Biodiversity Patterns Research Articles

Unearthing the Past for a Sustainable Future: Extracting and transforming data in the Biodiversity Heritage Library for climate action

As the urgency to address the climate crisis intensifies, the availability of accurate and comprehensive biodiversity data has become crucial for informing climate change studies, tracking key environmental indicators, and building global biodiversity monitoring platforms. The Biodiversity Heritage Library (BHL) plays a vital role in the core biodiversity infrastructure, housing over 60 million pages of digitized literature about life on Earth. Recognizing the value of over 500 years of data in BHL, a global network of BHL staff is working to establish a scalable data pipeline to provide actionable occurrence data from BHL’s vast and diverse collections. However, transforming textual content into FAIR (findable, accessible, interoperable, reusable) data poses challenges due to missing descriptive metadata and error-ridden unstructured outputs from commercial text engines. (Fig. 1) Despite the wealth of knowledge in BHL now available to global audiences, the underutilization of biodiversity and climate data contained in BHL's textual corpus hinders scientific research, hampers informed decision-making for conservation efforts, and limits our understanding of biodiversity patterns crucial for addressing the climate crisis. By leveraging recent advancements in text recognition engines, along with cutting-edge AI (Artificial Intelligence) models like OpenAI’s CLIP (Contrastive Language-Image Pre-Training) and nascent features in transcription platforms, BHL staff are beginning to process vast amounts of textual and image data and transform centuries worth of data from BHL collections into computationally usable formats. Recent technological breakthroughs now offer a transformative opportunity to empower the global biodiversity community with prescient insights from our shared past and facilitate the integration of historical knowledge into climate action initiatives. To bridge gaps in the historical record and unlock the potential of the Biodiversity Heritage Library (BHL), a multi-pronged effort utilizing innovative cross-disciplinary approaches is being piloted. These technical approaches were selected for their efficiency and ability to generate rapid results that could be applied across the diverse range of materials in BHL. (Fig. 2) Piloting a data pipeline that is scalable to 60 million pages requires considerable investigation, experimentation, and resources but will have an appreciable impact on global conservation efforts by informing and establishing historic baselines deeper into time. This presentation will focus on the identification, extraction, and transformation of OCR into structured data outputs in BHL. Approaches include: Upgrading legacy OCR text using Tesseract OCR engine to improve data quality by 20% and openly publish 40 GBs of textual data as FAIR data; Evaluating handwritten text recognition (HTR) engines (Microsoft Azure Computer Vision, Google Cloud Vision API (Application Programming Interface), and Amazon Textract) to improve scientific name-finding in BHL’s handwritten archival materials using algorithms developed by Global Names Architecture; Extracting data from collecting events using HTR coordinate outputs with Python library Pandas DataFrame to create structured data; Classifying BHL page-level images with OpenAI's CLIP, a neural network model to accurately identify the handwritten sub-corpus of primary source materials in BHL; Running an A/B test to evaluate the efficiency and accuracy of human-keyed transcription data extraction to provide high-quality, human-vetted datasets that can be deposited with data aggregators. Upgrading legacy OCR text using Tesseract OCR engine to improve data quality by 20% and openly publish 40 GBs of textual data as FAIR data; Evaluating handwritten text recognition (HTR) engines (Microsoft Azure Computer Vision, Google Cloud Vision API (Application Programming Interface), and Amazon Textract) to improve scientific name-finding in BHL’s handwritten archival materials using algorithms developed by Global Names Architecture; Extracting data from collecting events using HTR coordinate outputs with Python library Pandas DataFrame to create structured data; Classifying BHL page-level images with OpenAI's CLIP, a neural network model to accurately identify the handwritten sub-corpus of primary source materials in BHL; Running an A/B test to evaluate the efficiency and accuracy of human-keyed transcription data extraction to provide high-quality, human-vetted datasets that can be deposited with data aggregators. The ongoing development of a scalable data pipeline of BHL’s relevant biodiversity and climate-related datasets requires sustained support and partnership with the biodiversity community. Initial results demonstrate that liberating data from archival and handwritten field notes is arduous but feasible. Extending these methodologies to the broader scientific literature presents new research opportunities. Extracting and normalizing data from unstructured textual sources can significantly advance biodiversity research and inform environmental policy. The Biodiversity Heritage Library staff are committed to building multiple scalable data pipelines with the ultimate goal of erecting a global biodiversity knowledge graph, rich in interconnected data and semantic meaning, enabling informed decisions for the preservation and sustainable management of Earth's biodiversity.

