Biogeographic Units Research Articles

In a niche-neutral continuum, a set of theoretical models in a metacommunity operates simultaneously in patchy habitats.

This study investigated the origins and maintenance of biodiversity by integrating ecological and evolutionary mechanisms into a spatially-explicit synthesis between niche-based processes and neutral dynamics (ND). An individual-based model on a two-dimensional grid with periodic boundary conditions was used to compare a niche-neutral continuum induced in contrasting spatial and environmental settings while characterizing the operational scaling of deterministic-stochastic processes. The spatially-explicit simulations revealed three major findings. First, the number of guilds in a system approaches a stationary state and the species composition in a system converges to a dynamic equilibrium of ecologically-equivalent species generated by the speciation-extinction balance. This convergence of species composition can be argued under a point mutation mode of speciation and niche conservatism due to the duality of ND. Second, the dispersal modes of biota may affect how the influence of environmental filtering changes across ecological-evolutionary scales. This influence is greatest in compactly-packed areas within biogeographic units for large-bodied active dispersers, such as fish. Third, the species are filtered along the environmental gradient and the coexistence of ecologically-different species in each local community in a homogeneous environment is allowed by dispersals in a set of local communities. Therefore, the ND among the single-guild species, extinction-colonization trade-off among species of similar environmental optima and different levels of specialization, and mass effect, such as weak species-environment associations, operate simultaneously in patchy habitats. In spatially-explicit synthesis, characterizing where a metacommunity falls along a niche-neutral continuum is too superficial and involves an abstraction that any biological process is probabilistic; therefore, they are dynamic-stochastic processes. The general patterns observed in the simulations allowed a theoretical synthesis of a metacommunity and explained the complex patterns observed in the real world.

Mitochondrial DNA sequences and nuclear microsatellites reveal population genetic structure of the range-restricted hummingbird Phaeoptila sordida in the Balsas Basin

Abstract The Dusky Hummingbird Phaeoptila sordida (= Cynanthus sordidus), occurs in the Balsas Basin, a region with a complex biogeographical history, and in the Tehuacán-Cuicatlán Valley and Valles Centrales in Puebla and Oaxaca, Mexico. However, the biogeographical and evolutionary history of these two regions of Mexico is poorly understood. We aimed to understand the genetic structure and phylogeographic history of P. sordida, a range-restricted hummingbird to these two regions, as a proxy to study the evolutionary history of the Balsas Basin, by using mitochondrial DNA (mtDNA) sequences and nuclear microsatellites. Geographic structure was evident for both markers; however, some discordance was observed between the mitochondrial and nuclear markers. Based on mtDNA, samples from the Balsas Basin form one haplogroup, well separated from the Tehuacán-Cuicatlán Valley and Valles Centrales samples. In contrast to this, nuclear microsatellites uncovered two slightly different genetic clusters restricted to different habitats: samples from the Western Balsas restricted to the seasonally deciduous tropical dry forest, and samples from the Eastern Balsas-Tehuacán/Cuicatlán-Tehuantepec area in shrub and dry forested habitats. As expected by the interglacial refugia hypothesis, ENM predicted that the distribution of P. sordida was more contracted and fragmented during the Last Inter Glacial and more expanded at the Last Glacial Maximum. Consistent with that observed for other range-restricted hummingbird species, ENM predictions and a strong signal of population expansion indicate that the geographical range and population size are unstable over time, as compared to widespread hummingbird species, and that ecological and climatic factors possibly impacted its diversification. This study contributes to the debate that disputes the integrity of the Balsas Basin as a biogeographical unit and urges for the conservation of endemic species in the Balsas region and interior Oaxaca.

