The study was conducted in the limestone quarry near the village of Saskhori, southeast of Kaspi in Georgia’s Kartli Region. The quarry is owned by the Heidelberg Cement Company, and mining began in 2018. A survey conducted in 2018 before mining activities started had recorded 51 oribatid mite species across the area. The 2022 investigation repeated sampling across the quarry and adjacent landscapes to examine community composition, diversity, abundance and possible changes associated with anthropogenic disturbance.

Researchers collected soil in February, April and July 2022 from seven locations. The habitats included degraded steppe with rural and invasive plants, Mediterranean-type deciduous drought-resistant shrubbery, bare limestone bedrock, degraded xero-thermophilous oak forest, shrubland, an almond garden and mixed oak-hornbeam woodland and shrubbery. At each site, three 10-cubic-centimetre soil samples were randomly collected with a steel corer. In total, 63 samples were extracted for seven days in Berlese-Tullgren apparatuses, and the recovered material was preserved in 96% alcohol.

Specimens were mounted on temporary slides with lactic acid and identified microscopically. The analysis used taxonomic identification keys, rarefaction and extrapolation with 100 bootstrap replicates, and comparisons of species richness, individual density, Shannon diversity, Pielou evenness and Sørensen similarity. Neighbour-joining clustering based on Euclidean distance was also applied. The deposited specimens were assigned to the collection of the Institute of Zoology at Ilia State University in Tbilisi.

The survey yielded 983 mites representing 52 species, 41 genera and 28 families. Site Sa2, in Mediterranean-type deciduous drought-resistant shrubbery, had the highest richness, with 27 species, while Sa1, Sa4 and Sa7 each contained 22. Across habitat types, shrubbery was richest with 37 species, followed by the xero-thermophilous oak forest and mixed oak-hornbeam vegetation with 32. The almond garden’s rural and urban habitat contained 10 species, the lowest total recorded. Sa2 also had the largest number of individuals, with 191, followed by Sa1 with 185 and Sa3 with 175.

Xenillus tegeocranus was the most abundant species, with 120 specimens from six sites. Aleurodamaeus setosus had 106 specimens, Punctoribates punctum 85 and Ceratoppia bipilis 66, also across six of the seven sites. Seventeen species occurred at only one location. Shannon diversity was highest at Sa2, where H equalled 2.72, and lowest at Sa6, where H was 1.97 in Table 3. Pielou evenness ranged from 0.77 at Sa1 to 0.87 at Sa5 and Sa6. Sørensen-based clustering placed Sa1 with Sa2 and Sa3 with Sa4, while the Sa6 community was the most distinct from those in natural and semi-natural habitats.

Rarefaction and extrapolation indicated that additional sampling was likely to detect more species. The model estimated a maximum expected richness of 67 species, with an upper confidence limit of 88. Only 29 species, or 39% of the taxa reported in the two surveys, were shared between the 2018 and 2022 studies. The authors said the large difference in composition was probably driven more by incomplete sampling in both investigations than by faunal turnover over such a short interval. They also observed changes in relative abundance: several species found at one location in 2018 occurred at multiple sites in 2022, and Aleurodamaeus setosus and Punctoribates punctum joined Xenillus tegeocranus and Scheloribates laevigatus as broadly distributed species.

One taxonomic finding was the first Caucasus record of Liacarus oribatelloides, a species described in 1956 from the Czech Republic. Before the Saskhori finding, it had been reported from several Central European locations, including southern Germany, Austria, Italy, Slovakia, Poland, the Central Alps and the Tatra Mountains. The Saskhori specimens measured 1084–1198 micrometres in body length and 657–728 micrometres in width. They were distinguished from L. coracinus by their elongated, dark-brown to black body, strongly elongated lamellar cusp tips, a longer leg IV and a distinct inner tooth on the femur of leg IV.

The taxonomic status of L. oribatelloides remains uncertain. The latest world catalogue cited by the study treats it as a senior synonym of L. coracinus, while other publications have treated it as valid. The authors therefore stated that molecular genetic analysis is needed to clarify its status and interspecific boundaries within Liacarus. At the community level, the survey found lower mite density and diversity at heavily grazed sites where soil structure was destroyed, while more natural vegetation supported richer communities. The authors associated the observed community change most probably with ongoing limestone mining, but emphasized that the study’s extent and design do not permit predictions about future faunal changes.

Subject of Research: A 2022 field survey of oribatid mite species diversity, abundance and taxonomy across a Georgian limestone quarry and adjacent habitats.

Article Title: Soil mite ( Acari : Oribatida ) communities in the limestone quarry of Saskhori (Gerogia)

Article References: Arabuli, T., & Gogshelidze, M. (2023). Soil mite (Acari: Oribatida) communities in the limestone quarry of Saskhori (Gerogia). Caucasiana, 2, 189-197. https://doi.org/10.3897/caucasiana.2.e110495

Image Credits: AI Generated

DOI: 10.3897/caucasiana.2.e110495

Keywords: oribatid mites, soil biodiversity, Saskhori quarry, Georgia, habitat disturbance, limestone mining, species richness, ecological monitoring, Caucasus fauna, Liacarus oribatelloides, Soil, mite

The review was based on a Scopus search conducted on 6 November 2025 using terms related to invasive species and acoustic monitoring while excluding the non-invasive term. The search returned 143 papers, from which the researchers screened 44 potentially relevant abstracts and assessed their full texts. They retained 26 studies that directly examined passive acoustic monitoring of invasive animals.

The earliest study in the retained dataset was published in 2012, and the number of publications increased in more recent years. Amphibians accounted for 11 studies, birds and fish for five each, arthropods for three, and mammals and reptiles for one each. Research was concentrated in the USA and Australia, with fewer studies from Europe, Asia and South America and none identified from Africa. The geographic pattern partly reflected repeated studies of cane toads in Australia and barred owls in the USA.

The literature showed that acoustic monitoring was moving from exploratory sound characterization toward automated detection, machine learning, long-term monitoring and large-scale networks. Automated or semi-automated detection appeared in 17 of the 26 studies, and manual or expert validation was reported in 18, with four more using behavioural, experimental, laboratory or methodological validation. In amphibian studies, distinctive and relatively stereotyped mating calls supported automated identification. Other examples included deep-learning classifiers for cane toads, real-time monitoring of barred owls, acoustic classification of invasive fish and a model developed from 3,500 field-recorded common brushtail possum vocalizations in New Zealand.

For the case study, the researchers deployed 20 AudioMoth recorders at 11 water bodies in the Upper Rhine region. The devices were placed less than five metres from shorelines and programmed to record for 55 seconds every minute from two hours before sunset until three hours after sunset at a sampling frequency of 48 kHz. Simultaneous recordings covered 16 days from 13 to 29 June 2025, corresponding with the regional peak of bullfrog vocal activity and breeding season. Visual shoreline surveys were also conducted where possible, and all available iNaturalist records in the study region were compiled.

The 1,600 recorded hours were analysed with BirdNET Analyzer V2.4, which produced 56,298 three-second snippets identified as containing bullfrog calls. The researchers randomly selected 500 segments spanning confidence scores from 0.25 to 1.00 and assessed spectrograms and audio. Of these, 485 were judged correct and 15 incorrect. Logistic regression estimated that identifications with confidence scores above 0.703 had a 99% probability of being correct, with a 95% confidence interval for the threshold of 0.602 to 0.932.

Applying a multi-step classification process, the study classified 10 of the 20 recorders as having detected bullfrogs and thereby confirmed presence at five of the 11 monitored lakes. Recorders with more than 100 detections above the threshold were classified directly. For lower counts, the researchers examined the 15 highest-scoring detections; these were classified as positive if all exceeded the upper limit of the confidence interval, while uncertain cases were checked manually by listening to the audio. Tadpoles were observed at five sites, which were also the only sites with available citizen-science bullfrog records in the region.

