Species Pool Research Articles

Polar lake microbiomes have distinct evolutionary histories.

Toward the poles, life on land is increasingly dominated by microorganisms, yet the evolutionary origin of polar microbiomes remains poorly understood. Here, we use metabarcoding of Arctic, sub-Antarctic, and Antarctic lacustrine benthic microbial communities to test the hypothesis that high-latitude microbiomes are recruited from a globally dispersing species pool through environmental selection. We demonstrate that taxonomic overlap between the regions is limited within most phyla, even at higher-order taxonomic levels, with unique deep-branching phylogenetic clades being present in each region. We show that local and regional taxon richness and net diversification rate of regionally restricted taxa differ substantially between polar regions in both microeukaryotic and bacterial biota. This suggests that long-term evolutionary divergence resulting from low interhemispheric dispersal and diversification in isolation has been a prominent process shaping present-day polar lake microbiomes. Our findings illuminate the distinctive biogeography of polar lake ecosystems and underscore that conservation efforts should include their unique microbiota.

Relationships between species richness and biomass production are context dependent in grasslands differing in land-use and seed addition

Despite evidence from grasslands experiments suggesting that plant species loss reduces biomass production, the strength of biodiversity-ecosystem functioning relationships in managed grasslands is still debated. High land-use intensity and reduced species pools are often suggested to make relationships between biodiversity and productivity less positive or even negative, but concrete evidence is still scarce. We investigated biodiversity-productivity relationships over two years in 150 managed grasslands in Germany. Specifically, we distinguished between relationships of biodiversity and biomass production in managed grasslands (1) varying in land-use intensity (e.g. of mowing, grazing and/or fertilization), (2) where land-use intensity is experimentally reduced, and (3) where additionally to land-use reductions, species pools are enlarged by seed addition. Among grasslands varying in land-use intensity, we found negative biodiversity-productivity relationships. Land-use reduction weakened these relationships, towards neutral, and sometimes, even positive relationships. Seed addition reduced species pool limitations, but this did not strengthen biodiversity-productivity relationships. Our findings indicate that land-use intensity is an important factor explaining the predominantly negative biodiversity-productivity relationships in managed grasslands. While we did not find that species pool limitations weakened biodiversity-productivity relationships, our results are based on a two-year-old experiment, possibly such effects are only visible in the long-term. Ultimately, advancing insights on biodiversity-ecosystem functioning relationships helps us to understand under which conditions agricultural production may benefit from promoting biodiversity.

Dominant species establishment may influence invasion resistance more than phylogenetic or functional diversity

Abstract Phylogenetic and functional diversity are theorised to increase invasion resistance. Experimentally testing whether plant communities higher in these components of diversity are less invasible is an important step for guiding restoration designs. To investigate how phylogenetic and functional diversity of vegetation affect invasion resistance in a restoration setting, we used experimental prairie restoration plots. The experiment crossed three levels of phylogenetic diversity with two levels of functional diversity while species richness was held constant. We allowed invaders to colonise plots; these included native species from neighbouring plots and non‐native invasive species from a surrounding old field. We tested if invader biomass was influenced by phylogenetic and functional diversity, and phylogenetic and hierarchical trait distances between invaders and planted species. We binned each invader into three categories: native species from neighbouring experimental plots (site‐specific invaders), native species not part of the experimental species pool (native invaders) or non‐native species (non‐native invaders). Counter to expectation, both non‐native and native invaders became more abundant in more phylogenetically diverse plots. However, plots with higher abundance of planted Asteraceae, a dominant family of the tallgrass prairie, had lower invader biomass for both native and non‐native invaders. We also found that hierarchical trait differences shaped invasion. The species that became most abundant were non‐native invaders that were taller, and native invaders with low specific leaf area relative to planted species. Site‐specific invaders were not influenced by any plot‐level diversity metrics tested. Synthesis and application: Our results suggest that greater phylogenetic diversity may lower resistance to invasion. This effect may be due to more even but sparser niche packing in high‐diversity plots, associated with greater availability of unsaturated niche space for colonisation. However, trait composition fostered invasion resistance in two ways in our study. First, establishment of native species with strongly dominant traits may confer invasion resistance. Second, species mixes that optimise trait differences between planted vegetation and likely invaders may enhance invasion‐resistance.