A Conceptual Framework for Conservation and Management of Moroccan Forest Genetic Resources Using Biogeography-Based Approach

The introduction of mal-adapted genotype is a major concern in conservation and management of forest genetic resources. This is risky because it potentially threatens the integrity of the natural genetic structure of populations. Therefore, it is necessary to provide guidance on the choice of appropriate germplasm and determine how far it can be moved from its native environment. The most basic guidelines for germplasm movement involve the use of Regions of Provenance (RoP). The RoP for a forest species or sub-species is the area or group of areas subject to sufficiently uniform ecological conditions in which stands or seed sources showing similar phenotypic or genetic characters are found, taking into account altitudinal boundaries where appropriate. However, there is little information concerning Regions of Provenance and limited knowledge about safe limits to the movement of seed, cuttings and planting stock in Morocco. This paper establishes a conceptual framework based on Regions of Provenance that is designed to better understand, protect and use forest genetic resources in Morocco, especially the species for which no specific knowledge on local adaptation or no data about population differentiation are currently available. This is the first study that represents a precise map of Regions of Provenance for Moroccan forest reproductive material and that provides detailed description on topographical, environmental and forest characteristics that characterize each Region of Provenance, by using geographical information system (GIS) techniques. A biogeography-based approach was applied and revealed that the territory was hierarchically organized into 2 Biogeographic Divisions, 9 Biogeographic Units and 19 Regions of Provenance. The RoP proposed are intended as a practical provenance decision-making tool to guide the movement of forest reproductive material in Morocco. This ensures the traceability of planting stock throughout the harvesting-seedling production-plantation process to a specified Forest Basic Material.

Sixty-seven species newly recorded for the flora of Angola: recent findings from vegetation surveys and herbarium collections

Angola is a tropical country with many biogeographical units and, therefore, has a high floristic diversity. Although an increasing number of floristic studies has been carried out in Angola in recent years, the country is still considered to be underinvestigated as many species being collected were previously unknown there. Several scientific groups working in different parts of Angola contributed to this paper their data from biodiversity assessments. With this we can add 67 species newly recorded for Angola, including two new generic records and five alien species, to the almost 7,300 vascular plant taxa known so far for Angola. Most of the new records for Angola are also present in different neighbouring countries, but they are little known, and their IUCN threat status has not been assessed yet. However, ongoing fieldwork and exploration are needed to complete the floristic knowledge of the understudied country.

BOVEDA, the Bolivian Vegetation Ecology Database: first stage, the Chacoan forests

Bolivia is a country exceptionally rich in biodiversity and home to about 20,000 vascular plant species and 15 plant formations. Therefore, it is particularly important to document the biodiversity of this territory. The aim of the Bolivian Vegetation Ecology Database (BOVEDA; GIVD ID SA-BO-005) is to record floristic and ecological data of Bolivian vegetation. In the first stage, the database hosts 320 relevés from one of the most unique biogeographical units in the country, the Chaco. In total, 633 species belonging to 114 families have been recorded. Data on vegetation structure, soil, flooding regime and geomorphology have also been stored. The following nine vegetation structural types were identified: (1) deciduous forests of alluvial plains on well to moderately well drained soils; (2) deciduous to semideciduous Chaco forests transitional to the Andes; (3) deciduous and sclerophyllous Cerrado thorn-woodlands and shrublands transitional to the Chaco (Abayoy); (4) xeromorphic thorn shrubland and thickets on vertic, poorly drained soils; (5) woodlands and savannas on sand dunes and aeolian surfaces; (6) freshwater swamp forests; (7) saltwater swamp forests; (8) phreatophytic forests; (9) deciduous to semideciduous Chaco forests transitional to the Chiquitania. Further steps will be to incorporate new types of vegetation already recorded in the field such as Altiplano shrublands, Andean wetlands, Andean Polylepis forests, and vegetation of the dry inter-Andean valleys. Taxonomic reference: Jørgensen et al. (2015). Abbreviations: BOVEDA = Bolivian Vegetation Ecology Database; GIVD = Global Index of Vegetation-Plot Databases.