Taxonomic and phylogenetic perspectives reveal the community assembly of different forest strata along an altitudinal gradient

AbstractDisentangling the distribution patterns of biodiversity along altitudinal gradients and their drivers has been a hot topic in ecological research. Different forest strata show multiple distribution patterns influenced by different community assembly mechanisms. Here, we measure the dominant ecological processes affecting three forest strata (tree, shrub, and herb layers) along altitudinal gradients. We sampled plants with different forest strata in 21 plots located from 2500 to 3700 m in Lasha Mountain, northwestern Yunnan. The taxonomic alpha diversity of the herb layer showed a monotonic decreasing trend with increasing altitude, while the shrub layer was characterized by a single peak, and the tree layer showed no significant change with increasing altitude. We observed a decreasing pattern of phylogenetic diversity with increasing altitude in the herb layer, whereas phylogenetic diversity did not change in the tree and shrub layers. The phylogenetic structure of these three layers showed the same pattern: phylogenetic clustering at low altitudes and overdispersion at middle and high altitudes. The diversity and phylogenetic structure of the herb layer were driven by climate (average dry season precipitation) and topographic (slope and aspect) factors, while shrub layer diversity was mainly influenced by tree layer richness. Overall, the phylogenetic structure pattern of the three forest strata changed from clustered to overdispersed with increasing altitude, indicating that environmental filtering was the main driver at low altitudes, while interspecific competition dominated at middle and high altitudes.

Human impact on vegetation at Lago di Vedana (Dolomites, Northern Italy) during the last seven centuries

Studying the legacies of past human-environment interactions is essential for understanding current landscape and biodiversity patterns. Human influences on past terrestrial and aquatic vegetation are reconstructed based on palynological analysis conducted on a sediment core from Lago di Vedana (Province of Belluno, Northern Italy). This study represents the first pollen record from the Dolomitic lowlands with varying anthropogenic influences throughout the last 700 years. The radiocarbon-dated pollen record begins ca. A.D. 1300 with semi-open forest and moderate human impact, possibly due to activities of the nearby hospice of San Gottardo. Human impact increased with the foundation of the Vedana Charterhouse in the immediate catchment of the lake in A.D. 1457. Activities of the monks involved extensive forest clearing, cultivation of Cannabis/Humulus and possibly hemp retting. In the 19th century the composition of cultivated species changed following the transformation of the Charterhouse into a farm. The 20th century is characterized by expansion of forest taxa and a distinct decline of human influences, probably due to a rural exodus and abandonment of agricultural activities. Vegetation development at Lago di Vedana is consistent with general trends in the Italian Alps and reveals local cultivation practices. The results illustrate the close intertwinement of climatic trends and local human influences, modulated by regional socio-cultural developments during the last millennium.

BIRD DIVERSITY ACROSS AN ANDEAN CITY: THE LIMITATION OF SPECIES RICHNESS VALUES AND WATERSHED SCALES

Evaluating several biodiversity descriptors and considering several spatial scales might elucidate conservation issues and improve biodiversity monitoring in urban environments. We estimated species richness (order q = 0), Shannon diversity (order q = 1), and Simpson diversity (order q = 2) based on Hill numbers and performed cluster analysis and non-metric multidimensional scaling (NMDS) to compare seven urban micro-watersheds and a peri-urban site across a northern Andean city (Medellín, Colombia). We found 113 diurnal resident bird species: 50 (44 %) exclusively within urban sites, 21 (19 %) exclusively in the periurban site, and 42 (37 %) shared species. Some urban watersheds had similar bird species richness to the periurban site, but Shannon and Simpson diversities were always lower, showing decrease in local bird diversity when abundances were considered. Bird species composition differed between urban watersheds and the periurban site, with all urban watersheds grouped altogether by cluster and NMDS analysis, and the periurban site forming its own group. This suggests homogenization of bird species composition due to the species turnover decreasing across urban areas, with endemic, near endemic and rare species restricted to periurban areas where native forest remnants persist. Several scales of biodiversity and analysis at more local scales are needed to better understand biodiversity patterns across Andean cities and to design urban planning strategies that prevent biodiversity loss.

