Diversity

16 pages, 2846 KB

Open AccessArticle

Riparian Tugai Forest Ecosystems of Azerbaijan: Vegetation Structure, Classification and Ecological Characteristics

by Elshad Gurbanov, Tariel Talibov, Vagif Novruzov, Aynur Bayramova, Nigar Ahmadova, Ulkar Bayramova and Sanubar Aslanova

Diversity 2026, 18(7), 441; https://doi.org/10.3390/d18070441 - 21 Jul 2026

Abstract

Tugai forests are intrazonal riparian ecosystems formed along river valleys in arid and semi-arid regions and characterized by high biodiversity and complex vegetation structure. The aim of this study was to assess the phytocenological structure, species composition, and ecological characteristics of tugai forests [...] Read more.

Tugai forests are intrazonal riparian ecosystems formed along river valleys in arid and semi-arid regions and characterized by high biodiversity and complex vegetation structure. The aim of this study was to assess the phytocenological structure, species composition, and ecological characteristics of tugai forests distributed within the Kura River basin and the Nakhchivan Autonomous Republic of Azerbaijan. The study was conducted using classical geobotanical and phytocenological methods based on the Braun—Blanquet approach. The results revealed clear ecological differentiation among tugai forest formations depending on hydrological regime, groundwater conditions, and soil salinity. High species diversity and a multi-layered vegetation structure were identified within the Populeta—Salicetum—Ulmosum, Ulmeta, Populeta, Saliceta—Alnueta—Populeta, and Tamariceta formation groups, which develop mainly on alluvial soils under conditions of elevated moisture. In the Nakhchivan region, tugai forests adapted to more arid environments are distributed mainly along the Araz River and are dominated by Tamarix ramosissima, Populus euphratica, Populus nigra, and Salix species. Anthropogenic impacts, including grazing, deforestation, and hydrological alterations, were identified as major factors contributing to ecosystem degradation and reduction in vegetation cover. The obtained results confirm the high ecological and conservation significance of tugai forests and emphasize the necessity of their protection, restoration, and sustainable management. Full article

(This article belongs to the Section Plant Diversity)

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51 pages, 4065 KB

Open AccessArticle

The Value of Correct Identification of Coastal Marine Fishes of Economic Importance: The Case of the Senegalese Tongue Sole (Pleuronectiformes: Cynoglossidae) in the Eastern Central Atlantic (Africa)

by Paul N’lemvo, Eva Decru, Luis M. da Costa, Soleil Wamuini Lunkayilakio, Jerida Kosi Zola, Jean-Claude Micha and Emmanuel J. W. M. N. Vreven

Diversity 2026, 18(7), 440; https://doi.org/10.3390/d18070440 - 21 Jul 2026

Abstract

The Senegalese tongue sole, Cynoglossus senegalensis, includes three junior synonyms: C. goreensis, C. guineensis and C. simulator. In addition, C. browni, originally described as a subspecies of C. senegalensis, is currently considered a valid species. Recent observations of [...] Read more.

The Senegalese tongue sole, Cynoglossus senegalensis, includes three junior synonyms: C. goreensis, C. guineensis and C. simulator. In addition, C. browni, originally described as a subspecies of C. senegalensis, is currently considered a valid species. Recent observations of C. senegalensis specimens showed two different mouth morphologies, with mouth angle (i) not exceeding the posterior border of the lower eye and with a narrow interorbital distance (IOD) or (ii) exceeding that level and with a wider IOD. The first group represents C. senegalensis. The second, although containing the C. browni holotype, is named C. goreensis, following name priority. A third group, with a mouth angle not exceeding the posterior border of the lower eye and with an intermediately wide IOD, was also revealed. This last group suggests that C. simulator requires revalidation. DNA barcoding results confirmed all three species. This highlights that current Cynoglossus fishery statistics are based on doubtful identifications, probably skewing IUCN assessments. A pictorial guide is proposed to ease identification and help conservation assessments of policies and sustainable management plans for these economically important marine fish species. Common names in English, French and Kikongo (DRC) are proposed to facilitate communication with concerned local communities and to better spread the preservation/conservation message. Full article

(This article belongs to the Special Issue Genetic and Morphological Diversity of Marine Fish Populations)

17 pages, 4941 KB

Open AccessArticle

Palynological Assemblages from the Jurassic Qingtujing Formation in the Northwestern Margin of the Chaoshui Basin: Implications for Geological Chronology and Paleoclimate

by Pengfei Niu, Wenxiu Ren and Guoqiang Dong

Diversity 2026, 18(7), 439; https://doi.org/10.3390/d18070439 - 21 Jul 2026

Abstract

The Qingtujing Formation of the Chaoshui Basin is an important Jurassic coal-bearing unit in the Hexi Corridor. Palynological data on this formation are crucial for regional stratigraphic correlation and paleoclimate reconstruction. In this study, we systematically identified and analyzed the palynological fossils in [...] Read more.