A phytogeographic assessment of the Sierra Madre Oriental physiographic province, Mexico

Background: Different regionalizations have been proposed for the Sierra Madre Oriental (SMOR), but none of them have analyzed its full floristic diversity.
 Hypothesis: The geographical distribution of the vascular plant species of the SMOR allows the identification of floristic regions with unique species that identify them as biogeographic units.
 Studied species: Vascular plants.
 Study site: Sierra Madre Oriental physiographic province, Mexico.
 Methods: Plant species distribution was analyzed in 1 × 1° latitude and longitude grid cells. Characteristic species (those with half or more of their known geographical distribution in Mexico in the SMOR) were identified, and a classification method was applied to distinguish biogeographic regions.
 Results: 8,472 species were recorded in the Sierra Madre Oriental, 3,433 of them considered characteristics, of which 2,158 are endemic to Mexico and 585 are considered strictly endemic to the province. The portions of the SMOR in the states of Coahuila, Nuevo León, Tamaulipas, and San Luis Potosí have a higher species richness and this richness decreases towards the south of the province. Five floristic districts were identified within the SMOR.
 Conclusions: The phytogeographic analysis carried out and its comparison with other regionalizations shows there is still disagreement in the biogeographic delimitation of the Sierra Madre Oriental and to achieve this goal it is necessary to include neighboring provinces in the analyzes, which will allow to identify their unique species and define their biogeographic limits in a more precise way.

Delineating biogeographic regions in Indian Ocean deep‐sea vents and implications for conservation

AbstractAimThe pattern of biodiversity and biogeography is crucial to informing management and conservation strategy. But a lack of study across multiple ridge systems, especially for the Carlsberg Ridge, has hampered the conception of the overall picture for the Indian Ocean vents, a top target for deep‐sea exploration of massive sulphides. Here, we aim to characterize fauna from three new vent fields on the Carlsberg Ridge for the first time, and answer 1) what is the biogeographic pattern for vent fauna within the Indian Ocean and 2) how does this pattern guide the future environmental management on the Indian Ocean ridges.LocationVents on the Carlsberg Ridge (CR), Central Indian Ridge (CIR), and Southwest Indian Ridge (SWIR).TaxonMacrofauna.MethodsSamples, still images and videos were collected from vent fields by either submersible or TV‐guided grab. A comprehensive dataset of 11 fields on Indian Ocean ridges were obtained based on taxa identification and compilation. Genetic connectivity was analysed for six species using COI sequences. A framework for identifying biogeographic regions based on beta diversity measurement βsim was employed to reveal species turnover along the Indian Ocean ridges.ResultsFaunal assemblages at three new vents on the CR hosted a total of 34 species. Significant genetic differentiation was detected between southern SWIR and CIR (plus Tiancheng) for three species, and between CIR (plus Tiancheng) and CR for four species. Hierarchical clustering of βsim support division of the Indian Ocean vents into three clades.Main conclusionsSpecies turnover along the ridges supported the separation of Indian Ocean vents into three discrete biogeographic units, boundaries between which largely corresponded to genetic breaks for shared species with lower dispersal capabilities. The results clearly show that the conservation of Indian Ocean vents must target three provinces, simultaneously.

Geographic distribution patterns of amphibians and reptiles from the Uruguayan Savanna

We assessed the geographic distribution of amphibians and reptiles occurring in the Uruguayan Savanna ecoregion (USE) to find shared distribution patterns, in order to identify chorotypes which could inform the conflicting regionalization of the Pampa province. We compiled nearly 83,000 records of complete geographic distributions of the 58 species of amphibians and 86 species of reptiles with occurrence in the Uruguayan Savanna throughout South America. Endemicity analysis (NDM/VNDM) was implemented to identify shared geographic distribution patterns (chorotypes). We described general diversity patterns for the Uruguayan Savanna in terms of endemic species and the degree of species shared with other ecoregions. We have found five amphibians (anurans) and nine reptiles (six lizards, two amphisbaenians, and one snake) endemic to the USE, while most species from the Uruguayan Savanna ecoregion are shared with other ecoregions. We recovered 38 consensus areas from 68 individual areas resulting in 17 chorotypes after implementing a metaconsensus cluster analysis. Our results indicate a complex pattern of shared geographic distributions between Uruguayan Savanna and adjacent biogeographical units. The limits of the ecoregion coincided with some chorotypes, however, the traditional limits of the Pampa did not align with any chorotype. The tropical affinity of the USE was supported by both the number of species shared with Alto Paraná Atlantic forests, and the pattern of chorotype recovered. Species that occur in temperate pampa and the USE were widely distributed in other ecoregions.