RESPUESTA DE TRES ESPECIES MADERABLES DE RÁPIDO CRECIMIENTO A DIFERENTES BIOCLIMAS EN ECUADOR

<p><strong>Background:</strong> The timber sector in Ecuador holds promising potential for growth and development. The intensive utilization of native taxa has depleted their genetic species pool, making them increasingly scarce in meeting the rising demand for wood. Consequently, there has been a growing exploration of new fast-growing forest species to serve as alternatives for lumber and biomass production. <strong>Objective: </strong>To assess the suitability of Andean bioclimatic conditions for the introduction of three tree species: <em>Paulownia elongata, P. fortunei</em>, and the hybrid <em>P. elongata x P. fortunei</em>. This work primarily focused in investigating whether plant density impacts the initial growth of individual tree growth and whether there is a co-dependence between site conditions and plant density in each of the three species. <strong>Methodology:</strong> The National Autonomous Institute of Farming Research (INIAP) imported 3000 seedlings, each about 10cm tall, of <em>Paulownia e</em>longata, <em>Paulownia fortunei</em>, and the hybrid <em>Paulownia elongata</em> x <em>Paulownia fortunei</em> from the World Paulownia Institute of Georgia - USA. Four experimental sites were selected in two regions of Ecuador: humid tropics (Quevedo and Santo Domingo de los Tsachilas), dry sub-peak (el Almendral) and Andes (Riobamba), each site is located at different altitudes. At each site, the experiment was set up in a spatial split-plot arrangement with randomized complete blocks. Three blocks were established, two planting frames (3x3 m and 4x4 m) and the three selected <em>Paulownia</em> species. The three blocks were laid off randomly in each experiment. The two planting frames were randomly placed within each block, and the three species were randomly planted within each planting frame. The experimental subjects (plant species) consisted of nine individuals. <strong>Results:</strong> Plants with higher height and diameter are located in areas with lower elevation, with hybrid Paulownia displaying better performance in high densities. All species showed a survival rate above 85% one-year post-establishment. However, the lowest survival is found in areas above 2000 m. <strong>Implications:</strong> High elevations restrict the individual growth of Paulownia in Andean conditions, but low altitudes enhance it. <strong>Conclusion:</strong> The three specimens performed reasonably well during one-year post-establishment. However, it is necessary to continue observing their growth until they reach their asymptotic point, determining their volumetric yield.</p>

The neglected roles of adjacent natural ecosystems in maintaining bacterial diversity in agroecosystems.

A central aim of community ecology is to understand how local species diversity is shaped. Agricultural activities are reshaping and filtering soil biodiversity and communities; however, ecological processes that structure agricultural communities have often overlooked the role of the regional species pool, mainly owing to the lack of large datasets across several regions. Here, we conducted a soil survey of 941 plots of agricultural and adjacent natural ecosystems (e.g., forest, wetland, grassland, and desert) in 38 regions across diverse climatic and soil gradients to evaluate whether the regional species pool of soil microbes from adjacent natural ecosystems is important in shaping agricultural soil microbial diversity and completeness. Using a framework of multiscales community assembly, we revealed that the regional species pool was an important predictor of agricultural bacterial diversity and explained a unique variation that cannot be predicted by historical legacy, large-scale environmental factors, and local community assembly processes. Moreover, the species pool effects were associated with microbial dormancy potential, where taxa with higher dormancy potential exhibited stronger species pool effects. Bacterial diversity in regions with higher agricultural intensity was more influenced by species pool effects than that in regions with low intensity, indicating that the maintenance of agricultural biodiversity in high-intensity regions strongly depends on species present in the surrounding landscape. Models for community completeness indicated the positive effect of regional species pool, further implying the community unsaturation and increased potential in bacterial diversity of agricultural ecosystems. Overall, our study reveals the indubitable role of regional species pool from adjacent natural ecosystems in predicting bacterial diversity, which has useful implication for biodiversity management and conservation in agricultural systems.