Two lakes with confirmed bullfrog presence were within one kilometre of the protected nature reserves Altrhein Kleiner Bodensee and Altrhein-Königsee. The case study nevertheless has bounded scope: it covered one 16-day recording period, 11 lakes and two confirmed presence locations, and failure to confirm calls at the other lakes did not establish that bullfrogs were absent. Detection also depended on animals vocalizing during the deployment period. Across the broader literature, suitability varied among taxa, with acoustic monitoring most applicable to species producing frequent, distinctive and predictable sounds and less comprehensive for weakly vocal or non-vocal animals.

The authors concluded that passive acoustic monitoring has strong potential to support repeated and scalable invasive-species surveillance, particularly when automated identification is paired with transparent validation, defined thresholds, manual checks and integration with visual surveys and citizen science. It can help confirm persistence at known sites, identify likely breeding activity through repeated mating calls and prioritize follow-up in areas with limited resources. The review did not establish a uniform detection rate across species or environments, and the case study demonstrates feasibility rather than a comprehensive estimate of monitoring accuracy across all invasive animals.

Subject of Research: Evaluation of passive acoustic monitoring for detecting invasive animal species through literature synthesis and an American bullfrog field case study.

Article Title: Passive acoustic monitoring as a tool for early detection of invasive animal species: a systematic review and a case study

Article References: Becker, D., Kasten, M. K., Weber, T., Grass, I., & Hiller, T. (2026). Passive acoustic monitoring as a tool for early detection of invasive animal species: a systematic review and a case study. Environmental Monitoring and Assessment, 198(9), Article 1003. https://doi.org/10.1007/s10661-026-15873-2

Image Credits: AI Generated

DOI: 10.1007/s10661-026-15873-2

Keywords: passive acoustic monitoring, invasive species, American bullfrog, automated species detection, BirdNET, AudioMoth, systematic review, early detection, biodiversity monitoring, Passive, acoustic, monitoring

The review evaluates evidence across four hierarchical scales: material and surface, module and geometry, reef and site, and implementation and system. According to the abstract, overall performance depends on interactions among material formulation, geometric configuration, manufacturing process, site-specific conditions, and decision-making across scales. The review also reports persistent gaps between ecological objectives, material and manufacturing qualification, physical performance assessment, and long-term monitoring.

Translating bioinspired features into usable metrics requires information on chemical stability, degradation behavior, biological response, and durability. Manufacturing processes must retain intended surfaces, cavities, porosity, and structural attributes. Although hydrodynamic and structural models can support design decisions, their predictive value depends on model assumptions, material characterization, experimental validation, and field conditions. The framework therefore connects restoration objectives to design, qualification, multiphysics assessment, validation, and adaptive implementation.

The available evidence indicates that a single aspect cannot establish the suitability of an artificial reef design for ecological restoration. Instead, candidate structures require coordinated assessment of materials, geometry, fabrication, physical performance, environmental setting, biological outcomes, and implementation. The published item is a review and framework proposal; it does not report a new field trial, controlled experiment, or measured restoration effect. The supplied abstract also does not provide quantitative performance results, specific test systems, or long-term ecological outcomes, so the approach remains a synthesis intended to guide evaluation and further development of artificial reef infrastructure.

Subject of Research: A review framework for evaluating bioinspired additively manufactured artificial reefs in coral restoration.

Article Title: A multiscale framework for bioinspired additively manufactured artificial reefs in coral restoration

Article References: Vásquez Trejos, E. M., Ortega Del Rosario, M. D. L. Á., & Weeks Santos, S. (2026). A multiscale framework for bioinspired additively manufactured artificial reefs in coral restoration. Discover Sustainability. https://doi.org/10.1007/s43621-026-05048-x

Image Credits: AI Generated

DOI: 10.1007/s43621-026-05048-x

Keywords: coral restoration, artificial reefs, additive manufacturing, bioinspired design, multiscale framework, materials compatibility, multiphysics performance, ecological monitoring, multiscale, framework, bioinspired, additively

The research combined environmental sampling with taxonomic identification and statistical analysis of surface-active soil invertebrates collected in eight gallery-forest sites within the 10,500-hectare ecological station in the Federal District. Each 100-square-metre sampling unit contained 10 pitfall traps, whose combined catches formed one composite sample. Traps were deployed from May through July 2021 and collected weekly during seven campaigns. The organisms were identified, counted, measured, freeze-dried and homogenised, while soil and litter were collected from the centre of each sampling unit. Total mercury was measured by atomic absorption spectrometry, with certified reference materials used to verify analytical accuracy and recovery rates of 81% to 103%.

Mercury was significantly more concentrated in litter than in soil, a difference associated with paired statistical testing that yielded t = 4.402, seven degrees of freedom and p = 0.0032. The authors regarded the forest canopy as a plausible interception surface for atmospheric mercury, allowing mercury captured by vegetation to enter the soil compartment through litterfall. Sampling took place in gallery forests, a Cerrado formation that follows watercourses. Their dense canopies limit direct deposition to the ground, while prolonged leaf exposure, reduced litter leaching and shelter from sunlight can help retain deposited mercury. These mechanisms are consistent with the observed litter enrichment, but the comparison does not by itself identify the precise source or chemical pathway responsible.

Soil organic matter was a significant predictor of mercury concentration, accounting for 45.5% of the observed variation in the regression analysis, with p = 0.039. The estimated slope indicated that soil mercury increased by 0.537 units for each unit increase in organic matter content. Soil pH showed no significant relationship with total mercury. The authors connected the organic-matter association with mercury’s affinity for sulfur-bearing functional groups, including thiol and disulfide sites, which can promote binding of inorganic mercury in soil. They also noted that litter decomposition can transfer captured mercury into the underlying soil. Because only eight paired sampling units supplied the environmental comparison, the regression and soil–litter contrast should be interpreted within the scope of this small, site-specific field survey.

The invertebrate collections spanned 15 orders and included ants, termites, spiders, scorpions, beetles, flies, wasps, crickets and other epigeic fauna. Among orders with enough observations for comparison, termites had the highest mean mercury concentration at 458.11 ± 357.9 nanograms per gram, followed by scorpions at 457.48 ± 264.06 nanograms per gram and spiders at 340.70 ± 184.72 nanograms per gram. Variation was often substantial: for several groups, including harvestmen, flies, Vespidae wasps and ants, the standard deviation exceeded the mean. These broad spreads may reflect genuine differences among taxa, but the study’s relatively coarse taxonomic resolution, together with the analysis of whole animals without prior removal of gut contents, likely added variability.

Bioaccumulation factors were calculated by comparing mercury in each organism with its dry-weight concentration in soil or litter. A factor below 1 was classified as no significant bioaccumulation, 1 to 2 as microaccumulation, and above 2 as macroaccumulation. Overall, 83.75% of the analysed samples had a bioaccumulation factor of at least 1 relative to soil, and 91.4% of those accumulators met that threshold relative to litter. Among samples showing accumulation potential, 80.38% were macroaccumulators when compared with soil and 68.53% when compared with litter. Spiders were macroaccumulators in both comparisons, while ants showed a stronger tendency to exceed the macroaccumulation threshold relative to soil than to litter. The divergence between the two reference compartments reinforces that the surrounding soil may be an important exposure pathway for some animals.

Four mercury concentration classes were then compared with the feeding habits assigned to the organisms. Predator frequency rose from 9.1% in the lowest class, no more than 43.50 nanograms per gram, to 30.1% in the next class, 38.1% in the third and 45.5% in the highest class, above 273.81 nanograms per gram. Phytophagous organisms moved in the opposite direction, declining from 26.1% of the lowest class to 15.0%, 8.2% and 2.3% across the progressively higher classes. Omnivores predominated in the second group, while necrophagous organisms were proportionally more frequent in the highest. This shift is consistent with mercury transfer through feeding relationships, particularly the ingestion of contaminated prey, but the study characterized the inference as a local trophic-network pattern rather than a direct measurement of every trophic pathway.