Pedogenesis of typical zonal soil drives belowground bacterial communities of arable land in the Northeast China Plain

Belowground bacterial communities play essential roles in maintaining ecosystem multifunction, while our understanding of how and why their distribution patterns and community compositions may change with the distinct pedogenetic conditions of different soil types is still limited. Here, we evaluated the roles of soil physiochemical properties and biotic interactions in driving belowground bacterial community composition across three typical zonal soil types, including black calcium soil (QS), typical black soil (HL) and dark brown soil (BQL), with distinct pedogenesis on the Northeast China Plain. Changes in soil bacterial diversity and community composition in these three zonal soil types were strongly correlated with soil pedogenetic features. SOC concentrations in HL were higher than in QS and BQL, but bacterial diversity was low, and the network structure revealed greater stability and connectivity. The composition of the bacterial community correlated significantly with soil pH in QS but with soil texture in BQL. The bacterial co-occurrence network of HL had higher density and clustering coefficients but lower edges, and different keystone species of networks were also detected. This work provides a basic understanding of the driving mechanisms responsible for belowground bacterial biodiversity and distribution patterns over different pedogenetic conditions in agroecosystems.

Knowledge shortfalls for titi monkey: A poorly known clade of small-bodied South American primates

Titi monkeys (Callicebus, Cheracebus, and Plecturocebus) comprise the most species-rich group of primates in South America. Thirty-six currently recognized species composing this group inhabit a multitude of habitats across most of South America. While field-based and laboratory research has provided insights into the behavior, ecology, and physiology of some titis, multiple knowledge gaps regarding their biodiversity patterns persist. Here, we provide an overview of titi research and identify their biodiversity knowledge shortfalls. Using online databases, we collated the literature of all titi studies published up to December 31, 2021. We compiled 521 publications, with 48 % representing in situ field studies of the monkeys. The majority of field-based publications focused on studies conducted in Brazil and Peru. We found that research efforts have increased in recent decades, as indicated by the increased number of publications on titis. However, given the large number of species and their wide distribution across South America, there is limited information about most of these species and their geographic ranges. By highlighting the focal points where conservation-related data are still required, our findings demonstrate the importance of expanding research efforts and investment on the full extent of titi species and their entire geographic regions; doing so will help fill the knowledge shortfalls rather than solely advancing the study of a restricted range of topics in one or two habitats or countries. These advances will contribute to fill knowledge gaps through the creation/expansion of data repositories, citizen science programs, and increased financial support to maintain long-term data collection.

Inferring alpha, beta, and gamma plant diversity across biomes with GEDI spaceborne lidar

Biodiversity-structure relationships (BSRs), which describe the correlation between biodiversity and three-dimensional forest structure, have been used to map spatial patterns in biodiversity based on forest structural attributes derived from lidar. However, with the advent of spaceborne lidar like the Global Ecosystem Dynamics Investigation (GEDI), investigators are confronted with how to predict biodiversity from discrete GEDI footprints, sampled discontinuously across the Earth surface and often spatially offset from where diversity was measured in the field. In this study, we used National Ecological Observation Network data in a hierarchical modeling framework to assess how spatially-coincident BSRs (where field-observed taxonomic diversity measurements and structural data from airborne lidar coincide at a single plot) compare with BSRs based on statistical aggregates of proximate, but spatially-dispersed GEDI samples of structure. Despite substantial ecoregional variation, results confirm cross-biome consistency in the relationship between plant/tree alpha diversity and spatially-coincident lidar data, including structural data from outside the field plot where diversity was measured. Moreover, we found that generalized forest structural profiles derived from GEDI footprint aggregates were consistently related to tree alpha diversity, as well as cross-biome patterns in beta and gamma diversity. These findings suggest that characteristic forest structural profiles generated from aggregated GEDI footprints are effective for BSR diversity prediction without incorporation of more standard predictors of biodiversity like climate, topography, or optical reflectance. Cross-scale comparisons between airborne- and GEDI-derived structural profiles provide guidance for balancing scale-dependent trade-offs between spatial proximity and sample size for BSR-based prediction with GEDI gridded products. This study fills a critical gap in our understanding of how generalized forest structural attributes can be used to infer specific field-observed biodiversity patterns, including those not directly observable from remote sensing instruments. Moreover, it bolsters the empirical basis for global-scale biodiversity prediction with GEDI spaceborne lidar.