Species–area relationships of plants and microbes are driven by different mechanisms in patchy grassland fragments

Abstract The island species–area relationship (SAR) describes how the number of species on an island varies with its area and provides important information about the maintenance of species diversity and how species might be lost as habitats are lost and fragmented. While the island SAR has been widely studied among macroorganisms, patterns for soil microbes have been less forthcoming, as have analyses of potential underlying mechanisms. We examined the SAR patterns of plants, soil fungi and bacteria among remnant grassland fragments isolated by degraded habitat matrix in a steppe grassland. As expected, we found that the total species richness of plants, fungi and bacteria in the entire fragment decreased with decreasing fragment area. However, the mechanisms differed among taxa. For plants, the lower diversity was most likely because of decreases in habitat quality and habitat heterogeneity on smaller fragments. For fungi, we found similar results, but also an important interaction with plant diversity, suggesting they were coupled via their functional associations. For bacteria, the lower diversity on smaller fragments primarily resulted from a sampling effect from the larger species pool, which outweighed the effect of higher habitat heterogeneity on smaller fragments. Synthesis: Our study highlights that fragmentation‐induced loss of diversity can have many different underlying mechanisms and that understanding these mechanisms can provide useful insights to project future biodiversity loss and conservation.

Environmental filtering and biotic interactions act on different facets of the diversity of benthic assemblages associated with eelgrass.

Eelgrass supports diverse benthic communities that ensure a variety of ecosystem functions. To better understand the ecological processes that shape community composition in eelgrass at local and regional scales, taxonomic and functional α- and β-diversity were quantified for communities inhabiting five meadows in France. The extent to which environmental factors affected local and regional benthic communities was quantified by considering their direct and indirect effects (through morphological traits of eelgrass) using piecewise structural equation modeling (pSEM). Communities supported by eelgrass had higher species abundances, as well as taxonomic and functional diversity compared to nearby bare sediments. No significant differences were found between communities from the center relative to the edges of meadows, indicating that both habitats provide similar benefits to biodiversity. The presence of a few abundant species and traits suggests moderate levels of habitat filtering and close associations of certain species with eelgrass. Nevertheless, high turnover of a large number of rare species and traits was observed among meadows, resulting in meadows being characterized by their own distinct communities. High turnover indicates that much of the community is not specific to eelgrass, but rather reflects local species pools. pSEM showed that spatial variation in community composition (β-diversity) was primarily affected by environmental conditions, with temperature, current velocity, and tidal amplitude being the most significant explanatory variables. Local richness and abundance (α-diversity) were affected by both environment and morphological traits. Importantly, morphological traits of Zostera marina were also influenced by environmental conditions, revealing cascading effects of the environment on assemblages. In sum, the environment exerted large effects on community structure at both regional and local scales, while plant traits were only pertinent in explaining local diversity. This complex interplay of processes acting at multiple scales with indirect effects should be accounted for in conservation efforts that target the protection of biodiversity.