A new late Pliocene toad of the genus Rhinella (Bufonidae) from northwestern Argentina

The best known Neotropical fossil bufonid discovered to date is described herein. This material includes well-preserved cranial and postcranial disarticulated remains that were part of a microvertebrate fossil assemblage generated by the accumulation of predatory bird pellets. The remains were recovered from the Middle Unit of the Uquía Formation (late Pliocene) that crops out next to the locality of Humahuaca, Jujuy Province, northwestern Argentina. In this contribution, we present a detailed osteological description of this taxon and compare the morphological characters with respect to other related members of the large genus Rhinella. Several distinctive character states present in these fossil remains allows us to refer to them as part of a new species of the Andean R. spinulosa Group. The new species described here together with the fossil marsupials and sigmodontines rodents suggest that by the late Pliocene, the Uquía area, the Andean region of Bolivia, and southern Peru were part of the same biogeographic unit.

Distribution patterns of Triatominae (Hemiptera: Reduviidae) in the Americas: an analysis based on networks and endemicity.

Triatominae, commonly known as kissing bugs, are a group of approximately 150 species of hematophagous reduviids, some of which are vectors of Trypanosoma cruzi, the etiological agent of the Chagas disease. Distributional patterns of triatomines have been studied based on macroecological and historical biogeographic approaches, but the definition of distributional patterns and areas of endemism are yet to be defined based on objective criteria. We used two methods to identify biogeographic units in the Triatominae: the endemicity analysis based on an optimality criterion (NDM/VNDM software) and a network approach aimed to simplify and highlight the underlying structure in species distributions (Infomap Bioregions). Information on species distributions was obtained from a data paper, comprising 21 815 records for 135 triatomine species occurring in the Americas. The resulting areas of each method were clustered using a meta consensus criterion based on dissimilarities and interpreted as recurrent areas. The NDM areas show a nested structure, presenting greater restrictions to the inclusion of species in a given area, requiring broad sympatry. In contrast, bioregions emphasize spatial patterns with better-delimited areas and species occurrences do not need to be highly congruent. When areas were clustered based on their species composition two clear patterns arose from both methods: (i) areas within the southern Amazon and southeast South America, especially in the Chacoan subregion, formed a cluster, and (ii) areas north of the Amazon, Pacific, Mesoamerica, Mexican transition zone and Nearctic formed another cluster. Moreover, within each of these two clusters, there was a latitudinal gradient of the areas in the Americas showing spatial similarity between the areas found in both methods. Results of both methods show well-bound areas separating the triatomine fauna in the Brazilian subregions, resulting in the recognition of areas corresponding to the biomes Chaco, Pampa, Cerrado, and Caatinga, and, to a lesser extent, the Atlantic Forest.

A biogeographical study of red listed lichen species at temporal and spatial scales within protected and non-protected areas

The present study is focused on the temporal and spatial distribution of red listed lichen (RLL) species identified in both non-protected areas (NPAs) and protected areas (PAs) in Romania. This study revealed different scenarios of RLL based on two major patterns: (1) the fate of RLL before and after their designation in the red list in Romania and (2) the fate of RLL before and after the designation of PAs in Romania. Generally, the occurrences of RLL were well represented in time and space in both NPAs and PAs through geomorphological and biogeographical units. In particular, the occurrences of RLL were well represented, especially in hilly areas within PAs before and after their official designation, and this was an important aspect over a long period of time. Although NPAs were not less important regarding the occurrences of RLL species, it was observed that they followed the same pattern as PAs, namely, they were well represented in hilly areas and over a long period of time. The bioregions were significant for RLL species in both NPAs (continental and stepic) and PAs (continental, panonic, and stepic). As a significant finding of this study, NPAs and PAs should be subjected to an adequate conservation regime due to their biotical traditional heritage.