Role of data uncertainty when identifying important areas for biodiversity and carbon in boreal forests

Forest conservation plays a central role in meeting national and international biodiversity and climate targets. Biodiversity and carbon values within forests are often estimated with models, introducing uncertainty to decision making on which forest stands to protect. Here, we explore how uncertainties in forest variable estimates affect modelled biodiversity and carbon patterns, and how this in turn introduces variability in the selection of new protected areas. We find that both biodiversity and carbon patterns were sensitive to alterations in forest attributes. Uncertainty in features that were rare and/or had dissimilar distributions with other features introduced most variation to conservation plans. The most critical data uncertainty also depended on what fraction of the landscape was being protected. Forests of highest conservation value were more robust to data uncertainties than forests of lesser conservation value. Identifying critical sources of model uncertainty helps to effectively reduce errors in conservation decisions.

Global determinants of insect mitochondrial genetic diversity

Understanding global patterns of genetic diversity is essential for describing, monitoring, and preserving life on Earth. To date, efforts to map macrogenetic patterns have been restricted to vertebrates, which comprise only a small fraction of Earth’s biodiversity. Here, we construct a global map of predicted insect mitochondrial genetic diversity from cytochrome c oxidase subunit 1 sequences, derived from open data. We calculate the mitochondrial genetic diversity mean and genetic diversity evenness of insect assemblages across the globe, identify their environmental correlates, and make predictions of mitochondrial genetic diversity levels in unsampled areas based on environmental data. Using a large single-locus genetic dataset of over 2 million globally distributed and georeferenced mtDNA sequences, we find that mitochondrial genetic diversity evenness follows a quadratic latitudinal gradient peaking in the subtropics. Both mitochondrial genetic diversity mean and evenness positively correlate with seasonally hot temperatures, as well as climate stability since the last glacial maximum. Our models explain 27.9% and 24.0% of the observed variation in mitochondrial genetic diversity mean and evenness in insects, respectively, making an important step towards understanding global biodiversity patterns in the most diverse animal taxon.

Infectivity and stress tolerance traits affect community assembly of plant pathogenic fungi.

Understanding how ecological communities assemble is an urgent research priority. In this study, we used a community ecology approach to examine how ecological and evolutionary processes shape biodiversity patterns of plant pathogenic fungi, Fusarium graminearum and F. asiaticum. High-throughput screening revealed that the isolates had a wide range of phenotypic variation in stress tolerance traits. Net Relatedness Index (NRI) and Nearest Taxon Index (NTI) values were computed based on stress-tolerant distance matrices. Certain local regions exhibited positive values of NRI and NTI, indicating phenotypic clustering within the fungal communities. Competition assays of the pooled strains were conducted to investigate the cause of clustering. During stress conditions and wheat colonization, only a few strains dominated the fungal communities, resulting in reduced diversity. Overall, our findings support the modern coexistence theory that abiotic stress and competition lead to phenotypic similarities among coexisting organisms by excluding large, low-competitive clades. We suggest that agricultural environments and competition for host infection lead to locally clustered communities of plant pathogenic fungi in the field.