The Qingtujing Formation of the Chaoshui Basin is an important Jurassic coal-bearing unit in the Hexi Corridor. Palynological data on this formation are crucial for regional stratigraphic correlation and paleoclimate reconstruction. In this study, we systematically identified and analyzed the palynological fossils in the Qingtujing Formation in Well Gao 4 and Well 801 on the northwest margin of the Chaoshui Basin and identified two characteristic palynological assemblages. The lower part is the Disacciatrileti–Cycadopites–Osmundacidites assemblage, dominated by gymnosperm pollen, followed by fern spores, with very low Classopollis content. The upper part is the Classopollis–Disaccites assemblage, dominated by gymnosperm pollen, among which Classopollis pollen accounts for a portion as high as 75.5%, and fern spores only appear sporadically. Based on a comparison of palynological assemblages and the distribution pattern of fossils, the sedimentary age of the Qingtujing Formation was determined to be early to late Middle Jurassic. The paleoclimate was reconstructed based on the ecological habits of the pollen/spore-producing plants, indicating that the study area had a warm and humid climate in the early Middle Jurassic and that this climate changed to a hot and dry one in the late Middle Jurassic. This evolution pattern is consistent with the Jurassic climate evolution trend in the northwest of China. These results provide key palynological evidence for the stratigraphic chronology and paleoclimate reconstruction of the Jurassic strata in the Chaoshui Basin. Full article

(This article belongs to the Section Phylogeny and Evolution)

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14 pages, 3346 KB

Open AccessArticle

Genetic Investigations on the Sicilian Populations of Prunus mahaleb L. and Prunus cupaniana Guss ex E. Huet & A. Huet (Rosaceae): Implications for Conservation

by Claudia Mattioni, Salvatore Pasta, Marcello Cherubini, Luca Leonardi, Giuseppe Clementi, Emilio Badalamenti, Giuseppe Traina and Tommaso La Mantia

Diversity 2026, 18(7), 438; https://doi.org/10.3390/d18070438 - 21 Jul 2026

Abstract

Assessing genetic diversity of species and populations can help reduce the risk of biodiversity loss by identifying areas deserving the greatest attention in terms of conservation priority. Our study was focused on evaluating the genetic variability of Prunus mahaleb L. and Prunus cupaniana [...] Read more.

Assessing genetic diversity of species and populations can help reduce the risk of biodiversity loss by identifying areas deserving the greatest attention in terms of conservation priority. Our study was focused on evaluating the genetic variability of Prunus mahaleb L. and Prunus cupaniana Guss. ex E. Huet & A. Huet (Rosaceae), both of which are quite rare and unevenly distributed in Sicily (Italy). In this region, P. mahaleb occurs in scattered populations, mostly concentrated on the mountain ranges close to the northern Tyrrhenian coast, while P. cupaniana, which is endemic in Sicily, is known to occur only on Sicani Mountains and on the Madonie Massif. A total of 118 georeferenced individuals of P. mahaleb and P. cupaniana were sampled across eight different sites. The samples were genotyped using nine unlinked nSSr loci. A high percentage of clonal individuals was observed especially in P. cupaniana. Low intrapopulation diversity, as well as high divergence among populations were recorded. The analysis performed using STRUCTURE separated P. mahaleb and P. cupaniana into two different gene pools (K = 2) and revealed the complete absence of introgression between them. These results, if confirmed through further molecular analysis, indicate that these taxa should be considered as two distinct species. Moreover, more detailed analyses allowed us to distinguish four gene pools for P. mahaleb, while the extant populations of P. cupaniana could be grouped into two clusters suggesting their strong isolation and a very low, if any, absent gene flow between them. Our results underline the urgent need for interventions aimed at conserving and managing the genetic heritage of the Sicilian populations of both species. Full article

(This article belongs to the Section Plant Diversity)

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23 pages, 2225 KB

Open AccessArticle

A Remarkable Diversity of Syngnathid Fishes in a Highly Modified Large Coastal Embayment in the Southeastern Indian Ocean

by Glenn I. Moore, Jenelle A. Ritchie, Georgia M. Nester, Glenn A. Hyndes and Alan J. Kendrick

Diversity 2026, 18(7), 437; https://doi.org/10.3390/d18070437 - 21 Jul 2026

Abstract

Southern Australia supports a high diversity of fishes in the family Syngnathidae, which is recognised as globally threatened, facing threats from coastal development, over-exploitation and bycatch. In southwestern Australia, Cockburn Sound houses a large industrial port and naval defence assets with plans to [...] Read more.