Multivariate analysis provided additional support for an association between ecological function and mercury burden. The analysis combined organism mercury concentration, the bioaccumulation factor based on litter and mean body size. The first two discriminant functions explained 96.69% of the separation among feeding groups, and their profiles differed significantly at p < 0.0001. Xylophagous and sap-sucking organisms occupied similar positions, whereas detritivores, necrophages, parasitoids and predators showed partially overlapping profiles. Predatory and omnivorous groups lay closer to the centre. The overlap demonstrates that organisms with broadly similar feeding strategies did not all accumulate identical amounts of mercury, indicating that diet is not the only relevant variable. Exposure through soil contact, habitat use, body size, taxonomy and other physiological or ecological traits may also influence tissue concentrations.

The authors identified several important limitations, including the inability to identify many specimens to genus or species, large within-group variation and possible contributions from undigested material in whole-body samples. They recommended species-level identification and gastrointestinal depuration in future work. The study also took place in gallery forests inside a peri-urban reserve bordered by urban and agricultural landscapes, where previous research found elevated mercury near roads and attributed it to traffic-related emissions. Regional atmospheric deposition, wildfires and natural geological contributions are also plausible influences on the reserve’s mercury cycle. Accordingly, the findings describe bioaccumulation and patterns consistent with biomagnification in one Brazilian savanna system; they do not establish clinical effects in people, prove a specific mercury source or show that the same concentration gradients occur throughout the Cerrado. Nevertheless, the data demonstrate how litter, soil properties, organism–environment contact and feeding relationships can jointly structure terrestrial mercury transfer in a relatively under-studied soil food web.

Subject of Research: Terrestrial mercury bioaccumulation and trophic transfer in Brazilian Cerrado soil invertebrates

Article Title: Mercury dynamics in surface-active soil invertebrates from an ecological reserve in the Brazilian savanna

Article References: Fernandes, I. O., Monteiro, L. C., de Miranda, V. L., de Souza, J. P. R., Rodrigues, Y. O. S., de Castro Paes, É., Júnior, W. F. A., & Bernardi, J. V. E. (2026). Mercury dynamics in surface-active soil invertebrates from an ecological reserve in the Brazilian savanna. Environmental Monitoring and Assessment, 198(11), Article 1230. https://doi.org/10.1007/s10661-026-16051-0

Image Credits: AI Generated

DOI: 10.1007/s10661-026-16051-0

Keywords: mercury, bioaccumulation, biomagnification, soil invertebrates, Brazilian Cerrado, terrestrial food webs, leaf litter, soil contamination, ecological monitoring, dynamics, surface-active, soil

The review considered publications applying DNA metabarcoding to terrestrial arthropods, including whole-organism community samples, tissue, pollen, gut contents, faeces and environmental DNA. It covered research on species-richness assessments, pollen analysis and food-web studies, excluding individual DNA barcoding, PCR-free methods and long-read sequencing. The literature search was conducted in Google Scholar and EBSCO Discovery Service on 17 January 2022 using terms combining quantitative searches, insects and metabarcoding, and additional eligible studies were included based on the authors’ expertise.

The authors extracted information about study type, sample type, species group, methods and parameters, then assessed whether each approach could support numbers of individuals, relative abundance or biomass while considering additional equipment, cost and labor. This scope means the conclusions concern methodological options identified in the reviewed literature rather than a new experiment or a universal validation of terrestrial arthropod monitoring. The need for faster and broader monitoring is linked to well-documented declines in arthropods and the limits of traditional identification.

Sorting trap catches and identifying specimens by morphology are costly, time-consuming and dependent on taxonomic expertise that is in short supply. DNA metabarcoding can raise sample throughput by automating laboratory and bioinformatic workflows, and it may resolve cryptic species, reveal intraspecific genetic diversity and permit the study of non-invasively collected material such as faeces. It can also detect pollen and prey or predator DNA, making it useful for examining pollination and food-web interactions.

Yet implementation in policy monitoring has been constrained by skepticism among taxonomists, missing expertise and infrastructure, non-standard molecular protocols, incomplete reference databases and the destruction of specimens during DNA extraction. The quantitative interpretation of sequence data remains a central obstacle. A read count is not an individual count.

PCR then introduces taxon-specific distortion because primers bind with different efficiencies, with mismatches near the 3′ end of a primer potentially having a strong effect. Other influences include variation in target-marker GC content, amplicon length and marker-gene copy number, as well as stochastic processes during amplification and sequencing and filtering decisions during bioinformatic processing. Sample complexity can also affect how much sequence is recovered.

A meta-analysis of 22 metabarcoding studies found a weak relationship between biomass and read counts, accompanied by large uncertainty. Because those studies used different protocols, organisms and sample types, their results are not directly comparable, but the analysis supports the central conclusion that raw read counts are unsuitable as stand-alone abundance estimates. Several semi-quantitative metrics are widely used despite their limitations.

Frequency or percentage of occurrence reduces sequence data to presence and absence across samples. Bipartite network analyses use the presence of taxa to represent interactions, while relative read abundance, rarefaction, logarithmic or rank transformation, and related transformations retain different aspects of the read-count table. These measures can reveal community composition and are often informative for pollen, faecal, gut-content and whole-organism samples.

Their calculation is straightforward, but factors from extraction through PCR and sequencing mean that they generally cannot support defensible estimates of the number or weight of organisms. The review therefore distinguishes the absolute number of individuals belonging to a species from its proportional representation in a sample and treats biomass, the weight of those individuals, as a separate quantity. Correction factors offer a more direct attempt to reduce read-abundance bias.

One method processes artificial mock communities of known composition alongside environmental samples, measures how each taxon is represented and uses the result to adjust reads from samples of unknown composition. This can improve abundance estimates where taxa in the mock community also occur in the field samples, a restriction that is substantial for hyperdiverse arthropod catches containing many taxa. Correction factors may also be extended to close relatives when similar primer-related skews are assumed, and one beetle study found strong phylogenetic signals in primer-template mismatches.

An alternative iterative approach begins with randomized correction factors, calculates predicted specimen counts from sequence data, compares those predictions with counts from morphologically identified specimens and repeatedly revises the factors until the two sets converge. This method has produced predicted individual counts that correlated highly with actual counts, but it requires high-quality reference material, concordant morphological and molecular identifications, and substantially more time and expense. Correction factors can also fluctuate when PCR conditions change, and community evenness, copy-number variation and differences in DNA quality can remain uncorrected.

Spike-ins, also called internal standards, offer a comparatively simple way to improve comparisons among samples. A defined amount of reference DNA is added to every sample, preferably after tissue lysis but before extraction, so that it is co-extracted, co-amplified and co-sequenced with the sample. The reference can be tissue, genomic DNA, pre-amplified DNA, a plasmid or synthetic DNA, provided that it contains suitable primer-binding sites and is represented in the reference database.

Dividing the reads assigned to each amplicon sequence variant by the reads assigned to the spike-in can correct for differences in sequencing depth between samples. Studies reviewed by the authors reported improved within-species abundance comparisons, and the method has potential for biomass estimation. It requires little additional laboratory effort and can be used across sample types, but it does not correct biases among species within an individual sample.

The literature reviewed did not systematically resolve the likely roles of sample complexity and taxon-specific primer efficiency in that limitation. Primer design and the use of multiple loci can improve taxon recovery and lessen some distortions, but neither provides a general solution to counting. Primer sets must be universal enough to cover the organisms of interest, generate fragments suitable for the sequencing platform and permit species-level identification.