AEGILOPS L. GENETIC DIVERSITY IN SOUTHWESTERN REGION OF UZBEKISTAN

As wheat donors, wild species of the genus Aegilops L. play a vital role in practical breeding to improve wheat production because of their strong relationship and wide genetic diversity. Using nine simple sequence repeat (SSR) markers helped assess the genetic diversity in 96 collected samples of four species belonging to the genus Aegilops, i.e., Aegilops tauschii Coss (D), Ae. cylindrica Host (CD), Ae. crassa Boiss (DDM), and Ae. triuncialis L. (UC). The said collection came from 21 sites of various expeditions located in three regions of Southwestern Uzbekistan (Samarkand, Urgut, Kitab, and Shakhrisabz regions). Generally, 102 distinct alleles were found, with an average of 11.33 alleles per primer. The total number of species-specific amplicons was 35. The polymorphism detected varied from 28.6% (for the WSP107 primer) to 77.0% (for the WSP130 and WSP192 primers). The mean values of polymorphism information content (PIC) and expected heterozygosity (Ho) for all samples were 0.675 and 0.527, respectively. Based on nine SSR markers, on average, the genetic distance indices (GD) varied from 0.63 to 0.77. The highest genetic similarity (GD = 0.77) recorded occurred between the species Ae. crassa and Ae. cylindrica, whereas the least (GD = 0.48), between Ae. cylindrica and Ae. triuncialis with their taxonomic classification. Genus Aegilops samples from the same region often attain an identical subgrouping, which might be due to relatedness by genetic parameters. The gene pool of native species of the genus Aegilops from the Southwestern region of Uzbekistan may provide suitable alleles for wheat improvement and adaptation in the future.

Planning insect surveys in alpine ecosystems

Most biological survey programs rely on multi-species inventories (e.g. birds, amphibians, butterflies, dragonflies). These programs usually rely on multiple visits during pre-defined time windows. The implicit goal of this popular approach is to maximize the observed species richness. Here, we present a novel method to optimize the timing of survey windows using a framework maximizing the detectable species pool. We present a proof of concept using 20 years of entomological records in Switzerland using butterflies, dragonflies, and grasshoppers. The general framework presented can potentially be applied to a wide range of biological survey schemes. It offers a new practical tool for adaptive entomological monitoring under climate change.

Germination performance of alien and native species could shape community assembly of temperate grasslands under different temperature scenarios

Rising temperatures due to climate change are expected to interplay with biological invasions, and may enhance the spread and growth of some alien species upon arrival in new areas. To successfully invade, a plant species needs to overcome multiple biological barriers. Among the crucial life stages, seed germination greatly contributes to the final species assembly of a plant community. Several studies have suggested that alien plant success is related to their high seed germination and longevity in the soil. Hence, our aim is to test if the germination potential of alien seeds present in the seed bank will be further enhanced by future warming in temperate dry grasslands, an ecosystem that is among those most prone to biological invasions. We designed a laboratory germination experiment at two temperatures (20 and 28 °C), to simulate an early or late heat wave in the growing season, using seeds from nine common grassland Asteraceae species, including native, archaeophyte and neophyte species. The test was performed on both single and mixed pools of these categories of species, using a full-factorial orthogonal design. The warmer germination temperature promoted neophyte success by increasing germination probability and germination speed, while negatively impacting these parameters in seeds of native species. The co-occurrence of native and archaeophyte seeds at the lower temperature limited the invasiveness of neophytes. These results provide important information on future management actions aimed at containing alien plant invasions, by improving our knowledge on the possible seed-bank response and interaction mechanisms of common species occurring in disturbed natural areas or restored sites.Graphical abstractSummary of the experimental results. The colour of the flowers represent the status, divided as native (blue), neophyte (red) and archaeophyte (green). Each flower symbol represents the species pool for each plant category (i.e. NA = Buphthalmum salicifolium, Carlina vulgaris, Centaurea scabiosa; NE = Artemisia annua, Symphyotrichum novi-belgii, Senecio inaequidens; AR = Centaurea cyanus, Cichorium intybus, Tripleurospermum inodorum). The number of flowers represent the germination percentage of the various category assembly. In the columns are divided the various combination. From up to bottom the trend of germination percentage at 20 and 28 °C are shown.

Does non‐native diversity mirror Earth's biodiversity?