Southern Australia supports a high diversity of fishes in the family Syngnathidae, which is recognised as globally threatened, facing threats from coastal development, over-exploitation and bycatch. In southwestern Australia, Cockburn Sound houses a large industrial port and naval defence assets with plans to substantially expand the port facilities but also sits within a recognised syngnathid ‘hotspot’. Using a broad array of data sources, including historical museum vouchers, published records, historical and contemporary observations from notebooks and diving surveys, historical and contemporary trawl surveys, citizen science observations and environmental DNA, we compiled 4839 records of syngnathid fishes from the embayment. Twenty-one species of seadragons, seahorses or pipefishes were confirmed from an area of around 200 km², representing a high diversity by area on a global scale. This remarkable diversity exists despite the bay being a highly modified system. Many species are likely to face conservation concerns within the bay, but others may benefit from the addition of artificial structures. There is clearly a need to protect the diversity and mitigate detrimental impacts from development and ongoing infrastructure operations, including direct and indirect interaction, habitat loss, water quality, turbidity, noise and introduced pests. Full article

(This article belongs to the Section Marine Diversity)

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13 pages, 17048 KB

Open AccessArticle

The Mediterranean as a Refuge for the Endangered Sand Tiger Shark Odontaspis ferox in a Warming Ocean

by Cemal Turan and Alen Soldo

Diversity 2026, 18(7), 436; https://doi.org/10.3390/d18070436 - 20 Jul 2026

Abstract

The endangered Odontaspis ferox remains a poorly understood large predatory shark, with limited knowledge of its ecological niche and vulnerability to climate change. This study aimed to assess its current and future habitat suitability across the Mediterranean Sea and global oceans using a [...] Read more.

The endangered Odontaspis ferox remains a poorly understood large predatory shark, with limited knowledge of its ecological niche and vulnerability to climate change. This study aimed to assess its current and future habitat suitability across the Mediterranean Sea and global oceans using a species distribution modeling framework. A total of 303 occurrence records were compiled from multiple biodiversity databases and literature sources, and 12 environmental predictors were selected following multicollinearity filtering. Among the tested algorithms, the Random Forest model demonstrated high predictive performance, indicating strong accuracy and reliability. Current projections reveal a highly fragmented distribution, with suitability hotspots concentrated in the eastern and central Mediterranean, particularly in the Aegean Sea, Hellenic Trench, and Ionian Sea, as well as in specific coastal regions globally. Future projections under the SSP2-4.5 scenario (2020–2100) indicate a clear spatial reorganization. Core habitats in the southeastern Mediterranean are projected to persist, while substantial expansion into the northern and central Mediterranean suggests a poleward shift in habitat suitability. In contrast, global projections indicate an overall contraction of suitable habitats. Temperature and primary productivity emerged as the main drivers of distribution patterns. Overall, the results suggest that the Mediterranean Sea may act as a critical climate refuge for O. ferox, highlighting its increasing conservation importance under future ocean warming. Full article

(This article belongs to the Section Marine Diversity)

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36 pages, 18215 KB

Open AccessArticle

Molecular Phylogenetic Reexamination of Trigonostomidae Graff, 1905 (Platyhelminthes, Rhabdocoela), with the Resurrection of Messoplana Den Hartog, 1966, and the Description of Four New Species from the United States

by Yander L. Diez, Marlies Monnens, Tom Artois and L. Holly Sweat

Diversity 2026, 18(7), 435; https://doi.org/10.3390/d18070435 - 20 Jul 2026

Abstract

The rhabdocoel family Trigonostomidae has been the subject of recent phylogenetic revisions. However, due to the limited number of sequenced taxa, questions regarding intrafamilial and intrageneric relationships remain unresolved. To address these gaps, we collected trigonostomids from the North Sea, the Mediterranean, and [...] Read more.

The rhabdocoel family Trigonostomidae has been the subject of recent phylogenetic revisions. However, due to the limited number of sequenced taxa, questions regarding intrafamilial and intrageneric relationships remain unresolved. To address these gaps, we collected trigonostomids from the North Sea, the Mediterranean, and the Atlantic Ocean, and examined them using an integrative approach. Nineteen specimens, representing ten species, were sequenced for phylogenetic analyses. Eight species were sequenced for the first time, including the first molecular data for Lutheriella. All genera were recovered as monophyletic; however, Ceratopera falcata (type species of Messoplana) and a new closely related species were found to cluster with species of Beklemischeviella, while the remaining species of Ceratopera formed a distinct clade. Based on these findings, we propose the resurrection of Messoplana, which had previously been synonymised with Ceratopera. Notably, genetic divergence and differences in the bursal mouthpiece between specimens of M. falcata suggest the possible presence of cryptic diversity or geographical isolation within this taxon. The inclusion of Trigonostomum breitfussi provided molecular support for its morphologically defined group. Furthermore, L. diplostyla was found to be closely related to species of Ptychopera. In addition to phylogenetic analyses, we describe four new species: Ceratopera bransoni sp. nov., Messoplana judithae sp. nov., Parapharyngiella scotti sp. nov., and Ptychopera woodyi sp. nov. The discussion of the new species of Parapharyngiella and Ptychopera motivated the reclassification of Pt. scutulifera as Pa. scutulifera comb. nov. We record for the first time eight species from Florida, seven from the Indian River Lagoon, and two from the Florida Keys National Marine Sanctuary, in the USA. This study refines the phylogenetic framework and internal classification of Trigonostomidae by providing new molecular evidence for previously unsampled taxa and by re-evaluating generic boundaries within the family. Full article