Their performance should therefore be validated with complex mock communities, because over- and under-amplification of entire arthropod lineages or dominant plant taxa in pollen can distort read abundance. Multi-locus metabarcoding uses markers with different taxonomic biases, including COI and ribosomal or chloroplast regions, and has been applied to whole-organism, tissue, pollen, faecal, gut-content, soil and environmental-DNA samples. Summarizing rank order or median proportional abundance across loci can reduce the influence of any one marker.

Separate PCRs and analyses, however, increase cost and labor, while multiplexing may introduce competition among primer sets. Loci often recover discordant species lists because of different amplification efficiencies and gaps in reference databases. Such lists can broaden coverage, but abundance estimates are generally limited to taxa detected by more than one marker.

The review’s most promising current combination for whole-organism community samples is to photograph and process specimens individually, then recombine selected material for mixed-sample sequencing. Photography records the number of organisms and permits body-size measurements that can support biomass estimates, while metabarcoding supplies species-level identifications that may be difficult to obtain from images alone. Handling specimens separately also makes it possible to remove or sample body parts for DNA extraction rather than necessarily destroying an entire voucher, and the images provide a permanent reference for later checks.

The approach is exceptionally labor-intensive, but automated imaging and machine-learning-based recognition are emerging as ways to improve efficiency. Researchers could combine individually processed specimens into pseudo-communities to retain cost-efficient metabarcoding while linking sequence results to counts and measurements. A related strategy weighs whole-organism samples, uses flow cytometry for pollen or applies quantitative or digital droplet PCR, although each additional method has restrictions on the samples with which it can be combined.

A comprehensive workflow would pair direct specimen information with calibrated molecular data rather than treat any one correction as sufficient. Specimens can be photographed, counted, measured and weighed, with a standardized spike-in added before extraction. The resulting amplicon sequence-variant table provides taxonomic assignments, and image-derived counts, body measurements and biomass estimates can then be assembled with the molecular results.

Positive controls such as mock communities, negative controls, biological replicates and technical replicates are recommended alongside evaluation of primer performance. The additional costs and labor may be justified by improved data, although limited monitoring budgets can make technical replication difficult. Environmental DNA is more demanding because DNA persistence and transport depend on environmental conditions, sampling and the cellular or molecular state of the material.

For that application, the review regards presence and occurrence data, occupancy models and experimental designs that support indirect counts as more defensible than individual abundance estimates. Future approaches include unique molecular identifiers, Bayesian and occupancy models, tracer approaches, decay corrections and PCR-free mitochondrial or nuclear sequencing. Unique molecular identifiers label DNA fragments before amplification, allowing the number of original template copies represented by a sequence variant to be estimated.

Occupancy models can account for false negatives, while Bayesian models can incorporate primer choice and other workflow parameters. PCR-free approaches avoid amplification-related bias, but incomplete reference genomes, extraction bias, variable gene copy number, computational demands and data-storage requirements constrain their use. The review’s broader conclusion is that DNA metabarcoding should complement rather than replace morphological monitoring.

It can efficiently expand the species coverage, detect sensitive trends and support pollen and food-web analyses, but reliable counts and biomass currently require calibrated controls, suitable correction methods and direct specimen-level measurements rather than interpretation of raw reads alone.

Subject of Research: Methods for estimating terrestrial arthropod abundance and biomass with DNA metabarcoding

Article Title: Abundance estimation with DNA metabarcoding – recent advancements for terrestrial arthropods

Article References: Sickel, W., Zizka, V., Scherges, A., Bourlat, S. J., & Dieker, P. (2023). Abundance estimation with DNA metabarcoding – recent advancements for terrestrial arthropods. Metabarcoding and Metagenomics, 7, Article e112290. https://doi.org/10.3897/mbmg.7.112290

Image Credits: AI Generated

DOI: 10.3897/mbmg.7.112290

Keywords: DNA metabarcoding, terrestrial arthropods, abundance estimation, biomass estimation, arthropod monitoring, spike-ins, mock communities, primer bias, environmental DNA, ecological monitoring, Abundance, estimation

Researchers conducted systematic field surveys and long-term in situ monitoring at the type locality of Boulenophrys elongata, located on Mt. Lianhua in Huidong County, Guangdong Province. The study area, situated at elevations between 700 and 1000 meters above sea level, features flowing montane streams and nearby forest floors within subtropical evergreen broad-leaved forests. By collecting five adult individuals during the breeding season, the team enabled the supplementation of morphological diagnoses and the establishment of baseline ecological data. These specimens, including three adult males and two adult females, were fixed in 10% buffered formalin and later transferred to 70% ethanol for detailed examination. The collection of these breeding individuals was crucial for clarifying the sexual dimorphism that had remained insufficiently clarified in previous studies, providing the first empirical support for population assessments and conservation strategies for this montane amphibian.

The morphological analysis revealed distinct sexual dimorphism that was absent in the original type series. Adult males measured between 27.8 and 30.2 mm in snout-vent length, while adult females ranged from 34.6 to 37.6 mm. Breeding males exhibited a nuptial pad with dense black nuptial spines at the bases of fingers I and II, a subgular vocal sac, and dense tiny conical spines on their dorsum. These traits, combined with the presence of vomerine ridges and teeth, and a well-developed canthus rostralis, helped refine the morphological diagnosis of the species. The dorsal skin was relatively smooth with dense granules and a weak discontinuous X-shaped ridge on the center of the dorsum, while the limbs featured discontinuous transverse ridges and tubercles. This detailed characterization resolves taxonomic ambiguity and provides a clearer framework for identifying the species in the field, distinguishing it from other members of the genus that often exhibit similar external features but differ in subtle reproductive traits.

Ecological observations indicated that Boulenophrys elongata is strictly associated with flowing montane streams and the adjacent forest floor. The breeding season appears to span from early March to late August, with reproductive activities triggered exclusively by heavy rainfall. Male advertisement calls were recorded during this period, but they ceased if rainfall stopped for several successive days, even under high ambient humidity. This dependence on specific weather conditions highlights the vulnerability of the species to climate variability and habitat fragmentation. The toads inhabit a microhabitat characterized by intricate narrow rock formations and dense shrubs, which provide shelter and breeding sites. Understanding these ecological traits is essential for conservation efforts, as the narrow range and specific habitat requirements make Boulenophrys elongata particularly susceptible to environmental changes and anthropogenic disturbances in the montane regions of southern China.

One of the most significant findings of this study is the first formal documentation of pre-amplexus reproductive behavior in the genus Boulenophrys. Continuous observation of the courtship behavior was carried out for 56 minutes on March 28, 2026, under minimal field disturbance. The sequence began with males establishing calling territories on riparian shrub foliage at approximately 25 cm above the ground. They produced intermittent quack-like advertisement calls via a single subgular vocal sac to attract conspecific females and defend their home ranges. The female, initially stretching its body forward on leaves, adjusted its orientation and crawled towards the male after detecting the calls. This initial interaction set the stage for a complex series of behavioral exchanges that demonstrated the intricate nature of mating strategies in this species.

The courtship process involved several distinct stages, including mutual behavioral recognition and positional adjustment. The male and female engaged in reciprocal blinking responses, which served as typical interactive cues during the assessment phase. The male would cease calling when the female blinked or turned its head, indicating a sensitive response to visual signals from the female. Physical contact occurred when the male touched the posterior margin of the female’s snout with its snout tip and rubbed the digits of the female’s fore-limb with its snout and eyelids. This tactile stimulation, accompanied by vocal signals and blinking, highlighted the multi-modal nature of communication between the sexes. The female’s responses, including head tilts and short jumps, played a crucial role in the progression of the courtship sequence, demonstrating a dynamic interaction that was previously undocumented in the genus.

