To investigate how the El Niño-Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO) influence zooplankton diversity and community structure in the central Chile coastal upwelling system, focusing on long-term changes in species composition and abundance under shifting climatic conditions.
Eastern South Pacific off central Chile, covering an area of approximately 38,500 km2.
2003–2020.
Zooplankton, with emphasis on dominant groups such as copepods, jellyfish, radiolarians, siphonophores and cladocerans.
We analysed an 18-year time series of zooplankton abundance and composition. Partial Canonical Correspondence Analysis (pCCA) examined relationships between zooplankton groups, the PDO and environmental variables (sea surface temperature, dissolved oxygen, wind). Threshold Indicator Taxa Analysis (TITAN) identified taxa characteristic of warm (PDO+) or cold (PDO–) phases, clarifying their roles as either sensitive or tolerant indicators of climatic shifts.
Warm phases (PDO+) were dominated by jellyfish, siphonophores and pteropods, whereas cold phases (PDO–) favoured radiolarians and cladocerans. Copepods, the most abundant group, exhibited notable fluctuations across climate phases. Zooplankton diversity showed an ‘in-phase’ response to climatic oscillations, indicating strong links between decadal-scale climate regimes and ecosystem dynamics in this productive upwelling region.
Our findings underscore the sensitivity of marine zooplankton communities to climate variability, with distinct PDO phases exerting significant influence on zooplankton composition and diversity. Recognising key indicator taxa in warm versus cold periods is crucial for ecosystem management and developing indicator-based monitoring programs. Continued long-term surveys will be essential to anticipate future shifts in marine biodiversity under ongoing climate change.
Endemism is a critical aspect of biological diversity, yet the mechanisms driving it remain unclear. The leading hypothesis posits that prolonged environmental stability fosters speciation and reduces extinction rates, promoting endemism. While terrestrial studies exist, marine environments remain underexplored. This study analysed the global distribution and drivers of phylogenetic endemism in two marine taxa: Calanidae copepods and Blenniidae fish.
Global.
From the Last Glacial Maximum (LGM, past 24,000 years) to the current period.
Calanidae copepods and Blenniidae fish.
We assessed taxonomic and phylogenetic diversity, endemism and areas of paleo- and neo-endemism using Categorical Analysis of Neo- and Paleo-Endemism and Piecewise Structural Equation Modelling to evaluate the influence of present-day and historical environmental variables.
Results showed consistent diversity patterns and significant endemism hotspots, with Calanidae in the Southern Hemisphere and Blenniidae in the Northern Hemisphere. Tropical regions, particularly the Indonesian-Australian Archipelago (IAA), exhibited high species richness and endemism for both groups. Paleo-endemism was observed in the Pacific for Calanidae and the IAA for Blenniidae, suggesting that these areas are either relict diversity centres or diversification hubs.
The Mediterranean and Caribbean Seas emerged as biodiversity cradles for Calanidae and Blenniidae respectively. Phylogenetic endemism is driven by both historical and contemporary factors, with centres of endemism emerging in regions where past environmental fluctuations have been moderate (hypothesis 1) and where cold, productive ocean currents foster the development of endemic areas (hypothesis 2). These findings underscore the importance of historical stability in ocean temperatures in shaping phylogenetic endemism, indicating that long-term environmental stability sustains marine endemism.
To test how evolutionary processes of spiders in mountain ranges of eastern China were in response to environmental changes, we analyze the correlation between diversification of the Pardosa laura species complex (Araneae, Lycosidae) and historical climates and mountains in this region.
We reconstruct phylogenetic relationships and patterns of phylogeography and genetic diversity using mtDNA data from samples spanning the full range of the species complex P. laura in eastern China.
The P. laura species complex clustered into four lineages: Lineage I includes five haplotypes from the areas to the north of the Yinshan-Yanshan Mountains; Lineage II consists of 23 haplotypes from the areas between the Qinling Mountains–Huaihe River Line and the Nanling Mountains; Lineage III and IV are composed of 21 and 62 haplotypes, respectively, from the areas between the Yinshan-Yanshan Mountains and the Nanling Mountains. Each lineage corresponds to that, grouped from haplotype network analyses, with the same geographic distribution areas. All four lineages initially diversified during about 1.43 and 0.24 Ma ago (Ma) in relation to the Pleistocene glacial-inglacial cycles. The biogeographic reconstructions suggest that the species complex P. laura most likely originated in central China around 7.68 (11.17–4.85) Ma in relation to the recent (approximately 8 Ma) expansion of grasslands and retraction of forests. The inter-colony dispersal between central China and northeastern China occurred during the late Neogene, between around 7.68 and 3.14 Ma. Central China is an important dispersal center, with dispersal to southwestern and northern China between the late Pliocene and middle Pleistocene, approximately 3.14–2.89 and 2.89–1.43 Ma, respectively.
