Climate change and vertical thermal stratification of the water column in the Mediterranean Sea: implications for marine aquaculture.

Climate influences species performance and distribution both directly, through physiological constraints, and indirectly, by modulating biotic interactions. However, the relative importance of these pathways remains poorly understood, limiting our ability to predict species responses to environmental change. Here, we investigated how microclimate influences the growth of a cold-adapted lichen both directly and indirectly, through effects on mollusc grazing, and whether these effects differ among populations of different origins. We conducted a transplant experiment using lobes of Peltigera aphthosa collected from five geographically distant populations along a 1200-km latitudinal gradient in Sweden. The lobes were transplanted to 56 forest sites spanning a broad microclimatic gradient near the species' warm-range margin in Sweden, and we monitored their growth and grazing damage for one year. Using piecewise structural equation models, we quantified the direct and indirect effects of microclimate through grazing on lichen growth and assessed whether these effects differed among source populations. We found no evidence for direct effects of microclimate on lichen growth. Instead, microclimate indirectly influenced growth through mollusc grazing. Grazing damage increased with warmer temperatures (more growing degree days) and higher air humidity (lower vapour pressure deficit) during the growing season and grazing reduced lichen growth. While population origin did not affect direct responses to microclimate, populations differed in their susceptibility to grazing. Our study highlights the importance of indirect microclimatic effects mediated by biotic interactions in shaping species performance near its warm-range margin. The absence of direct microclimatic effects, combined with intraspecific variation in susceptibility to grazing, underscores the need to consider both biotic interactions and differences among populations when predicting species responses to climate change. Transplant experiments across microclimatic gradients offer a valuable method to gain insights into the complex interplay between local adaptation and abiotic and biotic factors of species performance.

Ponds are biodiversity hotspots that harbor diverse macro-organisms and microbial communities, despite being isolated, highly variable environments with island-like features. These factors may give rise to unique biogeographic patterns and drivers of microbial community diversity. Here, we evaluated environmental and regional drivers of pond fungal and bacterial biodiversity to determine whether these communities follow commonly observed biogeographical trends. We collected water and muck from 40 ponds across 8 states in the Eastern USA and sequenced sections of the 16S rRNA and ITS1 genes to survey the bacterial and fungal communities and test (1) whether these communities follow latitudinal diversity gradients and distance decay relationships, and (2) if variation in community composition or richness was related to specific environmental or land-use factors. We found that pond microbial communities exhibit distinct distribution patterns and relationships with environmental drivers depending on the microhabitat and microbial taxa. For example, muck fungal communities followed latitudinal diversity gradients, but bacterial communities did not. Abiotic conditions explained more variation than surrounding land use or the distance between sites, with temperature universally linked to microbial biodiversity. However, all sample types displayed weak distance-decay relationships, likely because of low spatial autocorrelation in environmental conditions and the lack of connectivity across ponds.

The responses of anurans to paleogeology, climate variability and anthropogenic factors play a crucial role in understanding their diversity and population dynamics. Despite substantial phylogeographic studies existing for northeast Asia, a region-wide synthesis linking divergence timing with major evolutionary drivers is lacking. To address this gap, we synthesised published divergence-time estimates for northeast Asian anurans from 1998 to present, and linked basal, stem and crown ages to their associated drivers and regional contexts. We integrated the data with time-calibrated genomic species trees, diversification analyses, and three key trait data (body size, elevation and latitude range) to assess temporal patterns of lineage divergence and compare diversification dynamics among the major anuran families in northeast Asia. Our synthesis identifies four recurrent evolutionary drivers: (1) paleogeology and landscape barriers, (2) climate fluctuations and latitudinal gradients, (3) glaciations and past sea-level change, and (4) anthropogenic influences. Across families, we highlight unresolved species boundaries, detect the genetic imprint of human-mediated disturbance, synthesise phenotypic, ecological, and macroevolutionary patterns using openly available datasets, and identify cases where multiple drivers interact within species complexes. Bayesian Analysis of Macroevolutionary Mixtures (BAMM) trait reconstructions showed that across all three traits, Ranidae had the highest trait values through time, indicating broader ecological breadth and greater macroevolutionary expansion than Bufonidae and Microhylidae. Our synthesis integrates divergence timing, trait evolution, and environmental drivers, providing a general framework for understanding biodiversity responses to long-term environmental change.