Reduced enumeration effort, but not coarse taxonomic resolution, is sufficient to represent beta diversity patterns of stream benthic diatoms

The use of reduced enumeration effort and coarse taxonomic resolutions are potential strategies for cost-effective biomonitoring programs and biological assessments. We evaluated whether reduced enumeration efforts (i.e., subsets of counted valves per sample) and identification to the genus level are sufficient to recover beta diversity patterns of benthic diatom metacommunities. Diatoms were sampled in 90 riffles within nine near-pristine subtropical streams. We found that reduced enumeration efforts were suitable to depict patterns both in the compositions of the communities and in biotic heterogeneity among streams produced by the original dataset (i.e., species-level identifications and 500 valves counted per riffle, the local community). A total of 400 and 50 valves were necessary to obtain similar compositional patterns observed using full samples identified at the species level for presence-absence and abundance data, respectively. Furthermore, biotic heterogeneity patterns among streams were recovered with 200 valves per local community for both presence-absence and abundance data. Identification to the genus level only reflected species-level compositional patterns when abundance data were used. However, the use of genus was not effective in depicting biotic heterogeneity patterns, independent of the enumeration effort. These results indicate that it is possible to reduce enumeration efforts, but not taxonomic resolution, to detect subtle regional biodiversity patterns of benthic diatoms in subtropical streams not subjected to strong environmental gradients. This is especially important due to the financial challenges faced by ecological and applied monitoring programs in tropical regions.

Contrasting results of multiple species delimitation approaches cause uncertainty in synecological studies: A case study on Sri Lankan chafers

Abstract Biodiversity patterns are the sum of multiple overlapping species distributions. Their analysis therefore requires proper species inference. DNA‐based species delimitation has become increasingly popular for such assessments, but their robustness is often problematic due to incongruence between multiple delimitation approaches. Here, we explored how contrasting results of different species’ delimitations translate into conclusions of synecological studies, exemplified by assemblages of phytophagous scarab beetles in Sri Lanka from different elevations and forest types. Particularly, we compared estimates based on complete assemblages and on cumulated species inventories inferred from individually analysed subclades. The patterns of assemblage similarity were analysed across different spatial scales with reference to morphospecies, molecular operational taxonomic units (MOTUs) and haplotypes. Method‐related ambiguity of species (MOTUs) estimates, which also included subclade inferences, severely affected the certainty of apparent biodiversity patterns at most spatial scales. Even more contrasting patterns resulted from individual clade‐wise analyses of faunal similarity or even from cumulated species inventories from individual clade‐wise species delimitation analysis. In this case study of tropical chafer beetles, haplotypes provided only very little explanatory information, since genetically highly diverse populations widely lacked shared haplotypes. Therefore, searching proper species boundaries should be the ultimate goal of biodiversity assessments to lend an enduring meaning to biodiversity research and its sustainable application. Our study underlines the need for awareness when synecological observations from different studies are integrated, which use different species delimitation methods for their biodiversity assessment, and its potential impact on conservation management.

Body size and life history shape the historical biogeography of tetrapods.

Dispersal across biogeographic barriers is a key process determining global patterns of biodiversity as it allows lineages to colonize and diversify in new realms. Here we demonstrate that past biogeographic dispersal events often depended on species' traits, by analysing 7,009 tetrapod species in 56 clades. Biogeographic models incorporating body size or life history accrued more statistical support than trait-independent models in 91% of clades. In these clades, dispersal rates increased by 28-32% for lineages with traits favouring successful biogeographic dispersal. Differences between clades in the effect magnitude of life history on dispersal rates are linked to the strength and type of biogeographic barriers and intra-clade trait variability. In many cases, large body sizes and fast life histories facilitate dispersal success. However, species with small bodies and/or slow life histories, or those with average traits, have an advantage in a minority of clades. Body size-dispersal relationships were related to a clade's average body size and life history strategy. These results provide important new insight into how traits have shaped the historical biogeography of tetrapod lineages and may impact present-day and future biogeographic dispersal.