AbstractAimHuman activities have introduced numerous non‐native species (NNS) worldwide. Understanding and predicting large‐scale NNS establishment patterns remain fundamental scientific challenges. Here, we evaluate if NNS composition represents a proportional subset of the total species pool available to invade (i.e. total global biodiversity), or, conversely, certain taxa are disproportionately pre‐disposed to establish in non‐native areas.LocationGlobal.Time periodPresent day.Major taxa studiedGlobal diversity.MethodsWe compiled one of the most comprehensive global databases of NNS (36,822 established species) to determine if NNS diversity is a representative proportional subset of global biodiversity.ResultsOur study revealed that, while NNS diversity mirrors global biodiversity to a certain extent, due to significant deviance from the null model it is not always a representative proportional subset of global biodiversity. The strength of global biodiversity as a predictor depended on the taxonomic scale, with successive lower taxonomic levels less predictive than the one above it. Consequently, on average, 58%, 42% and 28% of variability in NNS numbers were explained by global biodiversity for phylum, class and family respectively. Moreover, global biodiversity was a similarly strong explanatory variable for NNS diversity among regions, but not habitats (i.e. terrestrial, freshwater and marine), where it better predicted NNS diversity for terrestrial than for freshwater and marine habitats. Freshwater and marine habitats were also greatly understudied relative to invasions in the terrestrial habitats. Over‐represented NNS relative to global biodiversity tended to be those intentionally introduced and/or ‘hitchhikers’ associated with deliberate introductions. Finally, randomness is likely an important factor in the establishment success of NNS.Main conclusionsBesides global biodiversity, other important explanatory variables for large‐scale patterns of NNS diversity likely include propagule and colonization pressures, environmental similarity between native and non‐native regions, biased selection of intentionally introduced species and disparate research efforts of habitats and taxa.

Controlling for the effects of environmental availability when testing how the environment determines community compositional uniqueness

Abstract Identifying the drivers that promote unique species compositions (i.e. ecological uniqueness) is crucial to understanding the mechanisms underpinning diversity patterns and for effective conservation planning. Environmental conditions are often sampled differentially in datasets, which can lead to rarer environments having unique species compositions, provided that environmental differences increase compositional differences. This effect, however, will be undesirable when a study aims to test the direct impact of environments rather than their availability. We developed an approach to reduce the effects of environmental availability in ecological uniqueness analyses through calculating expected pairwise compositional dissimilarities for each unique environmental condition. We further used simulations to assess the performance of our methods by randomly generating communities from two hypothetical environments with non‐overlapping species pools. Additionally, we used a dataset of 50 tree communities to demonstrate how environmental availability could impact relationships between environmental conditions and ecological uniqueness in empirical studies. Our simulations revealed that uniqueness metrics based on observed values are sensitive to environmental availability, while our approach correctly concluded that there were no differences among environments under the unbalanced design. Our analysis of tree communities produced divergent conclusions between the two approaches, as increasing slope reduced ecological uniqueness after controlling for their low availability in the dataset only. This suggests that low environmental availability inflated the ecological uniqueness of sites with high slope, which opposed its direct negative effects on ecological uniqueness, leading to a weak relationship based on observed values. To achieve a more mechanistic understanding of ecological uniqueness patterns, the effects of environmental availability must be considered. We recommend that studies use both uncorrected and corrected analyses to identify not only the direct effects of environmental conditions but also the degree to which their availability influences the observed relationships between ecological uniqueness and environment conditions. Our approach should be most necessary and applicable in unbalanced designs, which is a common characteristic in empirical studies.