ABSTRACTThe habitat suitability of the endangered Asian elephant (Elephas maximus) is commonly assessed using climatic and topographic variables, whereas food‐plant resources are rarely incorporated explicitly into regional‐scale species distribution models. Here, we developed a comparative modeling framework to evaluate how the inclusion of food‐plant resource layers modifies Asian elephant habitat suitability predictions under current and future climate scenarios. (1) The model incorporating food‐plant variables produced a more restricted and spatially concentrated pattern of suitable habitat than the model excluding food‐plant variables. (2) This contrast suggests that climate‐dominated models may overestimate usable habitat in areas where key forage resources are limited or absent. (3) In addition, piecewise SEM suggested that the associations among climate, topography, food‐plant resources, and predicted habitat suitability varied along latitudinal gradients. These findings indicate that food‐plant resource layers can refine climate‐based habitat suitability assessments by distinguishing broad climatic suitability from more realistic resource‐based suitability. Conservation planning should therefore integrate food‐plant restoration, habitat connectivity, and climate adaptation to improve habitat management and reduce human‐elephant conflict.

Zooplankton spatial patterns along the Ob River continuum: Integrating hydrology, chemistry, and landscape controls.

Abstract Microbial diversity is a key driver of ecosystem function, yet it remains poorly integrated into ecological restoration frameworks. While seeds are the primary dispersal unit of plants and the foundation of most restoration programs, the microbial communities they carry are rarely considered. Here, we assess whether sites that have undergone restoration have altered seed-associated microbial communities. We do this by comparing bacterial and fungal seed microbiomes across natural and restored landscapes. Using a landscape-scale sampling design, seeds were collected from multiple plant host species and populations across 41 sites spanning a broad latitudinal gradient. High-throughput sequencing of the 16S rRNA gene and ITS2 region was used to characterise bacterial and fungal communities, respectively, and differences in diversity, composition, and network structure were assessed using multivariate and network-based approaches. Seed microbiomes differed between natural and restored sites, but the magnitude and nature of these changes varied among host species. Restored sites were associated with shifts in microbial diversity, community composition, and network structure, including changes in the retention of putative keystone taxa. In some species, restoration was linked to pronounced restructuring of seed-associated microbial communities, whereas in others, microbiomes remained comparatively stable. Together, these results demonstrate that restoration can alter seed microbial communities in ways that are not consistently predicted by soil-focused restoration outcomes and that host identity mediates these responses. Incorporating seed microbiome data into restoration monitoring may therefore provide a complementary and previously overlooked indicator of restoration success, with implications for improving plant germination and health.

Phenotypic plasticity and local adaptation jointly shape plant responses to environmental variation, but their relative contributions and trait-specific interactions remain poorly understood. (1) We quantified metabolites and measured growth, reproduction and herbivore resistance-related traits in 15 Fragaria vesca genotypes from a European latitudinal gradient grown reciprocally in four common gardens over two years. (2) Environment explained most trait variance (30%), followed by genotype × environment interactions (18%) indicating evolved plasticity, then genotype (9%). (3) Northern genotypes exhibited greater plasticity in stress-related metabolites but more canalization in growth-related traits, while southern genotypes maintained constitutively high levels of protective metabolites; this resulted in latitude shaping more than 4% of plasticity profiles. (4) Long-term temperature at origin outperformed precipitation in predicting trait variation across all categories. Synthesis. Plasticity dominates over local adaptation along climate gradients but evolves in a trait-specific manner as a heritable target of selection, buffering populations against climate shifts while also shaping the pace of genetic tracking, critical for predicting range dynamics under climate change.

