solomon Hills, 2 occurrences; Burton Mesa on Vandenberg Space Force Base North, 6 occurrences; La Salle Canyon on Vandenberg Space Force Base South, 1 occurrence; and Santa Ynez Mountains, 2 occurrences. Lompoc yerba santa occurs mostly in chaparral and bishop pine (Pinus muricata) forest, and most occurrences are in sandy soil. The species stands up to 5 m tall and with vertical stems up to 10 cm diameter. Much of its reproduction appears to be vegetative by rhizome production, suggesting low dispersal ability, and it is a habitat specialist with apparent dependence on substrate disturbance and fire. Using all available information and international standards with a precautionary but realistic attitude to uncertainty, Lompoc yerba santa in 2022 meets IUCN criteria for endangered status: the small extent of occurrence is 433 km2 (<5,000 km2) and the small area of occupancy is 2.30 km2 (<10 km2), along with the geographic range being severely fragmented, and the quality of habitat is observed/inferred/projected to be in continuing decline (altered fire regime/fire management practices, climate change with severe drought and increased temperatures).