Representation of in situ forest genetic resources of broadleaf tree species according to forest types in the Right-Bank Forest-Steppe of Ukraine

The article analyzes the formation and localization of in situ forest genetic resource conservation facilities in the conditions of the Right Bank Forest-Steppe of Ukraine in terms of the main forest types. Peculiarities of the state and selection structure of the forest genetic reserves (FGR) and plus stands (PS) were studied. The established that the largest area of forest genetic reserves and plus stands of broadleaves forests within the Right Bank Forest-Steppe is concentrated in the Vinnytsia region, based on the results of the research. The largest number and largest areas of these objects are concentrated in this region. It was established that the largest area of FGR located in fresh forest type conditions — 3475.9 ha, according to the distribution of forest genetic reserves and plus stands. The largest number of objects — 92 (78.0%) — is concentrated in this type of forest. The largest area of FGR is concentrated in fresh hornbeam beech — 842.3 ha in the Roztoch-Opil district of the forest typological region. There are 44 genetic reserves located in the conditions of the Podilsk sector of the Polysk-Prikarpattia district of wet hornbeam forests of the forest typological region of the wet cluster 3d. The largest area of forest stands is fresh beech forest — 234.0 ha. There are 40 FGR with a total area of 2,001 hectares of fresh hornbeam forests in the Podilskyi and Pravoberezhny sectors of the Dnipro tipologycal district. Forest genetic reserves are mainly concentrated in fresh hornbeam forest — 1584.6 hectares (29 units). The representation of the objects of in situ conservation of the gene pool of forest tree species in terms of forest types is insufficient and reflects only 16% of the entire diversity of forest ecosystems within the boundaries of the Roztoch-Opil district and 21–24% of the Dnipro districts of Polisko-Prikarpatskiy. This requires the introduction of measures for the additional creation of forest genetic reserves in other types of forest with the aim of the widest possible representation of the ecosystem diversity of the forest landscapes of the region.

Forest recovery by direct seeding on the southern edge of the Brazilian Amazon

Broad‐scale parameters are crucial for the restoration of forest to align with the United Nations resolutions for the “Decade on Ecosystem Restoration.” Direct seeding is a moderately priced, active method with potential use in forest recovery. This study evaluated the recovery of woody vegetation from 23 restored forests (RF) located on the southern edge of the Brazilian Amazon, a region known as the “Arc of Deforestation”. We ask: (1) What are the differences in abundance, species richness, and alpha diversity between seeded and regenerated species in RF? (2) How does the structure, floristic composition, species richness, and alpha diversity of RF compare with adjacent primary forests (PF)? After 12 years of intervention, our results reveal that RFs exhibited lower species richness, alpha diversity, aboveground biomass (AGB), basal area, and dissimilar floristic composition when compared to PFs. Recovery in PFs reached 40% for AGB, 55% for basal area, 24% for alpha diversity, and 60% for species richness. These findings indicate ongoing recovery of evaluated parameters, highlighting the success of the seeding method in restoring degraded riparian forests. We also observed similar species richness between seeded and regenerated species in RFs, yet absolute density, AGB, and alpha diversity were higher in seeded species. The notable presence of non‐seeded species in our plots provides evidence that direct seeding fosters spontaneous regeneration from the regional species pool. Our findings suggest that direct seeding is a viable option for restoring forest structure and diversity in areas with limited or no potential for passive regeneration.

A roadmap for pyrodiversity science

AbstractBackgroundContemporary and projected shifts in global fire regimes highlight the importance of understanding how fire affects ecosystem function and biodiversity across taxa and geographies. Pyrodiversity, or heterogeneity in fire history, is often an important driver of biodiversity, though it has been largely overlooked until relatively recently. In this paper, we synthesise previous research to develop a theoretical framework on pyrodiversity–biodiversity relationships and propose future research and conservation management directions.Theoretical FrameworkPyrodiversity may affect biodiversity by diversifying available ecological niches, stabilising community networks and/or supporting diverse species pools available for post‐fire colonisation. Further, pyrodiversity's effects on biodiversity vary across different spatial, temporal and organismal scales depending on the mobility and other life history traits of the organisms in question and may be mediated by regional eco‐evolutionary factors such as historical fire regimes. Developing a generalisable understanding of pyrodiversity effects on biodiversity has been challenging, in part because pyrodiversity can be quantified in various ways.Applying the Pyrodiversity ConceptExclusion of Indigenous fire stewardship, fire suppression, increased unplanned ignitions and climate change have led to dramatic shifts in fire regimes globally. Such shifts include departures from historic levels of pyrodiversity and add to existing challenges to biodiversity conservation in fire‐prone landscapes. Managers navigating these challenges can be aided by targeted research into observed contemporary pyrodiversity–biodiversity relationships as well as knowledge of historical reference conditions informed by both Indigenous and local ecological knowledge and western science.Future Research DirectionsSeveral promising avenues exist for the advancement of pyrodiversity science to further both theoretical and practical goals. These lines of investigation include but are not limited to (1) testing the increasing variety of pyrodiversity metrics and analytical approaches; (2) assessing the spatial and temporal scale‐dependence of pyrodiversity's influence; (3) reconstructing historical pyrodiversity patterns and developing methods for predicting and/or promoting future pyrodiversity; and (4) expanding the focus of pyrodiversity science beyond biodiversity to better understand its influence on ecosystem function and processes more broadly.