Following the initial physical contact, the male shifted to a companion-leading courtship strategy, guiding the female towards potential breeding microhabitats. The male crawled steadily towards the direction of the advertisement calls, while the female followed by alternating crawling and jumping. The pair maintained close proximity, with seven intermittent physical contacts occurring throughout the movement. When separated, the male produced calls to re-orientate the female, who responded with a single blink after relocating the male. This guided movement led the pair towards a seepage area concealed within rock crevices, approximately 12 meters away. The observation ended before amplexus could be observed, but the detailed recording of the pre-copulatory sequence provided valuable insights into the mating behavior of Boulenophrys elongata and the broader genus.

The study underscores the importance of sustained field surveys and long-term monitoring for effective anuran conservation. The observed behavioral patterns, including male calling, female assessment, snout contact, and male-led guiding, suggest complex reproductive adaptations in fragmented montane habitats. However, limitations such as interrupted observations due to dense vegetation and rugged terrain, and the restriction to a single recorded event, highlight the need for repeated observations to confirm the consistency and generality of these patterns. The findings provide a comparative framework for behavioral evolution and phylogenetic studies within the genus, emphasizing the value of targeted fieldwork in unraveling the diversified reproductive behavior of Boulenophrys species. This research not only resolves taxonomic ambiguities but also establishes a baseline for future conservation assessments and population monitoring of this narrow-range endemic species.

Subject of Research: Reproductive behavior and sexual dimorphism in Boulenophrys elongata

Article Title: Supplementary description of Boulenophrys elongata ( Anura , Megophryidae ): Sexual dimorphism and observations on reproductive behaviours

Article References: Wang, J., Zhan, B.-B., Tan, L., Xiao, W.-W., Li, Y.-H., Lin, S.-S., & Zeng, Z.-C. (2026). Supplementary description of Boulenophrys elongata (Anura, Megophryidae): Sexual dimorphism and observations on reproductive behaviours. Biodiversity Data Journal, 14, Article e201422. https://doi.org/10.3897/bdj.14.e201422

Image Credits: AI Generated

DOI: 10.3897/BDJ.14.e201422

Keywords: Boulenophrys elongata, sexual dimorphism, reproductive behavior, amphibian conservation, montane streams, courtship ritual, herpetology, Guangdong, horned toads, ecological monitoring, Supplementary, description

The research, conducted by Tamil Selvan Gurunathan and Aryya Gangopadhyay of the Department of Information Systems at the University of Maryland Baltimore County, addresses a fundamental tension in autonomous ecological monitoring. Classical coverage path planning algorithms, including boustrophedon decomposition, spiral traversal, and space-filling curve methods, generate deterministic trajectories that achieve complete coverage with minimal overlap, but only when the environment is static and fully known in advance. When obstacles change, new terrain features appear, or environmental uncertainty enters the picture, precomputed paths become suboptimal or infeasible, forcing expensive replanning or centralized coordination. Reinforcement learning offers the opposite trade-off: robots learn navigation policies directly from interaction with the environment, adapting to unforeseen changes using only local observations, but coverage tasks provide sparse and delayed rewards that make efficient exploration notoriously difficult during training.

The core insight of the new work is that these two paradigms need not be rivals. Rather than replacing reinforcement learning with predetermined trajectories, the researchers treat the Hilbert space-filling curve as a geometric prior, a structured exploration scaffold that biases early learning toward locality-preserving traversal while leaving the learned policy free to deviate whenever accumulated experience indicates that alternative actions produce higher long-term reward. The Hilbert curve possesses a property that makes it uniquely suited to this role: its recursive construction ensures that consecutive indices in the one-dimensional ordering correspond, whenever possible, to spatially adjacent cells in the two-dimensional workspace. This locality preservation minimizes long-distance transitions and naturally produces coherent traversal patterns across multiple spatial scales, unlike simpler alternatives such as Morton Z-order curves or row-major traversals.

Technically, the framework operates through three complementary mechanisms. First, each robot’s current grid position is converted into a normalized Hilbert index using only integer arithmetic, and this single scalar is concatenated with the robot’s local egocentric occupancy map to produce an augmented state, increasing observation dimensionality by just one feature. Second, during training, with a probability that is gradually annealed throughout learning, the robot selects the action that advances it toward the next reachable Hilbert cell rather than sampling from its stochastic policy. Third, potential-based reward shaping is applied, where the modified reward preserves the optimal policy under the original Markov Decision Process while encouraging progression along locality-preserving traversal sequences during early learning. Crucially, the underlying optimization procedures of both Deep Q-Networks and Proximal Policy Optimization remain completely unchanged; the framework modifies only the observation representation, exploration strategy, and reward computation, introducing negligible computational overhead.

The experimental evaluation was extensive. Simulation studies were conducted in discrete two-dimensional occupancy-grid environments of two workspace sizes, with procedurally generated terrain constraints representing features such as dense vegetation, mature trees, rock outcrops, wetlands, streams, and protected habitat zones. Teams of 4, 8, 12, and 16 homogeneous robots were deployed, each operating independently with only local observations and no explicit inter-robot communication. All models were implemented in PyTorch, trained with the Adam optimizer for 300,000 interaction steps, and evaluated across five independent training runs with different random seeds, with statistical comparisons performed using Welch’s two-sample t-test and 95 percent confidence intervals.

The results are striking. With sixteen robots, the average coverage ratio increased from 0.589 for standard DQN to 0.895 for the Hilbert-augmented variant, and from 0.683 for standard PPO to 0.927 for the augmented version. Redundancy, measured as visits per unique cell, dropped from 4.173 to 1.948 for DQN-based methods and from 3.354 to 1.768 for PPO-based methods at the same team size. The Hilbert-augmented methods accumulated reward more rapidly throughout training and satisfied a stability-based convergence criterion, requiring the rolling average reward to remain above 90 percent of the maximum observed reward for ten consecutive evaluation windows, using fewer interaction steps than conventional baselines. All reported coverage and redundancy improvements were statistically significant.

Ablation studies revealed which component matters most. Removing the curve-guided exploration bias produced the largest performance collapse, dropping coverage to levels comparable with baseline PPO while substantially increasing redundancy. Removing Hilbert-based state augmentation, by contrast, produced only small changes within one standard deviation of the complete framework, and removing reward shaping yielded intermediate results. This pattern indicates that the principal benefit arises from structured exploration rather than from the inclusion of the Hilbert index as an additional state feature, though the reduced variability across repeated training runs suggests that state augmentation contributes to learning stability during later optimization stages.

The hardware validation is what elevates this work from simulation to field robotics. Policies trained entirely in simulation were deployed on two Boston Dynamics Spot quadruped robots operating in an outdoor environment containing trees, shrubs, bushes, uneven ground, and other natural vegetation. Policy-generated survey trajectories were converted into executable planar trajectories through a waypoint interface built on the Spot SDK, maintaining lease management, time synchronization, emergency stop protection, and obstacle safety constraints. In field trials, the Hilbert-augmented PPO completed missions 31.9 percent faster than standard PPO, reduced redundancy by 51.6 percent, improved coverage efficiency from 76.4 to 94.1 percent, and lowered path-following error from 0.19 to 0.08 meters, achieving a 100 percent trial success rate compared with 66.7 percent for the baseline.

The practical implications extend across environmental science. Autonomous ecological monitoring requires repeated coverage of forests, wetlands, grasslands, coastal ecosystems, and restoration sites for applications including biodiversity assessment, vegetation mapping, soil monitoring, invasive species detection, and post-restoration evaluation. Because the framework is independent of sensing modality, it can be integrated with RGB cameras, multispectral and hyperspectral imagers, thermal cameras, LiDAR, and environmental sensing payloads. The reduction in redundant traversal directly translates to longer battery life, reduced mechanical wear, and more unique sampling locations per deployment, while the absence of explicit inter-robot communication makes the approach suitable for large natural environments where connectivity is intermittent or unavailable.