(This article belongs to the Special Issue Advances in Diversity, Evolutionary History and Ecology of Global Flatworms)

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19 pages, 8103 KB

Open AccessArticle

The Vertical Structure of Rich Fen Vegetation and the Development of Bryophyte Cover

by Monika Kalvaitienė and Ilona Jukonienė

Diversity 2026, 18(7), 434; https://doi.org/10.3390/d18070434 - 20 Jul 2026

Abstract

The vertical structure of fen vegetation has received little attention, despite its obvious relevance to interactions between herbaceous plants and bryophytes. The main objective of this study was to determine relationships among the vertical herbaceous-rich-fen vegetation structure and the overall cover and species [...] Read more.

The vertical structure of fen vegetation has received little attention, despite its obvious relevance to interactions between herbaceous plants and bryophytes. The main objective of this study was to determine relationships among the vertical herbaceous-rich-fen vegetation structure and the overall cover and species diversity of bryophytes. The study was conducted in eight fens in Lithuania and covered 210 subplots (0.5 m × 0.5 m). Within each subplot, the total and individual percentages of bryophyte and vascular plant cover, and of each visually distinct vertical vegetation layer, were estimated. In vertical vegetation structure, five distinct structural groups were identified, ranging from a simple two-layer group to a four-layer group. Vertical structural differences in herb cover were primarily associated with water level and microrelief. Our results revealed that an open structure is favourable for entire bryophyte cover; shading does not necessarily lead to a decline in total bryophyte cover but rather drives a structural rearrangement of the bryophyte community. The abundant development of higher vegetation layers in highly hummocky areas negatively affects the bryophyte cover. Monitoring visually distinct vertical structures can help predict negative trends in plant community structure, including shifts in bryophyte diversity and cover. Full article

(This article belongs to the Special Issue Wetland Biodiversity and Ecosystem Conservation—Second Edition)

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33 pages, 5403 KB

Open AccessArticle

Phylogenetic Inference via Ancestral State Reconstruction/Character Mapping Is Logically Unsound Abductive Reasoning

by Kirk Fitzhugh

Diversity 2026, 18(7), 433; https://doi.org/10.3390/d18070433 - 18 Jul 2026

Abstract

Ancestral state reconstruction (ASR) and the related method of character mapping (CM) have become increasingly popular, wherein it is claimed that phenotypic characters are causally accounted for by fitting those characters onto a phylogenetic tree previously inferred to explain sequence data. In this [...] Read more.

Ancestral state reconstruction (ASR) and the related method of character mapping (CM) have become increasingly popular, wherein it is claimed that phenotypic characters are causally accounted for by fitting those characters onto a phylogenetic tree previously inferred to explain sequence data. In this paper, I offer a unique critique of ASR/CM by addressing several relevant, interconnected conceptual issues that, in the scope of established deductive and non-deductive forms of reasoning applied in the process of scientific inquiry, show that ASR/CM are logically unsound methods that lead to erroneous conclusions. The problem, as outlined in this paper, rests largely on the fact that inferences of phylogenetic, as well as all other classes of systematic hypotheses, à la taxa, are instances of abductive reasoning. Abductive inferences involve the conjunction of a theory of cause–effect relations to observed effects in order to conclude a plausible hypothesized cause or set of causes. As a matter of non-deductive reasoning, it is shown that the requirement of total evidence (RTE) is relevant to abductive reasoning, at least in the context of inferring phylogenetic and specific (i.e., species) hypotheses. It is then shown that ASR/CM fail as forms of abductive reasoning for two reasons: (1) violation of the RTE, and (2) the methods include, as a premise, a previously inferred phylogenetic tree that has no logical relevance to the inference. The consequence is that ASR/CM necessarily lead to conclusions that cannot be interpreted as explanatory hypotheses. Full article

(This article belongs to the Section Phylogeny and Evolution)

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21 pages, 1179 KB

Open AccessArticle

Plant Collections of the E. Gareev Botanical Garden: Diversity and Characteristics

by Mira Mamytova, Aida Nurmanbetova, Medet Akhmatov, Galina Malosieva, Irina Popova, Leonid Andreychenko, Yaoming Li and Xuexi Ma

Diversity 2026, 18(7), 432; https://doi.org/10.3390/d18070432 - 17 Jul 2026

Abstract

The article presents the results of long-term research on plant introduction and the establishment of plant collections at the E. Gareev Botanical Garden of the National Academy of Sciences of the Kyrgyz Republic. The aim of the research was to preserve, expand, and [...] Read more.