The new Checklist of the Italian Fauna: Ascidiacea

We present a data set reporting the checklist of the species belonging to the class Ascidiacea for the 9 Italian marine biogeographical units, updating the one previously published by Mastrototaro & Tursi in 2010. In detail, the updated checklist includes 138 taxa at species level (66 Aplousobranchia, 30 Phlebobranchia and 42 Stolidobranchia). Records refer to various marine habitats, including lagoons, harbours and semi-enclosed environments as well as deep habitats. The previous checklist reported 129 taxa (66 Aplousobranchia, 27 Phlebobranchia and 36 Stolidobranchia): in detail, 12 species were added, of which four newly described species, seven non-indigenous species and a new record for the Italian waters. On the other hand, three species reported in the previous checklist were removed: two because currently considered dubious, and one because its occurrence in the Mediterranean Sea is not actually confirmed. Finally, two species were renamed because they are considered synonyms of older ones and five species are currently accepted with new combinations. In addition, five species expanded their biogeographic distribution. The checklist data set will be dynamically updated with new records, and it will be freely available from Lifewatch Italy at https://www.lifewatchitaly.eu/en/initiatives/checklist-fauna-italia-en/checklist. This note describes the state of the art of the Ascidian checklist data set until February 2022.  

Remote sensing and the UN Ocean Decade: high expectations, big opportunities

Remote sensing and the UN Ocean Decade: high expectations, big opportunities

Accelerated shifts in terrestrial life zones under rapid climate change.

Rapid climate change is impacting biodiversity, ecosystem function, and human well-being. Though the magnitude and trajectory of climate change are becoming clearer, our understanding of how these changes reshape terrestrial life zones-distinct biogeographic units characterized by biotemperature, precipitation, and aridity representing broad-scale ecosystem types-is limited. To address this gap, we used high-resolution historical climatologies and climate projections to determine the global distribution of historical (1901-1920), contemporary (1979-2013), and future (2061-2080) life zones. Comparing the historical and contemporary distributions shows that changes from one life zone to another during the 20th century impacted 27million km2 (18.3% of land), with consequences for social and ecological systems. Such changes took place in all biomes, most notably in Boreal Forests, Temperate Coniferous Forests, and Tropical Coniferous Forests. Comparing the contemporary and future life zone distributions shows the pace of life zone changes accelerating rapidly in the 21st century. By 2070, such changes would impact an additional 62million km2 (42.6% of land) under "business-as-usual" (RCP8.5) emissions scenarios. Accelerated rates of change are observed in hundreds of ecoregions across all biomes except Tropical Coniferous Forests. While only 30 ecoregions (3.5%) had over half of their areas change to a different life zone during the 20th century, by 2070 this number is projected to climb to 111 ecoregions (13.1%) under RCP4.5 and 281 ecoregions (33.2%) under RCP8.5. We identified weak correlations between life zone change and threatened vertebrate richness, levels of vertebrate endemism, cropland extent, and human population densities within ecoregions, illustrating the ubiquitous risks of life zone changes to diverse social-ecological systems. The accelerated pace of life zone changes will increasingly challenge adaptive conservation and sustainable development strategies that incorrectly assume current ecological patterns and livelihood provisioning systems will persist.