The authors acknowledge limitations, including the absence of explicit cooperative planning, the use of occupancy-grid abstractions that do not model heterogeneous terrain traversability or seasonal changes, and the limited scale of hardware validation with only two robots. Future work includes evaluating alternative geometric priors such as Morton and Peano curves, integrating with modern multi-agent reinforcement learning algorithms including MAPPO and QMIX, and deploying larger heterogeneous teams of ground, aerial, and aquatic platforms. But the central contribution stands: lightweight locality-preserving geometric priors, computable with simple integer arithmetic and a single additional scalar, can substantially improve the exploration process that underlies reinforcement learning, combining the systematic spatial organization of classical coverage planning with the adaptability of learned policies.

Subject of Research: Robotics

Article Title: Geometric priors for reinforcement learning-based multi-robot ecological monitoring

Article References: Gurunathan, T. S., & Gangopadhyay, A. (2026). Geometric priors for reinforcement learning-based multi-robot ecological monitoring. Frontiers in Robotics and AI, 13, Article 1934273. https://doi.org/10.3389/frobt.2026.1934273

Image Credits: AI Generated

DOI: 10.3389/frobt.2026.1934273

Keywords: reinforcement learning, Hilbert curves, multi-robot systems, ecological monitoring, Boston Dynamics Spot, coverage path planning, DQN, PPO, Geometric, priors, reinforcement, learning-based

Yet behind this rapid ascent lies a persistent problem that threatens to undermine the field’s credibility: inconsistency. Different laboratories use different protocols for collecting, filtering, preserving, extracting, and sequencing eDNA. Different studies apply different quality-control measures, different bioinformatic pipelines, and different reporting conventions. The result is a patchwork of methods whose outputs cannot always be meaningfully compared across studies, laboratories, or jurisdictions. For a technique whose greatest promise lies in large-scale, long-term, and cross-border biodiversity monitoring, this fragmentation is more than an inconvenience — it is a structural barrier to adoption. Regulatory agencies, which ultimately decide whether eDNA data can inform environmental assessments and compliance decisions, have been hesitant to rely on results that lack internationally recognized standards backing them up.

This challenge is now being confronted head-on. In a perspective article published in the journal Metabarcoding and Metagenomics, a team of twenty-five leading eDNA researchers from around the world announced the launch of the International eDNA Standardization Task Force, or iESTF. The initiative, described in a paper led by Mehrdad Hajibabaei of the University of Guelph alongside Florian Leese, Cathryn Abbott, Hitoshi Araki, Donald J. Baird, Pedro Beja, Kristy Deiner, Hideyuki Doi, and many other prominent figures in the field, aims to facilitate and accelerate the development of inclusive international standards for eDNA-based biodiversity monitoring. The task force, which maintains a public presence at iestf.global, represents the first coordinated global effort to bring order to a methodological landscape that has, until now, grown largely organically and without unified oversight.

The core mission of the iESTF is threefold. First, the group intends to identify opportunities for new work item proposals within the framework of the International Organization for Standardization, or ISO — the world’s largest developer of voluntary international standards, whose protocols govern everything from manufacturing quality to environmental management. By channeling eDNA methods through the ISO process, the task force hopes to produce standards that carry genuine international weight and can be adopted by national standards bodies, regulatory agencies, and commercial laboratories worldwide. Second, the iESTF plans to catalog existing standards and best practices that have already emerged at national and regional scales, creating a comprehensive map of what has been done and where gaps remain. Third, and perhaps most ambitiously, the task force is committed to ensuring that the standards development process is accessible to practitioners in nations historically underrepresented in eDNA research — a recognition that biodiversity monitoring is most urgently needed in regions where scientific infrastructure and funding have been scarcest.

The urgency of this effort becomes clear when one considers what has already happened in the absence of international coordination. Standards development efforts have begun to emerge at national and regional levels — for example, individual countries and regional bodies have started drafting their own guidelines for eDNA sample collection, laboratory analysis, and data reporting. While these efforts are valuable in themselves, the authors of the new paper warn that the lack of international coordination risks producing fragmented or even contradictory guidelines. If one jurisdiction requires a particular filtration volume and another mandates a different one, or if two regions prescribe incompatible bioinformatic workflows, the resulting standards could hinder rather than advance the field. Data collected under one regime might be unusable in another, undermining the very comparability that makes eDNA so powerful for tracking biodiversity change across borders and over time.

Standardization, the authors argue, is widely recognized as an essential prerequisite for building confidence among end users — the regulators, resource managers, consultants, and industry stakeholders who ultimately decide whether eDNA methods become routine tools or remain confined to research publications. Without agreed-upon protocols, a result from one laboratory cannot be independently verified by another with confidence. Without common reporting standards, meta-analyses that pool data from multiple studies become statistically fraught. Without validated performance criteria, it is impossible to state definitively what an eDNA survey can and cannot detect, or under what conditions. These are not abstract concerns; they are the practical questions that determine whether an environmental agency can rely on eDNA to declare a species absent from a waterway, or whether a mining company’s environmental impact assessment will stand up to legal scrutiny.

The iESTF’s vision extends beyond simply writing documents. The task force outlines plans for the formation of a truly inclusive international community of practice — a network of researchers, practitioners, and standards professionals who can contribute expertise from diverse geographic, disciplinary, and institutional perspectives. It also proposes the establishment of pipelines for fast-tracking the development of international standards, a recognition that the traditional standards development process, which can take many years, may be too slow to keep pace with a rapidly evolving field. In addition, the task force intends to support critical activities such as cross-regional standards testing and validation, in which the same protocols are applied to identical samples in laboratories across different countries and continents to verify that results are reproducible and comparable. Such interlaboratory exercises are a cornerstone of analytical chemistry and microbiology, and their systematic application to eDNA would represent a major step toward methodological maturity.

The technical challenges that the iESTF must navigate are substantial. eDNA analysis involves a multi-stage workflow — from field sampling design and water or soil collection, through filtration and preservation, to laboratory DNA extraction, amplification or shotgun sequencing, and finally bioinformatic processing and taxonomic assignment. Each stage introduces potential variability, and each has spawned competing approaches in the literature. Contamination control, for instance, is a perennial concern given the extremely low concentrations of target DNA in environmental samples. Reference databases linking DNA sequences to species names remain incomplete for many taxonomic groups and geographic regions, complicating the interpretation of results. Quantitative interpretation — moving from detecting a species’ DNA to estimating its abundance or biomass — remains an active area of research with no settled consensus. Any international standard must grapple with these scientific uncertainties while remaining practical enough to be implemented in laboratories with varying levels of equipment and expertise.

The inclusive dimension of the iESTF’s mandate deserves particular attention. Historically, the development of international scientific standards has been dominated by institutions in wealthy nations, and the same pattern holds in eDNA research, where the majority of publications and funded projects originate from North America, Europe, East Asia, and Australia. Yet the planet’s richest biodiversity is concentrated in tropical and developing regions that are often least represented in the technical conversations that shape how biodiversity will be measured. By explicitly committing to accessibility for practitioners in historically underrepresented nations, the task force is acknowledging that standards developed without broad participation risk being ill-suited to the conditions, capacities, and ecological priorities of the places where they are most needed. Capacity building, technology transfer, and equitable authorship are therefore woven into the initiative’s stated goals rather than treated as afterthoughts.

If the iESTF succeeds, the implications for biodiversity science and environmental policy could be profound. Standardized, internationally recognized eDNA methods would allow monitoring data collected in one country to be directly compared with data from another, enabling truly global assessments of species distributions, invasion dynamics, and ecosystem change. Regulatory agencies would gain a defensible basis for incorporating eDNA into compliance monitoring, environmental impact assessment, and protected-area management. Commercial laboratories would benefit from clear performance benchmarks, and researchers would be freed from the burden of justifying methodological choices anew in every study. The authors of the new paper position the task force as a critical step toward ensuring that eDNA methods achieve their full potential as reliable, globally comparable tools for biodiversity monitoring — a goal that, in an era of accelerating species loss and rapid environmental change, has never been more urgent. Whether the initiative can deliver on that promise will depend on sustained participation from the international community, but its launch marks the moment when eDNA standardization moved from aspiration to organized global action.