The article presents the results of long-term research on plant introduction and the establishment of plant collections at the E. Gareev Botanical Garden of the National Academy of Sciences of the Kyrgyz Republic. The aim of the research was to preserve, expand, and comprehensively investigate the living plant collection of the E. Gareev Botanical Garden. Phenological, ontogenetic, and biological characteristics were examined, along with plant adaptation to the soil and climatic conditions of the Chui Valley. The living collection comprises 495 woody and shrub taxa (48 families, 121 genera), including 80 coniferous and 415 deciduous species. Notably, 63 native Kyrgyz taxa were identified, comprising 5 coniferous and 58 deciduous tree species, with 30 subendemics and 2 endemics. The herbaceous collection includes 57 native Kyrgyzstan species, of which 5 are endemic, 37 are subendemic, and 14 are listed in the Red Book of the Kyrgyz Republic. Additionally, 117 medicinal species and varieties were documented, with 48 species (41 genera, 15 families) representing the native flora. Species from the low-mountain valleys, foothills, and lower mountain belts exhibited the highest adaptation success, whereas high-mountain species showed comparatively lower establishment rates. These findings provide a scientific basis for optimizing ex situ conservation strategies and expanding the botanical garden’s collection through targeted introduction programs. Full article

(This article belongs to the Section Plant Diversity)

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9 pages, 1696 KB

Open AccessCommunication

Natural Versus Anthropogenic Dispersal of Freshwater Turtles Between the Baja California Peninsula and Mainland Mexico

by James F. Parham, Bryan L. Stuart, W. Brian Simison and Theodore J. Papenfuss

Diversity 2026, 18(7), 431; https://doi.org/10.3390/d18070431 - 17 Jul 2026

Abstract

Trachemys nebulosa is a freshwater turtle found on the Baja California Peninsula (BCP) and mainland northwestern Mexico. Two subspecies are recognized: Trachemys nebulosa nebulosa from the BCP and Trachemys nebulosa hiltoni from the mainland. Previous genetic studies found small differences between these taxa, [...] Read more.

Trachemys nebulosa is a freshwater turtle found on the Baja California Peninsula (BCP) and mainland northwestern Mexico. Two subspecies are recognized: Trachemys nebulosa nebulosa from the BCP and Trachemys nebulosa hiltoni from the mainland. Previous genetic studies found small differences between these taxa, but limited sampling left questions about their distinctiveness and origins. Most authors who have studied this species have invoked human-mediated transport to explain its distribution. To test this hypothesis, we combined previously published genetic data with expanded sampling. Mainland and peninsular populations did not share mitochondrial or nuclear sequences, and data from both genomes separated them into distinct groups. These results support retaining T. n. hiltoni and T. n. nebulosa as separate taxa and favor a natural dispersal from the BCP to the mainland, followed by isolation of mainland populations. Because T. n. hiltoni has a limited distribution and is harvested for food, recognizing it as a distinct lineage has conservation implications. Additional sampling, particularly from the Cape Region of the BCP, will help further test historical connections between mainland and peninsular populations. Full article

(This article belongs to the Special Issue Freshwater Turtles in Anthropogenic Landscapes)

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14 pages, 530 KB

Open AccessArticle

DNA Barcoding of Flesh Flies (Diptera: Sarcophagidae) in Jamaica: A Preliminary Assessment

by Latoya Foote-Gordon, Taneisha A. Barrett and Paula Tennant

Diversity 2026, 18(7), 430; https://doi.org/10.3390/d18070430 - 17 Jul 2026

Abstract

The Caribbean is a recognized biodiversity hotspot; however, on islands such as Jamaica, many faunal groups of ecological and forensic importance, including flesh flies, remain poorly characterized, particularly at the genetic level. This study represents an initial step towards addressing that gap through [...] Read more.