Mid-Pleistocene Transition as a trigger for diversification in the Irano-Anatolian region: Evidence revealed by phylogeography and distribution pattern of the eastern three-lined lizard

Past climatic events are one of the major drivers for divergence of species that could shape the present biodiversity and species dispersal patterns. Irano-Anatolian region is one of the biodiversity hotspots in the world. This region is predicted to serve various refugia during Quaternary glaciations. The eastern three-lined lizard ( Lacerta media media ) is a medium-sized lacertid species, which is originated from central Anatolian and is currently distributed almost across Irano-Anatolian region. In this study, the phylogeography, demographic history of the subspecies using mtDNA genes (cyt b , 12S and 16S) along with the species distribution models (SDMs) under past-present-future scenarios have been investigated. The results revealed that four distinct clades are well-established within the L. m. media which may intensely diverge during Pleistocene climatic fluctuations since the Mid-Pleistocene Transition (MPT). The past climate oscillations may isolate the population in various refugia throughout the Irano-Anatolian region which has been led to this divergence. The results of SDMs also indicates several localities with suitable climate conditions for eastern three-lined lizard in the region since LGM (21 thousand years ago) until the current date. This suitability can be expanded under future climate scenarios considering the existence of various low and high altitude refugia. Some conservation implications arise from the results that emphasize the importance of the region and its multiple refugia in preserving biodiversity. It can be suggested that, future conservation practices should be focused on the obtained biogeographical units such as central Anatolia, west and northwestern Iran, which encompass high levels of diversity including distinct clades within the eastern three-lined lizard.

The fish family Muraenidae: an ideal group for testing at small-scale the coherency of Macaronesia as a biogeographic unit, with the first report on separate fishery statistics

The present study was conceptualized to study the muraenid species (moray eels) occurring around the volcanic archipelagos of the Azores, Madeira, Selvagens, Canary and Cabo Verde islands (eastern-central Atlantic). The biogeographic patterns of these species were analysed and compared. We then hypothesized that this fish family is an ideal group for testing at small-scale the coherency of Macaronesia and its direct biogeographic units: i.e. the Azores, Webbnesia and Cabo Verde, as proposed in recent scientific literature. Additionally, this paper provides for the first time separate fishery statistics for this group in the region that were analysed to contrast the biogeographic results.

Between sand, rocks and branches: an integrative taxonomic revision of Angolan Hemidactylus Goldfuss, 1820, with description of four new species

Abstract The taxonomy of Angolan Hemidactylus has recently been revised. However, the lack of fresh material for some groups and regions, has led to the misidentification of some taxa and an underestimation of actual diversity in others. To shed light on the evolutionary history and systematics of Angolan Hemidactylus, we generated a new phylogenetic hypothesis for the group, and updated the taxonomy following an integrative approach. This resulted in the description of four new species (H. pfindaensissp. nov., H. faustussp. nov., H. carivoensissp. nov. and H. cinganjisp. nov.), the reevaluation of two recently described species (H. vernayi and H. paivae) and the synonymization of a recently described species (H. hannahsabinnae). We estimate divergence times for these lineages, providing a preliminary interpretation of their speciation process. Moreover, we suggest and outline 13 Angolan Main Biogeographic Units (AMBUs) in the area, defining a new biogeographic context for future works on Angolan herpetofauna. We now recognize eleven Hemidactylus species in Angola, and we provide here a new morphological key for Angolan Hemidactylus to help with identifications and species assignments in this group.

Ordovician conodont biostratigraphy, diversity and biogeography in deep-water radiolarian cherts from Kazakhstan