Vertical variation in prokaryotic community composition and co-occurrence patterns in sediments of the Three Gorges Reservoir, China

Archaea and bacteria are distributed throughout the sediment; however, our understanding of their biodiversity patterns, community composition, and interactions is primarily limited to the surface horizons (0–20 cm). In this research, sediment samples were collected from three vertical sediment profiles (depths of 0–295 cm) in the Three Gorges Reservoir (TGR), one of the largest reservoirs in the world. Through 16S rRNA sequencing, it was shown that sediment microbial diversity did not significantly vary across the sediment. Nevertheless, a decline in the similarity of archaeal and bacterial communities over distance along sediment vertical profiles was noted. Nonmetric multidimensional scaling (NMDS) analysis revealed that archaeal and bacterial communities could be clearly separated into two groups, located in the upper sediments (0–135 cm) and deep sediments (155–295 cm). Meanwhile, at the fine-scale of the vertical section, noteworthy variations were observed in the relative abundance of prominent archaea (e.g., Euryarchaeota) and bacteria (e.g., Proteobacteria). The linear discriminant analysis effect size (LEfSe) demonstrated that twenty-four bacterial and twenty-six archaeal biomarker microbes exist in the upper and deep sediment layers. Each layer exhibited distinctive microbial divisions, suggesting that microbes with diverse biological functions are capable of thriving and propagating along the sediment profile. Co-occurrence network analysis further indicated that the microbial network in the upper sediments was more complex than that in the deep sediments. Additionally, the newly discovered anaerobic methanotrophic archaeon Candidatus Methanoperedens was identified as the most abundant keystone archaeal taxon in both sediment layers, highlighting the significance of methane oxidation in material cycling within the TGR ecosystem. In summary, our study examined the biodiversity and coexistence patterns of benthic microbial communities throughout the vertical sediment profile, providing detailed insights into the vertical geography of archaeal and bacterial communities in typical deep-water reservoir ecosystems.

Global Lepidoptera Index: Progress and Issues with Developing a Comprehensive Global Checklist of Moths and Butterflies

Lepidoptera (moths and butterflies) form one of the four largest animal orders, with published estimates that around 174,250 species had been described up to 2009 (Chapman 2009). Many species are conspicuous, charismatic and regularly recorded by citizen scientists. As a result, iNaturalist contains more than 15 million Lepidoptera observations (10.5% of all observations), and the Global Biodiversity Information Facility (GBIF) includes more than 83 million occurrence records for the group from all sources (3.5% of all biodiversity data and 9.8% of all non-bird data). A modern and comprehensive checklist of global moths and butterflies would therefore play a significant role in improving our ability to interpret biodiversity patterns and change. However, there is still no dataset that adequately covers the order, and good accessible digital checklists exist for a minority of families. The Global Lepidoptera Names Index (LepIndex) has served as the primary checklist for Lepidoptera used by Catalogue of Life (COL), the Global Biodiversity Information Facility (GBIF) and other global biodiversity informatics initiatives, with selected families sourced for other well-curated projects. LepIndex is the digitised version of a card index developed and maintained over decades at the Natural History Museum, London. Its intended purpose was to link published species names with the original literature references. LepIndex includes most names published prior to around 1985 (with some geographical bias) and additions for some groups up to around 1995. Since the card index was developed purely as a nomenclatural resource, no effort was made to track changes in generic placement and generally reflect taxonomic opinion from the time when each card was added. As a result, binomial combinations in LepIndex do not necessarily reflect either the original author's published binomial or contemporary classification. In superfamilies such as Gelechioidea and Noctuoidea, which have undergone significant reorganisation in the light of modern findings, many names are not associated even with the currently recognised family for the species. LepIndex has been migrated to TaxonWorks and is now maintained as the Global Lepidoptera Index (GLI), but addressing a shortfall of nearly 40 years of active taxonomy and fixing other legacy issues remains a major challenge. COL has recently worked with several groups of taxonomists to develop modern digital checklists for several families, but some groups can only practically be improved through edits to GLI. This presentation will summarise progress and metrics indicating the scale of the remaining task and the effort that will be required to maintain a comprehensive checklist that rapidly and accurates reflects new taxonomic findings.