The contemporary genetic structure of the P. laura species complex presents a high correlation between lineages and geographic distribution. The historical phylogeographic patterns suggested that the late Cenozoic climate changes and the mountainous corridors and isolation events, as well as the lineage dispersals and ecological adaptations shaped the diversification of a spider species complex in eastern China over long timescales.
This study had four aims: (1) to group traditional mesophilous indicator species of Illyrian forests based on their distribution patterns; (2) to gain insight into the biogeographic attributes of each group by hotspot analyses; (3) to clarify the level of importance that certain species have in the floristic differentiation of Illyrian from non-Illyrian forests; (4) to explore the possible distribution of Illyrian mesophilous forests.
Europe, Asia and Africa.
Illyrian forest understory plant species.
A dataset of 40 understory plant species traditionally associated with Illyrian forests was compiled from the literature. The distribution of these species was digitised in the form of polygons, following numerous sources. A 25 × 25 km grid cell system was established to convert the polygon distribution data into a matrix. This matrix was used for hierarchical clustering in order to classify species based on distribution into groups. Hotspot analysis was performed for groups using Getis-Ord Gi* analysis. The dataset was further divided into clusters to reveal less pronounced distribution patterns.
The classification resulted in three major groups of species: (1) a Steno-Illyrian group, with a restricted hotspot area mostly distributed in Slovenia and Croatia; (2) a Sub-Illyrian group, with a larger distribution area but with a significant part of the distribution located in the Dinarides; and (3) a Pseudo-Illyrian group, which has a widespread distribution across Europe, North Africa and parts of Asia. Hotspot analysis identified the Dinarides as the main area of Illyrian understory plant diversity, with extensions into the Southern Alps and some Pannonian mountains and hills.
The area of the Dinarides and Southern Alps is characterised by the presence of Steno-Illyrian species and a high-frequency overlap with Sub-Illyrian species. Pseudo-Illyrian species lack biogeographic specificity and therefore cannot be used to identify Illyrian forests.
Studies on the geographical distributions of marine species have typically ignored the oceans' inherent 3D nature, instead focusing on two-dimensional patterns based on surface or near-surface abiotic conditions. Here, we show the importance of considering oceans as 3D space by comparing fish species richness patterns inferred from 2D and 3D data sources, including species occurrences and environmental data.
Atlantic Ocean.
Present.
Three orders of bony fishes—Beloniformes, Gadiformes and Scombriformes.
We generated 2D and 3D species distribution models using two methods: general linear models and simple envelopes. We then summed distributions for each order to map potential species richness in the Atlantic Ocean. Finally, we modelled species richness within each order to examine macroecological patterns based on 2D versus 3D data.
Our 3D species richness maps provide a different picture of potential distributions of diversity than 2D-based results, especially for Scombriformes and Gadiformes, which generally inhabit sub-surface waters. In contrast, 2D and 3D results for Beloniformes, which are generally epipelagic, were quite similar. Using linear models of species richness, we demonstrate disparity among macroecological patterns inferred based on 2D versus 3D data.
Overall, our work emphasises the critical importance of depth in the study of marine ecosystems and the need for detailed depth information associated with organism occurrence records and oceanographic data.
We aimed to understand the ecological connections between caves and mesovoid shallow substratum (MSS) in Iron Formations from southeastern Brazil.
Iron Quadrangle and Southern Espinhaço Range, southeastern Brazil.
Subterranean invertebrates.
Our dataset compiles species distribution data of subterranean invertebrates from long-term monitoring projects conducted in three localities: Brumadinho, Itabirito, and Conceição do Mato Dentro. Sampling occurred from April 2007 to December 2023 using active search methods in caves and MSS traps in iron-duricrust (canga) formations. We used multivariate analyses to compare the invertebrate composition between caves and MSS. We also assessed the effect of geographic distance between them on total β-diversity, species replacement, and richness differences.
We recorded 97,967 individuals and 1588 invertebrate morphospecies: 11,738 individuals and 994 morphospecies in caves, and 86,229 individuals and 945 morphospecies in MSS. Six phyla were sampled, with Arthropoda comprising 98% of all organisms. In total, 351 invertebrate morphospecies (22.1%) were shared between caves and MSS, with 643 (40.5%) sampled only in caves and 594 (37.4%) restricted to MSS. Only four subterranean-specialised invertebrates were shared between caves and MSS. Species composition differed more between subterranean environments than between localities, with β-diversity analyses revealing high species replacement as the primary driver. Geographic distance played a negligible role in compositional differences (Sorensen dissimilarity) between caves and MSS, with β-diversity always above 83% regardless of the distance between these environments.
Caves and MSS in Iron Formations support distinct subterranean invertebrate communities, with more species restricted to each environment than shared, regardless of the geographic distance or structural connectivity between them. These findings highlight the ecological relevance of both environments and their role in sustaining biodiversity within Iron Formation systems. Consequently, conserving both environments is needed to protect the full extent of subterranean biodiversity in these unique ecosystems.
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