Graph embedding and transfer learning can help predict potential species interaction networks despite data limitations

Abstract Metawebs (networks of potential interactions within a species pool) are a powerful abstraction to understand how large‐scale species interaction networks are structured. Because metawebs are typically expressed at large spatial and taxonomic scales, assembling them is a tedious and costly process; predictive methods can help circumvent the limitations in data deficiencies, by providing a first approximation of metawebs. One way to improve our ability to predict metawebs is to maximize available information by using graph embeddings, as opposed to an exhaustive list of species interactions. Graph embedding is an emerging field in machine learning that holds great potential for ecological problems. Here, we outline how the challenges associated with inferring metawebs line‐up with the advantages of graph embeddings; followed by a discussion as to how the choice of the species pool has consequences on the reconstructed network, specifically as to the role of human‐made (or arbitrarily assigned) boundaries and how these may influence ecological hypotheses.

Ecological and Floristic Plant Surveys of Little Wabash River Nature Preserve, Indiana

Forests in northeastern Indiana are relegated to relatively small fragments and have become important patches in a landscape dominated by agriculture. Little Wabash River Nature Preserve is a property in Allen County, Indiana, closed to the public and protected by ACRES Land Trust. We conducted ecological surveys at 48 regular plots located along seven transects through the property that consisted of identifying and counting individual plants at understory, midstory, and overstory strata and recording several ecological factors. These were augmented by floristic meandering surveys during the growing season of 2019 to record plant species that may not have been encountered at the ecological plots and thereby give a fuller picture of the floristic composition of the property. We encountered a total of 251 identified species during the ecological and floristic surveys. Analysis showed understory abundance, richness, and diversity were positively related to available light (photosynthetically active radiation) and negatively related to canopy cover. The most abundant species in the midstory were non-native species. Juglans nigra had the greatest frequency and dominance in the overstory. In nonmetric multidimensional scaling, there was clear separation of the plant community within the forested portion from the community in the adjacent to the small old-field. Mean C-value for the site was 2.87, which resulted in a 41.56 FQI. The FQI may be an over-estimation of the conservation importance of the site and the Mean C-value may be an under-estimation of that importance. Overall, the Nature Preserve provides an example of the plant diversity can exist in a small, protected forest. While there are some common non-native species, there is habitat for a relatively large pool of species and may be of importance for protection within the surrounding disturbed landscape.

The ecological footprint of outdoor activities: Factors affecting human-vectored seed dispersal on clothing