ABSTRACTThe phenology of bird vocalizations is increasingly employed to understand avian reproduction and territoriality, among other ecological aspects. Although precipitation is ostensibly the major driver of seasonality at the equator, subtle photoperiodic signals are discernible in daylength, with a typical variation of 20 to 25 min over the entire year. However, in hyper‐diverse areas, such as the tropics, environmental cues for phenological patterns are relatively small compared to temperate regions, requiring long‐term data to identify patterns of vocal seasonality. One such source of data comes from the increasing numbers of bird visual and aural records generated by citizen science initiatives, easily accessible through online platforms such as eBird. First, we validated the use of eBird citizen science data for vocal phenology research, demonstrating strong concordance with independent audio recordings. Then, we assessed the vocal phenology of forest tinamous using a large eBird dataset. This work tested the hypotheses that the vocal phenology of tropical forest tinamous is influenced by changes in daylength and precipitation. To test the effect of changes in daylength and precipitation, we grouped records of forest tinamous in five regions with similar precipitation regimes over four latitudinal bands. After filtering, we obtained a total of 44,071 records of 16 forest tinamou species between January 2000 and December 2022. We found that vocal phenology in tropical forest tinamous can be predicted by changes in precipitation but is primarily influenced by changes in daylength. There appears to be a clear difference in singing patterns between the broad regions defined by precipitation regimes. In wetter regions, the effect of precipitation was stronger. Forest tinamous vocalize mainly when precipitation is low, especially in humid regions with similar climatic regimes. They also tend to sing more when days become either longer or shorter, with the lowest vocal activity at 12 h of daylength. Questions such as these, concerning tropical phenology, have been elucidated through the contribution of citizen science to this burgeoning field.

Variations in the latitudinal diversity gradients of the ocean microbiome.

Disentangling mechanisms shaping species richness is fundamental to understanding how biodiversity is structured across geography. The latitudinal diversity gradient (LDG) is a classic pattern in which the tropics harbour the greatest number of species. Patterns deviating from the classic LDG, such as an inverse gradient in which diversity is higher towards the poles, have been considered exceptions and attributed to taxon-specific causes rather than to general processes. Here, we evaluated the simultaneous contributions of various evolutionary and ecological factors to the geographical diversity patterns of New World sparrows (Aves: Passerellidae) at the family and lower clade levels. Three hypotheses were tested: geographical variation in diversification rates, time for species accumulation, and ecological limits. We also explored the influence of dispersal and colonization. A strong inverse diversity gradient was identified for the entire family and five of eight subclades, all of which were best explained by the time for species accumulation hypothesis. Conversely, diversification rates best explain clades exhibiting a classic LDG pattern. Our findings support an 'into the tropics' pattern of colonization, characterized by the origin of Passerellidae in temperate zones, the persistence in these regions and limited dispersal events leading to high diversification rates in the tropics.

From macro to meso: Latitudinal distribution of plastic fragments from the Arctic to the tropics and influence of the environmental conditions.

Contrasting population structures of reef-building corals and their algal symbionts inform adaptive potential across the western Pacific.

ABSTRACTHybridization is widespread across diverse groups of organisms, and in some cases, organellar genomes of one species become fixed in another following hybridization and backcrossing, a phenomenon known as organelle capture. Because cytoplasmic genomes can contribute to local adaptation, organelle capture has the potential to confer a selective advantage and may be maintained by natural selection. Here, we evaluate this hypothesis in Nothofagus trees by analyzing chloroplast and mitochondrial genomes. Organellar phylogenies consistently separate individuals by geography rather than by species, with the two main clades mostly divided into northern and southern groups with a boundary at about 42° S, a pattern not captured by traditional nuclear markers. This major split is estimated to have originated during Pleistocene glaciations, when contraction into refugia and postglacial expansion may have been facilitated by hybridization. Chloroplast genes show signatures of positive selection in protein‐coding genes, with most signals concentrated in the northern clade. These results are consistent with potential adaptation to latitudinal and environmental gradients. In contrast, mitochondrial genes remain conserved under purifying selection, suggesting that mitochondrial patterns may be consistent with co‐introgression alongside chloroplasts. This pattern is consistent with the predominant maternal inheritance of both organelles in angiosperms, unlike gymnosperms where mitochondria are usually maternally and chloroplasts paternally inherited, a difference that may shape organelle capture dynamics. Overall, our results are consistent with a potential pattern of organelle co‐introgression involving the simultaneous introgression of chloroplast and mitochondrial genomes through hybridization. These findings provide a framework for exploring the evolutionary significance of organelle introgression and its potential role in local adaptation and speciation in trees.