Conservation of temporary streams: The relevance of spatiotemporal variation in beta diversity

Abstract Temporary streams are affected by increasing human alterations, and this situation is expected to worsen under global change. Understanding biodiversity trends and the contribution of sites and species to β‐diversity is of high importance in establishing conservation priorities at a regional scale. This paper focuses on aquatic macroinvertebrate biodiversity in temporary streams on the island of Mallorca, using a space–time framework. Differences in α‐diversity, spatial–temporal fluctuations of β‐diversity, local contribution to β‐diversity (LCBD) and species contribution to β‐diversity (SCBD) were examined. Data analysis shows that only the space–time approach to β‐diversity can capture the full variation of macroinvertebrate composition in temporary streams. This confirmed our hypothesis that β‐diversity patterns are better explained by incorporating the temporal dimension to the space–time approach. Regarding β‐diversity components, species replacement components always dominate over richness difference. These results imply that β‐diversity variability is mainly caused by differences in species composition, while the relative difference in richness among sites has a minor role. Consequently, the optimal conservation strategy requires the protection of several undisturbed sites. Although the LCBD analysis did not detect any keystone sites, it helped to identify those sites that should be prioritized for restoration efforts (sites with high LCBD values and low α‐diversity). We also concluded that SCBD analysis should be interpreted carefully, as rare endemic species had low SCBD values. This study demonstrated the need for incorporating temporal variability in the analysis of biodiversity patterns in highly dynamic ecosystems, such as temporary streams. It also revealed the urgency of preserving a spatial network of temporary streams under non‐impaired conditions that can act as dispersal point sources to other streams for biodiversity conservation. These insights are relevant for Mallorca and other Mediterranean islands, and for the protection of temporary rivers elsewhere.

Aviation and Climate Change: Challenges and the Way Forward

There is a broad scientific consensus that the phenomenon of global warming is very likely driving a global climate change. There is also a developing understanding that climate change and air transport have a two-way relationship. This paper aims to identify the possible impacts of climate change on the aviation sector and to discuss adaptation plans that will address the vulnerabilities and will ensure safe aviation-related operations. Climate change is known to cause disruptions in airport operations due to greater and more frequent temperature extremes and changes in precipitation and wind that are very possible to demand increased take-off distances and decreased climb rates. Extreme rainfall and rising sea levels may threaten coastal and low-lying airports with flooding. Changes in biodiversity and wildlife patterns intensify the bird strike hazard. Disruptions also occur in air operations. Increasingly frequent extreme weather events are responsible for air traffic delays. Changing atmospheric patterns and icing conditions challenge aircraft performance and rise flight duration and flight costs. The above risks may have a direct impact on travel and tourism, affecting destination favorability and the duration of the tourism season. All the above concerns call for urgent actions from the policymakers and the industry. Adaptation measures include the development of risk-assessment frameworks and action plans for the major stakeholders, technology advancements to deal with gas emissions and oil depletion, long-range infrastructure planning and investment, the introduction of climate-related regulations, as well as raising awareness and promoting collaboration as key steps in building climate change resilience for the global aviation sector.

Species diversity, trophic structure, and taxonomic distinctness of molluscan assemblages associated with Sargassum beds in a historically impacted bay

AbstractAnthropogenic impacts on coastal habitats can result in alterations of diversity parameters in marine invertebrate assemblages. Macroalgae beds are highly susceptible to human‐induced disturbances, supporting a great diversity of molluscan species and being ecologically important for coastal ecosystems. This study investigates the diversity alterations on Sargassum‐associated molluscan assemblages from areas with different distances from a main source of pollution within a historically impacted bay in Brazil. In general, sites closer to the pollution source presented lower species diversity, trophic diversity, and taxonomic relatedness among species. Beta diversity among assemblages was highly correlated with environmental differentiations among localities due to heavy metal concentrations in algal tissue. Bittiolum varium was the dominant species and was mainly responsible for differences in community parameters. Several trophic groups were well‐represented in Sargassum‐associated molluscan fauna, but assemblages were mostly dominated by micrograzers. A seasonal trend was observed in diversity alterations, with lower diversity during warm season at most sites except Santa Rita, possibly because it is the site less affected by human impacts. The importance of other environmental variables, such as hydrodynamism, for molluscan composition is also discussed. Our results highlight the potential of Sargassum‐associated molluscan assemblages for the study of impacted areas and reinforce the importance of using multiple community metrics to understand the biodiversity patterns of marine invertebrates under anthropogenic impacts.