Subject of Research: International standardization of environmental DNA methods for biodiversity monitoring

Article Title: The International eDNA Standardization Task Force (iESTF): toward development of inclusive international standards for eDNA biodiversity monitoring

Article References: Hajibabaei, M., Leese, F., Abbott, C., Araki, H., Baird, D. J., Beja, P., Deiner, K., Doi, H., Fahner, N., Goodwin, K. D., Hunter, M. E., Kelly, R. P., Klymus, K., Kondoh, M., Mapholi, N. O., Minamoto, T., Pochon, X., Porter, T. M., Theroux, S., … Meissner, K. (2026). The International eDNA Standardization Task Force (iESTF): toward development of inclusive international standards for eDNA biodiversity monitoring. Metabarcoding and Metagenomics, 10, Article e193334. https://doi.org/10.3897/mbmg.10.193334

Image Credits: AI Generated

DOI: 10.3897/mbmg.10.193334

Keywords: environmental DNA, eDNA, biodiversity monitoring, standardization, ISO, metabarcoding, ecological monitoring, DNA sequencing, conservation, international standards, task force, environmental assessment

Mediterranean-type ecosystems, often abbreviated as MTEs, occur in just five places worldwide: the Mediterranean Basin, California, central Chile, southwestern Australia and South Africa. Despite their separation by vast oceans, these regions share a distinctive climate signature of hot, dry summers and cooler, wetter winters, a regime that has shaped extraordinary concentrations of endemic plant species found nowhere else. The Intergovernmental Panel on Climate Change has reported extreme droughts across all five regions in recent decades, with particularly severe events documented in South Africa and California. These are, in other words, ecosystems under sustained and intensifying climatic pressure, and understanding how their vegetation is actually responding is a matter of global conservation urgency.

The review’s methodology was deliberately rigorous. The researchers systematically searched the literature for observational studies, as opposed to modeling exercises or controlled experiments, that reported climate change impacts on plant communities in these five regions. The screening process yielded 128 publications, a figure that in itself reveals how thin the observational record is relative to the ecological importance of these systems. Each study was then catalogued by region, by the type of disturbance reported, by the aspect of vegetation examined, and by the strength of the evidence linking observed changes to climate change. The resulting map of research effort, illustrated by the review’s global synthesis of 154 reported disturbance observations across the 128 publications, exposes a field that is productive in some places and nearly silent in others.

That silence is concentrated in the Global South. With only 9 percent of the reviewed studies conducted there, central Chile, southwestern Australia and especially the Cape Floristic Region of South Africa are dramatically underrepresented relative to California and the Mediterranean Basin. The authors argue that this imbalance is not a trivial matter of bibliographic accounting. As Jasper Slingsby explains, it limits how confidently scientists can generalise from one Mediterranean-type ecosystem to another. A response documented extensively in California or the Mediterranean Basin may not necessarily predict how vegetation will respond in the Cape Floristic Region, where evolutionary history, fire regimes, soil types and species compositions differ profoundly. The geographic skew means researchers currently cannot distinguish genuine ecological differences between regions from differences that simply reflect where researchers happen to have worked.

The review also mapped which disturbances are most frequently reported. Climate variability, drought, wildfire, frost, and pathogens or insect infestations topped the list, a pattern that tracks the pressures these ecosystems are expected to face as warming proceeds. Yet the aspects of vegetation being measured were far narrower. Most studies examined vegetation condition and growth, while far fewer investigated plant diversity, phenology, the timing of biological events such as flowering and leaf-out, or plant physiology. Some categories of response were not represented at all in particular regions, leaving entire dimensions of ecosystem change unmonitored in places where change is likely to be rapid. For a set of ecosystems whose defining feature is their exceptional plant endemism, the scarcity of diversity-focused observational studies is a particularly consequential blind spot.

Perhaps the most technically significant finding concerns causal inference. Although the review found relatively high confidence in evidence linking climate change-related disturbances to vegetation responses, confidence dropped markedly when studies attempted to demonstrate that climate change itself had caused the observed biological changes. As Ryan Blanchard explains, seeing that vegetation has changed at the same time as climate has changed does not necessarily tell us that climate change caused that vegetation change. Many other factors can be involved, including fire, land use change, herbivory, invasive species and natural ecological variability. In fire-prone Mediterranean-type ecosystems especially, where burning is a natural and often essential ecological process, disentangling climatic signals from disturbance legacies is a formidable analytical challenge that most observational studies have not attempted.

Few of the observational studies included in the review employed modern causal inference approaches, the statistical frameworks that allow researchers to move beyond correlation and test whether a hypothesised driver actually produced an observed effect. This methodological gap, the authors argue, is also an opportunity. Vast amounts of ecological data already exist in long-term monitoring records, historical vegetation surveys and herbarium collections, and reanalysis of these datasets with contemporary causal methods could extract far more reliable evidence than has been achieved so far. Rather than waiting decades for new observations to accumulate, the field could make better use of what it already has, provided that existing data are curated, harmonised and revisited with the analytical tools now available.

The path forward, according to the authors, is coordination. They advocate research programmes deliberately designed across all five Mediterranean-type ecosystems, integrating long-term monitoring, existing observational datasets, remote sensing, controlled experiments and causal inference methods into a single comparative framework. As Hana Petersen puts it, this is not simply a matter of filling gaps on a map. What is needed is an understanding of whether the mechanisms driving resilience in one region can help anticipate what will happen in another. Comparative networks of this kind have transformed other areas of ecology, and the five MTEs, with their shared climate regime but independent evolutionary histories, are natural experiments in how similar pressures play out on different biological templates.

The stakes of this evidence gap extend well beyond academia. Mediterranean-type ecosystems support globally important biodiversity and provide water, carbon storage, pollination and other services to densely populated regions on five continents. The review found that only 11 of the 128 studies were represented in IPCC assessment reports, meaning that the international scientific consensus process is drawing on a remarkably thin observational foundation when it characterises how these ecosystems are faring. A coordinated, causally rigorous and geographically balanced research effort could strengthen understanding of climate-driven vegetation change and directly support conservation planning and climate adaptation in some of the world’s most important biodiversity hotspots, before the window for effective intervention narrows further.

The study, published in Ecological Solutions and Evidence on 4 August 2026, arrives at a moment when the scientific community is increasingly scrutinising not just what is known about climate change impacts, but how and where that knowledge is produced. Its message is sobering but constructive: the observational evidence base for some of the world’s most climate-vulnerable ecosystems is uneven, under-represented in the Global South and methodologically limited, yet the tools and data needed to remedy these shortcomings largely already exist. Whether the next decade of research rises to that challenge will shape how well humanity can anticipate, and perhaps cushion, the ecological transformations now underway in the Mediterranean Basin, California, central Chile, southwestern Australia and South Africa alike.

Subject of Research: Observed climate change impacts on plant communities in Mediterranean-type ecosystems

Article Title: Global review reveals major blind spots in our understanding of climate change impacts on Mediterranean ecosystems

Article References: Global review reveals major blind spots in our understanding of climate change impacts on Mediterranean ecosystems. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: Mediterranean-type ecosystems, climate change, plant communities, systematic review, biodiversity hotspots, drought, wildfire, causal inference, Global South, conservation, IPCC, ecological monitoring

The significance of the work lies in what foraminifera can reveal. Because the standing crop, diversity and species composition of benthic foraminiferal communities respond rapidly to shifts in salinity, pH, dissolved oxygen, organic matter input and anthropogenic stress, they serve as powerful bioproxies for ecological monitoring. Indices such as the FORAM Index, originally developed for coral reefs and later extended to estuaries, and Foram-AMBI, which assigns observed taxa to sensitivity eco-groups, depend entirely on accurate species-level taxonomy and region-specific reference data. Without a reliable local inventory, misidentification or missing baseline information can compromise the ecological interpretations drawn from these tools. The new study directly addresses that gap for a globally significant but understudied region.