In the Anthropocene, humans are among the most abundant long-distance seed dispersal vectors globally, due to our increasing mobility and the growing global population. However, there are several knowledge gaps related to the process of human-vectored dispersal (HVD) on clothing. In a multi-site field experiment covering various habitat types in three countries of Central-Europe, we involved 88 volunteer participants and collected 251 HVD samples and 2008 subsamples from their socks and shoes. We analysed the number of diaspores and species in the samples. Specifically, we studied the effects of site characteristics (variables related to habitat types and season), vector characteristics (activity type, gender, clothing type, shoe type) and plant characteristics (species pool of the visited habitats and plant traits) on the number of diaspores and array of species dispersed. We assessed the habits of people that could be relevant for HVD with a questionnaire survey. A total of 35,935 diaspores of 229 plant taxa were identified from the samples, which indicates a huge potential of HVD in dispersing diaspores across habitats and regions. Most diaspores were recorded in grassland habitats, and more diaspores were dispersed during fieldwork than excursions. Clothing type also played a decisive role: there were more diaspores and species when wearing short-top shoes and short trousers than long ones. Even though our study was carried out mainly in natural or semi-natural habitats, a large number of dispersed species were disturbance-tolerants and weeds and only a few were specialists, suggesting the controversial role of HVD in conservation. At the individual level, people can reduce the number of diaspores through their clothing choices and diaspore removal habits, while providing adequate equipment for staff, operating cleaning stations, and increasing awareness of employees are main ways in which unintended diaspore dispersal can be tackled at the institutional level.

A detailed stratigraphic and taphonomic reassessment of the late Paleozoic fossil flora from Promontory Butte, Arizona

A late Paleozoic, likely early Late Pennsylvanian (Missourian/early Virgilian), flora from Promontory Butte, Arizona, USA is the westernmost assemblage of this age yet described from northern Pangea. The palynological species pool is similar to that typical of more central parts of the supercontinent; in contrast, the macroflora differs by facies, reflective of original habitat differentiation. The flora is preserved in a succession that includes sandstone, siltstone, shale, and conglomerate in an upward-fining series of beds. A break between the siltstone and shale is marked by an organic-shale bed, previously described as a coal, and its underclay/paleosol. This stratigraphic unit is interpreted as an active channel fill terminating in a lake. A detailed bed-by-bed facies analysis of the macroflora, focusing on the relationship between sedimentological features and fossil-plant composition reveals that the wetland floral elements are concentrated in the upper, fine-grained beds of the fill, including the organic shale and overlying mudrock, whereas the drought-tolerant, xeromorphic plants are concentrated in siltstones and sandy siltstones below the organic-shale/underclay couplet. Palynology, in contrast, suggests a uniform flora throughout the interval, indicating that macrofloral changes within the channel-fill sequence reflect microhabitat differences resulting from local changes in soil moisture conditions rather than climate change. The palynoflora is dominated by tree ferns and compositionally suggests a Missourian (Kasimovian) age, possibly early Virgilian; rare lycospore grains, characteristic of the Middle Pennsylvanian, are likely reworked from older sediments. Earlier collecting at this site did not sort the fossils by microstratigraphy and facies types, combining all floral levels into one assemblage that indicated possible co-occurrence of wetland plants and plants tolerant of seasonal moisture stress. Furthermore, a Pennsylvanian-Permian boundary age was inferred due to the abundance of xeromorphic, drought-tolerant taxa. In light of this investigation, a late Missourian age is inferred as most likely.

The poleward naturalization of intracontinental alien plants.

Plant introductions outside their native ranges by humans have led to substantial ecological consequences. While we have gained considerable knowledge about intercontinental introductions, the distribution and determinants of intracontinental aliens remain poorly understood. Here, we studied naturalized (i.e., self-sustaining) intracontinental aliens using native and alien floras of 243 mainland regions in North America, South America, Europe, and Australia. We revealed that 4510 plant species had intracontinental origins, accounting for 3.9% of all plant species and 56.7% of all naturalized species in these continents. In North America and Europe, the numbers of intracontinental aliens peaked at mid-latitudes, while the proportion peaked at high latitudes in Europe. Notably, we found predominant poleward naturalization, primarily due to larger native species pools in low-latitudes. Geographic and climatic distances constrained the naturalization of intracontinental aliens in Australia, Europe, and North America, but not in South America. These findings suggest that poleward naturalizations will accelerate, as high latitudes become suitable for more plant species due to climate change.