Elevational microbial β diversity and community assembly processes in subarctic ponds

Abstract Knowledge about elevational β diversity patterns and processes is limited for microorganisms, especially in sensitive aquatic ecosystems at high latitudes. Our aim is to investigate elevational β diversity patterns and underlying assembly processes for three biofilm microbial groups in subarctic freshwater ponds. We sampled 89 ponds covering an elevational gradient from 10 to 1038 m above sea level in subarctic Finland and Norway. The microbial groups studied included benthic diatoms, cyanobacteria, and bacteria (i.e., bacteria other than cyanobacteria). We expected to find elevational distance decay in community similarity, driven primarily by variation in the local environment. We further tested whether the level of β diversity decreased towards higher elevations, and whether the relative influence of deterministic and stochastic processes on community assembly changed along the elevational gradient, with increasing effect of deterministic processes at higher elevations under more extreme environmental conditions. As statistical methods, we used generalised dissimilarity modelling, Mantel tests, and a null model with Raup–Crick dissimilarities. For all microbial groups, community dissimilarities increased with increasing environmental or elevational distances. The pure effects of environment were significant for all groups, and pH was the most important variable affecting community dissimilarities. Mean community dissimilarities generally decreased with elevation for all microbial groups. The communities were influenced by both deterministic and stochastic processes, the former of which was stronger towards higher elevations. The influence of deterministic processes was strongest for bacteria. Generally, the communities under deterministic control were more similar to each other than expected by chance. Elevational β diversity patterns of subarctic pond microorganisms primarily reflected environmental effects, showing decreasing β diversity towards high elevations owing to stronger environmental filtering. The relative effects of deterministic or stochastic assembly processes varied among microbial groups, highlighting the need for including multiple groups when studying biodiversity patterns and underlying ecological processes.

Plant invasion and fragmentation indirectly and contrastingly affect native plants and grassland arthropods

Plant invasion and habitat fragmentation have a detrimental effect on biodiversity in nearly all types of ecosystems. We compared the direct and indirect effects of the invasion of the common milkweed (Asclepias syriaca) on biodiversity patterns in different-sized Hungarian forest-steppe fragments. We assessed vegetation structure, measured temperature and soil moisture, and studied organisms with different ecological roles in invaded and non-invaded sites of fragments: plants, bees, butterflies, flower-visiting wasps, flies, true bugs, and spiders. Temperature and soil moisture were lower in invaded than in non-invaded area. Milkweed had a positive effect on plant species richness and flower abundance. In contrast, we mainly found indirect effects of invasion on arthropods through alteration of physical habitat characteristics and food resources. Pollinators were positively affected by native flowers, thus, milkweed indirectly supported pollinators. Similarly, we found higher species richness of herbivores in invaded sites than control sites, as species richness of true bugs also increased with increasing plant species richness. Predators were positively affected by complex vegetation structure, higher soil moisture and lower temperature. Furthermore, increasing fragment size had a strong negative effect on spider species richness of non-invaded sites, but no effect in invaded sites. Especially, grassland specialist spiders were more sensitive to fragment size than generalists, whereas generalist spider species rather profited from invasion. Although milkweed invades natural areas, we did not identify strong negative effects of its presence on the diversity of the grassland biota. However, the supportive effect of milkweed on a few generalist species homogenises the communities. The rate of invasion might increase with increasing fragmentation, therefore we recommend eliminating invasive plants from small habitat fragments to preserve the native biota. Focusing also on generalist species and revealing the indirect effects of invasions are essential for understanding the invasion mechanisms and would support restoration efforts.