The research focused on two contrasting mangrove systems. The first is the Indian portion of the Sundarbans, which covers 9630 square kilometres, of which 4267 square kilometres is forested, and hosts 24 species of true mangroves. Seven major rivers flow through the delta; the Hooghly and Mooriganga still receive freshwater from the Ganges-Brahmaputra-Meghna system, delivering the world’s second-largest freshwater input of roughly 42,000 cubic metres per second, surging to 138,700 cubic metres per second during the monsoon. The remaining five rivers have lost their freshwater connection to the Ganga and are tidally fed, producing a steady salinity gradient that rises towards the east. The second study area, the Budhabalanga estuary near Chandipur, is a smaller system dominated by Avicennia officinalis, Ceriops decandra, Rhizophora mucronata and Phoenix paludosa, and home to the mangrove horseshoe crab Carcinoscorpius rotundicauda.

Both systems face mounting pressure. Previous research has estimated that air temperature over the Sundarbans is increasing at 0.19 degrees Celsius per year, while relative sea level rises at close to 3.14 millimetres per year. The IPCC Sixth Assessment Report projects a further 0.5 degree Celsius increase in mean temperature and a 10 to 45 centimetre rise in sea level across the Sundarbans. A coastal vulnerability assessment of a 269 kilometre stretch of coastline found that approximately 42 percent falls within moderate to very high vulnerability categories. Against this backdrop, establishing which foraminiferal species persist, where they occur, and how assemblages differ between ecosystems provides an essential reference point for detecting future shifts.

Methodologically, the team compiled published studies that reported benthic foraminiferal assemblages from mangrove-associated environments with sufficient species-level taxonomic detail, excluding work that lacked such information or focused on non-mangrove settings. They then collected 112 sediment core samples across the region: 30 from Ajmalmari, Dulibasani and Chulkathi in the Sundarbans Biosphere Reserve between June 2019 and November 2020, four from Dhanchi in January 2024, 72 from Sagar Island between November 2021 and October 2022, and six from the Budhabalanga estuary between 2021 and 2022. Sampling took place at low tide from intertidal mangrove-associated mudflats using a hand-held vertical corer, 10 centimetres long and 3.5 centimetres in diameter, ensuring consistent sampling volume across sites.

In the laboratory, the uppermost 0 to 2 centimetres of each core were homogenised and subsampled, with roughly 10 cubic centimetres of sediment analysed in full. Specimens were stained with Rose Bengal at 1 gram per litre to distinguish living individuals, whose cytoplasm takes up the stain, from dead tests, and preserved in 70 percent molecular-grade ethanol. The sediment was wet-sieved through stacked 500 and 63 micrometre meshes, and the fraction larger than 63 micrometres was examined under an Olympus BX 53i bright-field microscope at 400 times magnification. Taxonomic identifications were verified against the World Register of Marine Species, the Foraminifera.eu database and established taxonomic references, with surface water temperature and salinity measured in triplicate at each site using calibrated instruments equipped with automatic temperature compensation.

The contemporary samples yielded a rich if modest picture. In the Sundarbans Biosphere Reserve, the team recorded 13 taxa, eight calcareous and five agglutinated, belonging to nine families, while Sagar Island yielded 14 taxa, ten calcareous and four agglutinated. Assemblages were dominated by small specimens under 500 micrometres, a feature typical of mangrove environments worldwide. The intertidal communities included the calcareous taxa Ammonia sp.1, Ammonia sp.2, Bolivina sp.1, Elphidium and Nonionella stella, the porcelaneous Quinqueloculina seminulum, and the agglutinated Entzia macrescens, Trochammina inflata and Textularia agglutinans. Notably, the standing crop of live tests was extremely low, below 3 percent in the Sundarbans and below 1 percent at Chandipur, meaning dead shells overwhelmingly dominate the assemblages, a pattern consistent with earlier regional studies and one that makes time-averaged death assemblages an effective basis for documenting regional species inventories.

To assess spatial structure, the researchers built a species-site occurrence matrix in which each taxon was coded as recorded in the literature, in the present study, or in both, then applied Bray-Curtis similarity analysis with UPGMA hierarchical clustering in the R statistical environment. The results were striking: the contemporary Sundarbans sites of Chulkathi, Ajmalmari, Dhulibhasani, Sagar Island and Dhanchi clustered tightly together, indicating broadly comparable assemblages despite differences in location and sampling period. The Chandipur site in the Budhabalanga estuary, by contrast, formed a separate cluster, reflecting differences in community composition even though several dominant taxa are shared. One species, the calcareous Asterorotalia pulchella, was recorded only at Chandipur and was absent from the Sundarbans assemblages, contributing to that separation.

The study’s interpretation of these patterns draws on global comparisons. Mangrove foraminiferal communities worldwide tend to be low-diversity and often dominated by agglutinated forms, as documented in Puerto Rican mangrove-lagoon systems, French Guiana’s Kaw estuary, Australian intertidal flats and Brazilian mangrove estuaries. Tidal elevation strongly influences the balance: agglutinated taxa such as Entzia macrescens and Trochammina inflata favour higher intertidal positions, while calcareous forms like Ammonia are common in mudflat zones. The co-occurrence of both groups in the Bay of Bengal samples is consistent with ecological zonation across mangrove microhabitats. The dominance of Ammonia species, described in the literature as opportunistic generalists with rapid reproduction and broad physiological flexibility, alongside the ecologically tolerant Quinqueloculina seminulum and the widespread agglutinant Entzia macrescens, underscores the resilience of a core regional species pool adapted to salinity fluctuations, organic enrichment and hypoxic conditions.

The authors are careful to acknowledge limitations. The compiled dataset integrates studies spanning different periods, locations and methodologies, which may introduce sampling bias and underrepresent rare, cryptic or seasonally restricted taxa, and shifting taxonomic nomenclature complicates species-level comparisons despite standardisation against contemporary databases. The study was not designed to quantify environmental drivers or seasonal variation, so interpretations remain qualitative. Even so, the strong agreement between historical records and new observations confirms the persistence of key taxa across years and sampling campaigns, and the discovery elsewhere of the endemic agglutinant Srinivasania sundarbanensis hints at undocumented diversity still awaiting description. What emerges is a robust, region-specific framework: a verified checklist of benthic foraminifera for the mangroves of the northeast Bay of Bengal that can anchor foraminifera-based ecological monitoring, sharpen biotic indices, and help conservationists track how these climate-stressed coastal ecosystems respond in the decades ahead.

Subject of Research: Benthic foraminiferal assemblages and their use as ecological indicators in Bay of Bengal mangrove ecosystems

Article Title: Inventorization of spatial patterns and reassessment of benthic foraminiferal assemblages from mangrove ecosystems of Bay of Bengal

Article References: Mandal, A., Ghosh, A., & Bhadury, P. (2026). Inventorization of spatial patterns and reassessment of benthic foraminiferal assemblages from mangrove ecosystems of Bay of Bengal. Discover Oceans, 3(1), Article 63. https://doi.org/10.1007/s44289-026-00169-7

Image Credits: AI Generated

DOI: 10.1007/s44289-026-00169-7

Keywords: benthic foraminifera, mangroves, Sundarbans, Bay of Bengal, Budhabalanga estuary, ecological monitoring, bioproxy, Bray-Curtis clustering, Ammonia, Entzia macrescens, sea-level rise, species inventory