The Caribbean is a recognized biodiversity hotspot; however, on islands such as Jamaica, many faunal groups of ecological and forensic importance, including flesh flies, remain poorly characterized, particularly at the genetic level. This study represents an initial step towards addressing that gap through DNA barcoding. Forty-four specimens from 16 species were analyzed through partial sequencing of the cytochrome c oxidase subunit I (COI) gene. Of the 44 sequences, 30% shared 97–100% similarity with reference sequences in GenBank and BOLD; however, taxonomic resolution varied between databases. The remaining sequences gave lower similarity matches (88–96%), with assignments restricted to the genus level or higher taxonomic ranks, or were discordant with morphology-based identifications. With one exception, pairwise intraspecific genetic distances were low (0.17%), whereas interspecific distances ranged from 5.68% to 12.83%. Neighbor-joining analysis showed that Jamaican taxa, including five endemic species and two new records, formed largely distinct monophyletic clades relative to sequences from North and South America, Europe and Oceania, with >70% bootstrap support. These findings demonstrate the utility of COI barcoding for species discrimination among Jamaican flesh flies and represent an important step towards establishing a regional DNA barcode library. Expanding Caribbean representation in global databases will be essential for improving the accuracy of molecular identification and resolving uncharacterized taxa. Full article

(This article belongs to the Section Animal Diversity)

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21 pages, 1663 KB

Open AccessArticle

Citizen-Science Data Reveal Global Diversity Patterns in the Gecko Genus Hemidactylus

by Muammer Kurnaz, Ahmet Ali Berber and Cansu Akbulut

Diversity 2026, 18(7), 429; https://doi.org/10.3390/d18070429 - 17 Jul 2026

Abstract

Understanding how species richness is distributed across space is a central goal of macroecology and biogeography. The gecko genus Hemidactylus ranks among the most speciose and broadly distributed of all squamate genera, with species spanning tropical and subtropical environments on most continents. Yet [...] Read more.

Understanding how species richness is distributed across space is a central goal of macroecology and biogeography. The gecko genus Hemidactylus ranks among the most speciose and broadly distributed of all squamate genera, with species spanning tropical and subtropical environments on most continents. Yet the large-scale structure of its diversity has rarely been examined at a global scale. Here we assembled georeferenced occurrence data for the genus from the Global Biodiversity Information Facility (GBIF Access data is 14 March 2026) and, following cleaning and quality control, retained 143,858 records covering 157 currently recognized species (approximately 79% of the genus) to characterize broad-scale biodiversity patterns. Our analyses addressed the latitudinal diversity gradient, the distribution of species range sizes, continental richness, spatial clustering of diversity, and regional beta diversity. Richness declined steadily from the tropics toward the poles, producing a pronounced latitudinal diversity gradient (Pearson r = −0.71, p < 0.001). A generalized additive model captured a strong non-linear association between latitude and richness (deviance explained = 98.1%), consistent with tropical regions acting as principal centers of diversity. Range-size distributions were markedly right-skewed, with the majority of species restricted to comparatively small areas; however, these estimates co-varied strongly with per-species sampling effort (r = 0.90) and warrant cautious interpretation. We found only a weak, marginally significant association between range size and latitudinal midpoint, offering little support for Rapoport’s rule in the genus. At the continental scale, Hemidactylus diversity was overwhelmingly concentrated in Afro-Asian tropical regions (Asia, 93 species; Africa, 66), whereas Europe and Oceania supported few species (four each). Spatial analyses indicated significant autocorrelation in richness (Moran’s I = 0.56, p < 0.001) and well-defined diversity hotspots in East Africa, the Indian subcontinent, and Southeast Asia, and regional beta diversity was high (Jaccard dissimilarity up to 0.97), reflecting pronounced faunal turnover among continents. Full article

(This article belongs to the Topic Intersection Between Macroecology and Data Science)

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15 pages, 7396 KB

Open AccessArticle

Floristic Diversity, Vegetation Structure, and Ontogenetic Composition of Sibiraea altaiensis (Rosaceae) Populations in the Kazakhstan Altai

by Anar Myrzagaliyeva, Aidyn Orazov, Talant Samarkhanov, Serik Irsaliyev, Zhanylkan Alemseitova and Shynar Tustubayeva

Diversity 2026, 18(7), 428; https://doi.org/10.3390/d18070428 - 16 Jul 2026

Abstract

The taxonomic status of the Altai populations traditionally identified as Sibiraea altaiensis remains unresolved, with international databases generally treating the name as a synonym of S. laevigata. At the same time, regional sources retain it for conservation and floristic purposes. Using S. [...] Read more.