Studies of conodonts from the ribbon-banded radiolarian cherts and siliceous siltstones in the Burubaital Formation in the Buruntau area (SW Balkhash region, Kazakhstan) made it possible to characterize the conodont fauna from deep-water environments in the Ordovician. The conodont assemblages from chert successions at times of high diversity document at least 53 taxa (39 species and 14 taxa identified in open nomenclature) for the entire Ordovician. Conodont biodiversity in the Floian and lower Darriwilian is comparable to the diversity of conodonts inhabiting the neritic zone of epicontinental basins and continental shelves. In the Dapingian and from the middle Darriwilian to the end of the Ordovician, the taxonomic diversity of deep-water conodonts in Kazakhstan is lower and comprises no more than five–six species in total. Stratigraphic distribution of conodonts in the Burubaital Formation sections along with their distribution in the previously studied chert localities in Kazakhstan were used as a base to estimate the succession of conodont zones in deep-water siliceous deposits. The resulting conodont zonation is based on cosmopolitan conodont species and allows broad correlation with deposits of several other paleocontinents.The pelagic habitat of the Early Ordovician oceans is subdivided into two latitudinal biogeographical units - tropical, recorded in Siberia, Laurentia and adjacent terranes, and temperate to cold climate zone, recorded in Baltoscandia, Avalonia and Western Gondwana. The low gradient between the climate of high and low latitudes confirms that the climate in the Early Ordovician was warmer than in the Middle Ordovician.

Testing tropical biogeographical regions using the palm family as a model clade

AbstractAimSince Wallace's and Engler's 19th‐century biogeographical schemes, biogeographers have sought to classify the world into biogeographical regions according to patterns in biotic distribution. Yet, while most of the world's plant biodiversity can be found in the tropics, basic phytogeographical relationships and boundaries within this zone remain debated. We investigated whether palms, a species‐rich, well‐studied pantropical family, reflect traditional floristic schemes or support a recently published phylogenetic regionalisation that contests the traditional views on phytogeographical tropical regions.LocationTropics and subtropics.TaxonPalm family (Arecaceae).MethodsWe use a species‐level dated phylogenetic tree of palms along with a dataset of all palm species distributions to calculate pairwise phylogenetic beta diversity among palm assemblages. From these pairwise dissimilarity values, we compute the relationship between assemblages in NMDS ordination space and use hierarchical clustering to define biogeographical units for palms.ResultsWe found a Neotropical versus Palaeotropical division of palm assemblages as the major biogeographical split. Two Neotropical and four Palaeotropical clusters were identified with the following relationships: ((Southern Neotropical, Northern Neotropical), ((Indian Ocean), ((African), (Eurasian‐Australian, Melanesian‐Pacific)))).Main ConclusionsOur analysis supports many delineations suggested in traditional floristic schemes, most importantly a clear Neotropical versus Palaeotropical division and units resembling Takhtajan's African, Indo‐Malesian, New Caledonian and Polynesian Palaeotropical subkingdoms. However, as recently suggested in phylogenetic regionalisation, our results also show a clustering of Southeast Asian and Australian assemblages, substantiating the suggestion of a combined Asian‐Australian region. Biogeographical regionalisation for palms does not support the existence of trans‐continental dry tropical or subtropical phytogeographical clusters that have recently been found in dicot trees, despite known Northern Hemisphere connections for palms. Further modern regionalisations based on multiple datasets with complementary strengths are needed to establish a credible set of phytogeographical regions for the tropics.

Biogeographical patterns of grasses (Poaceae) indigenous to South Africa, Lesotho and Eswatini

The ecological and economical importance of African grasses in sustaining animal production prompted studies to quantify the wealth of grass genetic resources indigenous to southern Africa. Plant collection and occurrence data were extracted from two southern African datasets, BODATSA and PHYTOBAS, and analysed to establish biogeographical patterns in the grass flora indigenous to South Africa, Lesotho and Eswatini. A total of 1 648 quarter degree grid cells, representing 674 grass species, were used in an agglomerative hierarchical clustering to determine biogeographical units being referred to as grasschoria. Six distinct groups formed, mainly following existing biome vegetation units, termed the Grassland, Indian Ocean Coastal Belt, Fynbos, Savanna, Central Arid Region and Succulent Karoo grasschoria. The description focuses on associated phytochoria, floristic links, key species, climate and soil properties. The main gradient distinguishing grasschoria was a rainfall-temperature gradient. The collection, conservation and breeding of pasture grass species adapted to especially arid and semi-arid environments, could be managed more efficiently by using these results, but also calling on the need to describe and label infraspecific genetic variants, including ecotypes.