The Prunus mume species has undergone a long process of domestication and introduction in China, resulting in marked differences in freezing tolerance among populations across a latitudinal gradient of approximately 1,000 km. However, the introduction and domestication process is time-consuming, constraining the efficiency of species introduction. In this study, P. mume samples with the same genetic background spanning over 1,000 km from north to south were selected as experimental materials. The molecular mechanisms underlying cold-acclimation-mediated freeze tolerance in P. mume were investigated using multiomics high-throughput sequencing and molecular biology techniques. The cold-acclimated plant material exhibited enhanced freezing tolerance. Cold acclimation substantially enhanced transcriptional reprogramming under cold stress, accompanied by the remodeling of chromatin states in the promoter region. A variety of cis-regulatory elements were identified in the open chromatin regions of cold-acclimated plant materials, including G-box, ABRE, and other stress-responsive elements. The bZIP transcription factor PmGBF1, as a key regulatory node, directly regulates the expression of the cold shock protein gene PmCSL by binding to G-box elements to regulate freezing tolerance. This study reveals the molecular mechanism underlying cold acclimation mediated by the PmGBF1-PmCSL pathway in regulating P. mume freezing tolerance, providing an epigenetic theoretical basis and genetic resources for cold-acclimation breeding of freezing tolerance in woody plants.

Latitudinal patterns of food source assimilation and food-chain length in estuarine food webs.

The early Paleocene was a time of dramatic ecological transformation following the Cretaceous–Paleogene (K–Pg) mass extinction. Although terrestrial recovery has been well-studied in the Western Interior of the United States, macrofloral records from early Paleocene Canada remain sparse. Here, we describe a diverse early Paleocene fossil plant assemblage from the Ardley Coal Zone of the Scollard Formation at the Highvale Coal Mine in Alberta. The flora includes 27 leaf, fruit, and seed taxa and is composed of ferns, conifers, and broadleaf angiosperms preserved in floodplain and swamp deposits lying about 14 m above the K–Pg boundary. We present new taxonomic descriptions alongside quantitative palaeoclimate reconstructions using leaf physiognomic and Nearest Living Relative methods. These estimates, synthesized via an ensemble approach, indicate that Highvale supported a warm-temperate (mean annual temperature of 9.6°C), humid forest (relative humidity at 76.8%) with moderate seasonality (driest month precipitation at 4 cm) and moderate net primary productivity (701 gC m−² yr−¹). These results are compared to those from the broadly coeval Genesee and Ravenscrag fossil floras, which reflect a latitudinal climate gradient and localized environmental variation during the early Paleocene in western Canada.

Studies of coevolution, ecosystem processes, and latitudinal diversity gradients are improved by understanding variation in resource specialization. Insect herbivory is one of the most ubiquitous terrestrial ecological associations, and is important for understanding the evolution of both plants and insects, yet the processes underlying global variation in diet breadth remain poorly understood. Here, we use global datasets of butterfly and plant distributions to investigate the patterns and drivers of butterfly larval diet breadth. Diet breadth showed a negative relationship with plant family richness, but this was offset by a direct effect of temperature acting in the opposite direction. Islands generally harbor species with broader diets, but islands with higher endemism had narrower diets than average. Our study provides a global baseline for understanding how plant and herbivore interactions structure ecological communities in the face of global environmental changes.

Global spatiotemporal patterns of heatwaves: a re-evaluation.

Biological and biogenic carbon production in Southwestern Atlantic coralline algal beds.