The taxonomic status of the Altai populations traditionally identified as Sibiraea altaiensis remains unresolved, with international databases generally treating the name as a synonym of S. laevigata. At the same time, regional sources retain it for conservation and floristic purposes. Using S. altaiensis as an operational regional name, we established a comparative ecological baseline for six natural populations distributed across the Southern and Western Kazakhstan Altai at 814–2130 m a.s.l. Vegetation was surveyed in July 2024 and July 2025 in ten 10 m × 10 m plots per population using complete vascular plant inventories, Braun–Blanquet abundance–dominance estimates, descriptions of vertical structure, and field assessment of shrub ontogenetic states. Observed vascular plant richness ranged from approximately 35 species at Tautekeli to 78 at Lineinsky; Shubartoc and Ridder contained 76 and 72 species, respectively. Mesophytes constituted 56.3–77.0% of the population floras, demonstrating a predominantly mesic community affinity across contrasting subalpine slopes, river terraces, floodplains, and sparse conifer forest. Sibiraea altaiensis was dominant or structure-forming at every locality, although associated species composition and vegetation architecture varied substantially among habitats. Juvenile plants were not detected at five populations, whereas their occurrence at Lineinsky was insufficiently documented for comparison; this pattern is interpreted cautiously because dense midsummer vegetation and litter may reduce seedling detectability. Floristic richness did not conform to a simple Southern-versus-Western Altai division, indicating that local habitat heterogeneity and vegetation context may be more informative than regional position alone. The study provides a verified descriptive baseline and identifies permanent plot monitoring, early-season recruitment surveys, direct environmental measurements, and integrated molecular taxonomic analyses as priorities for conservation assessment. Full article

(This article belongs to the Section Plant Diversity)

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18 pages, 6521 KB

Open AccessArticle

Early Changes in Soil Organic Carbon Following Ecological Restoration in Mangroves Invaded by Acrostichum aureum

by Julio César Chávez-Barrera, Juan Fernando Gallardo-Lancho, Carlos Armando Chan-Keb, Margarita Elizabeth Gallegos Martínez, Ana Carolina Ruiz-Fernández, Robert Puschendorf and Claudia Maricusa Agraz-Hernández

Diversity 2026, 18(7), 427; https://doi.org/10.3390/d18070427 - 16 Jul 2026

Abstract

Mangrove ecosystems store large amounts of soil organic carbon (SOC). However, degradation processes associated with invasive species can alter vegetation structure, hydrological conditions, and carbon cycling, with uncertain consequences for SOC storage and greenhouse gas emissions. This study evaluated changes in SOC stocks [...] Read more.

Mangrove ecosystems store large amounts of soil organic carbon (SOC). However, degradation processes associated with invasive species can alter vegetation structure, hydrological conditions, and carbon cycling, with uncertain consequences for SOC storage and greenhouse gas emissions. This study evaluated changes in SOC stocks to 0–50 cm depth, soil CO₂, CH₄, and N₂O fluxes, and early restoration responses four years after ecological restoration in the Térraba–Sierpe National Wetland, Costa Rica. Comparisons were conducted among a conserved mangrove, a degraded mangrove dominated by Acrostichum aureum, and three restored sites subjected to hydrological rehabilitation with contrasting reforestation intensities. The degraded site showed significantly higher SOC contents (171 ± 31 Mg C ha⁻¹; p < 0.0001) compared to the conserved site (103 ± 26 Mg C ha⁻¹). CO₂ fluxes did not differ significantly between March and October. CH₄ and N₂O fluxes remained below the detection limits in most measurements. Redundancy analysis identified a significant association between vegetation composition and the measured environmental variables (p = 0.005). Higher CO₂ emissions were associated with the dominance of A. aureum. Plant density was positively related to SOC content (R² = 0.78). MR1 site, where hydrological rehabilitation was combined with high-density reforestation, had significantly higher SOC content than the degraded site (242 ± 24.3 Mg C ha⁻¹; p < 0.001). Soil CO₂ emissions at MR1 were also significantly lower than at the degraded site (p = 0.001). This study provides a pioneering field assessment of mangrove restoration through the control of A. aureum invasion. The results suggest that restoration design may influence soil carbon storage during the early stages of recovery. Full article

(This article belongs to the Special Issue Biodiversity and Ecosystem Conservation of Coastal Wetlands)

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5 pages, 176 KB

Open AccessReply

Reply to Galil, B.S.; Rinkevich, B. Comment on “Kuplik et al. Rhopilema nomadica in the Mediterranean: Molecular Evidence for Migration and Insights into Its Proliferation. Diversity 2026, 18, 94”

by Zafrir Kuplik, Hila Dror, Karin Tamar, Alan Sutton, James Lusana, Blandina Lugendo and Dror L. Angel

Diversity 2026, 18(7), 426; https://doi.org/10.3390/d18070426 - 16 Jul 2026

Abstract

We thank Galil and Rinkevich for their interest in our recent publication [...] Full article

3 pages, 149 KB

Open AccessComment

Comment on Kuplik et al. Rhopilema nomadica in the Mediterranean: Molecular Evidence for Migration and Insights into Its Proliferation. Diversity 2026, 18, 94

by Bella S. Galil and Baruch Rinkevich

Diversity 2026, 18(7), 425; https://doi.org/10.3390/d18070425 - 16 Jul 2026

Cited by 1

Abstract

Based on COI analyses of three medusae collected in Dar es Salaam, Tanzania, and on a low-resolution photograph of a jellyfish swarm in Haifa Port, Kuplik et al. [...] Full article

(This article belongs to the Section Marine Diversity)

16 pages, 13845 KB

Open AccessArticle

A Study on the Taxonomic, Functional, and Phylogenetic Diversity of Plants in the Gurbantunggut Desert

by Xinyi Lin, Lin Han, Yong Zeng, Gulmira Nurmaimaiti, Dandan Wang and Peng Wang

Diversity 2026, 18(7), 424; https://doi.org/10.3390/d18070424 - 15 Jul 2026

Abstract

Understanding the mechanisms that sustain plant diversity in arid regions is a current focus of ecological research. This study focused on the Gurbantunggut Desert, China’s largest fixed and semi-fixed desert, and systematically investigated the plant community diversity and its environmental drivers on fixed, [...] Read more.

Understanding the mechanisms that sustain plant diversity in arid regions is a current focus of ecological research. This study focused on the Gurbantunggut Desert, China’s largest fixed and semi-fixed desert, and systematically investigated the plant community diversity and its environmental drivers on fixed, semi-fixed, and mobile dunes. Data analysis was conducted using non-metric multidimensional scaling (NMDS) ordination, redundancy analysis (RDA), boosted regression tree (BRT), and structural equation modeling (SEM). The results indicated that taxonomic diversity (TD), functional diversity (FD), and phylogenetic diversity (PD) all exhibited consistent gradient patterns: fixed dunes > semi-fixed dunes > mobile dunes. The Net Relatedness Index (NRI) and the Nearest Taxon Index (NTI) primarily exhibited phylogenetic clustering, and habitat filtering was the dominant process in community assembly. Soil water content (SWC) and soil organic carbon (SOC) are the key drivers regulating plant diversity in this region. SWC and SOC directly and significantly influence FD and PD; however, their indirect effects on TD are weak, suggesting that species composition is also jointly constrained by abiotic processes such as dispersal limitation and interspecific competition. This study offers a theoretical foundation for differentiated ecological management of fixed, semi-fixed, and mobile dunes in the Gurbantunggut Desert. Full article

(This article belongs to the Section Plant Diversity)

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20 pages, 6618 KB

Open AccessArticle

Mountaintop-Extinction Risk for Polylepis tarapacana: An Elevational-Ceiling and No-Escape Framework in the South-Central Andes

by Javier Quille-Mamani, Raul Uscamayta, German Huayna-Felipe, Pablo Franco-León, Fredy Cabrera-Olivera, Bertha Vera-Barrios, José Huanuqueño-Murillo, Marco Navarro and Edwin Pino-Vargas

Diversity 2026, 18(7), 423; https://doi.org/10.3390/d18070423 - 15 Jul 2026

Abstract

Sustained warming is displacing montane species upslope, yet trees already at the upper limit of their mountains face a finite vertical refuge. This study assessed whether the world’s highest-elevation tree, Polylepis tarapacana, can remain within climatically suitable terrain as the climate warms [...] Read more.

Sustained warming is displacing montane species upslope, yet trees already at the upper limit of their mountains face a finite vertical refuge. This study assessed whether the world’s highest-elevation tree, Polylepis tarapacana, can remain within climatically suitable terrain as the climate warms across its South-Central Andean range (Peru, Bolivia, Chile, and Argentina), with field validation in Tacna, southern Peru. The aim was to quantify, under CMIP6 scenarios extending to 2100, how much suitable habitat the species retains and what fraction of any loss leaves no reachable higher-elevation refuge. A MaxEnt model, benchmarked against Random Forest, was calibrated on the full known range from GBIF occurrences and field plots using collinearity-filtered bioclimatic predictors and a sampling-bias-corrected background, projected as a multi-GCM ensemble under CMIP6 twenty-first-century scenarios, and validated externally against 148 field-mapped stand polygons (12,874 ha). A novel elevational-ceiling and “no-escape” framework quantified, for each scenario, the suitable area lost without any reachable higher-elevation refuge. The models discriminated suitable habitat well (external AUC

= 0.85

, Boyce

= 0.98

). Under the highest-emission pathway, suitable habitat in Tacna contracts from

- 13 %

(2030s) to

- 100 %

(2090s) and the highly suitable class collapses by

99.4 %

; across the partial-loss scenarios, the suitability centroid shifts upslope by up to

+ 195

m. By 2081–2100 the no-escape fraction reaches

100 %

at every tested dispersal buffer—to date the first quantitative evidence of mountaintop-extinction risk for the world’s highest-elevation tree. These results argue for anticipatory ex situ conservation and Peru–Bolivia cross-border protection of the highest-elevation Altiplano refugia, before the vertical escape route closes. Full article

(This article belongs to the Section Biogeography and Macroecology)

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