Disjunct Distribution Research Articles

Notes on the nest sites, reproductive activity, and a new record of the southernmost population of Glaucomys volans (Sciuridae: Rodentia)

ABSTRACT Glaucomys volans underwoodi was recently rediscovered in Honduras after 43 years since its last record; the population in the eastern region of the country is considered the southernmost within the distribution of this species. However, there is a lack of ecological information about this squirrel in their disjunct populations through Central America. We describe the nest sites used by this species in Honduras and give reproductive data for the southern populations for the first time. Also, we add the northernmost record for the species in Honduras. Restrained activities are needed to conserve the last remnants of pine forests and their mammals within the country.

Phylogenetic incongruence in an Asiatic species complex of the genus Caryodaphnopsis (Lauraceae)

BackgroundCaryodaphnopsis, a group of tropical trees (ca. 20 spp.) in the family Lauraceae, has an amphi-Pacific disjunct distribution: ten species are distributed in Southeast Asia, while eight species are restricted to tropical rainforests in South America. Previously, phylogenetic analyses using two nuclear markers resolved the relationships among the five species from Latin America. However, the phylogenetic relationships between the species in Asia remain poorly known.ResultsHere, we first determined the complete mitochondrial genome (mitogenome), plastome, and the nuclear ribosomal cistron (nrDNA) sequences of C. henryi with lengths of 1,168,029 bp, 154,938 bp, and 6495 bp, respectively. We found 2233 repeats and 368 potential SSRs in the mitogenome of C. henryi and 50 homologous DNA fragments between its mitogenome and plastome. Gene synteny analysis revealed a mass of rearrangements in the mitogenomes of Magnolia biondii, Hernandia nymphaeifolia, and C. henryi and only six conserved clustered genes among them. In order to reconstruct relationships for the ten Caryodaphnopsis species in Asia, we created three datasets: one for the mitogenome (coding genes and ten intergenic regions), another for the plastome (whole genome), and the other for the nuclear ribosomal cistron. All of the 22 Caryodaphnopsis individuals were divided into four, five, and six different clades in the phylogenies based on mitogenome, plastome, and nrDNA datasets, respectively.ConclusionsThe study showed phylogenetic conflicts within and between nuclear and organellar genome data of Caryodaphnopsis species. The sympatric Caryodaphnopsis species in Hekou and Malipo SW China may be related to the incomplete lineage sorting, chloroplast capture, and/or hybridization, which mixed the species as a complex in their evolutionary history.

Morphology and molecular evidence reveal hidden diversity among snapping shrimp of the Alpheus obesomanus group (Decapoda: Alpheidae) with the description of a new species from Brazil

The snapping shrimp family Alpheidae Rafinesque, 1815 includes numerous species, most of which present controversial geographical distributions. The disjunct distribution of Alpheus simus Guérin-Méneville, 1856 in the western Atlantic, from Florida to the south of the Caribbean Sea and then from Rio Grande do Norte to Bahia in Brazil, suggests that Brazilian material may belong to an undescribed species. The examination of specimens previously identified as A. simus revealed the distinct morphology of material from Brazil, resulting in the description of a new species based on morphological and molecular evidence. The specimens were collected from fragments of fire coral at the Parque Municipal Marinho do Recife de Fora, Porto Seguro, Bahia, Brazil. Alpheus coralvivo sp. nov. belongs to the A. obesomanus group and is morphologically similar to A. simus (northwestern Atlantic) and A. saxidomus Holthuis, 1980 (eastern Pacific), differing mainly in the stylocerite and scaphocerite lengths and in the large gap between the cephalothorax and pleuron of the first pleonal segment. Molecular analysis using the mitochondrial cytochrome oxidase subunit I gene support the existence of the new species.

Phylogenetics and biogeography of the olive family (Oleaceae).

Progress in the systematic studies of the olive family (Oleaceae) during the last two decades provides the opportunity to update its backbone phylogeny and to investigate its historical biogeography. We additionally aimed to understand the factors underlying the disjunct distribution pattern between East Asia and both West Asia and Europe that is found more commonly in this family than in any other woody plant families. Using a sampling of 298 species out of ca. 750, the largest in a phylogenetic study of Oleaceae thus far, and a set of 36 plastid and nuclear markers, we reconstructed and dated a new phylogenetic tree based on maximum likelihood and Bayesian methods and checked for any reticulation events. We also assessed the relative support of four competing hypotheses [Qinghai-Tibet Plateau uplift (QTP-only hypothesis), climatic fluctuations (Climate-only hypothesis), combined effects of QTP uplift and climate (QTP-Climate hypothesis), and no effects (Null hypothesis)] in explaining these disjunct distributions. We recovered all tribes and subtribes within Oleaceae as monophyletic, but uncertainty in the position of tribe Forsythieae remains. Based on this dataset, no reticulation event was detected. Our biogeographic analyses support the QTP-Climate hypothesis as the likely main explanation for the East-West Eurasian disjunctions in Oleaceae. Our results also show an earlier origin of Oleaceae at ca. 86 Mya and the role of Tropical Asia as a main source of species dispersals. Our new family-wide and extensive phylogenetic tree highlights both the stable relationships within Oleaceae, including the polyphyly of the genus Chionanthus, and the need for further systematic studies within the family's largest and most under-sampled genera (Chionanthus and Jasminum). Increased sampling will also help to fine-tune biogeographic analyses across spatial scales and geological times.

Climate refugia along Lake Superior’s shores: disjunct arctic–alpine plants rely on cool shoreline temperatures but are restricted to highly exposed habitat under climate warming

Abstract Climate refugia can serve as a remnant habitat or stepping stones for species dispersal under climate warming. The largest freshwater lake by surface area, Lake Superior, USA and Canada, serves as a model system for understanding cooling-mediated local refugia, as its cool water temperatures and wave action have maintained shoreline habitats suitable for southern disjunct populations of arctic–alpine plants since deglaciation. Here, we seek to explain spatial patterns and environmental drivers of arctic–alpine plant refugia along Lake Superior’s shores, and assess future risk to refugia under moderate (+3.5 °C) and warmest (+5.7 °C) climate warming scenarios. First, we examined how the interactive effects of summer surface water temperatures and wind affected onshore temperatures, resulting in areas of cooler refugia. Second, we developed an ecological niche model for the presence of disjunct arctic–alpine refugia (pooling 1253 occurrences from 58 species) along the lake’s shoreline. Third, we fit species distribution models for 20 of the most common arctic–alpine disjunct species and predicted presence to identify refugia hotspots. Finally, we used the two climate warming scenarios to predict changes in the presence of refugia and disjunct hotspots. Bedrock type, elevation above water, inland distance, July land surface temperature from MODIS/Terra satellite and near-shore depth of water were the best predictors of disjunct occurrences. Overall, we predicted 2236 km of the shoreline (51%) as disjunct refugia habitat for at least one species under current conditions, but this was reduced to 20% and 7% with moderate (894 km) and warmest (313 km) climate change projections.

Embracing biodiversity: multispecies population genomics of leafless Bossiaea species shows novel taxa, population dynamics and conservation strategies

Leafless Bossiaea species are a unique group of plants endemic to Australia that present intriguing challenges in taxonomy and conservation because of their morphological simplicity and often small, disjunct populations. We employed whole genome reduced representation sequencing (DArTseq) to enhance our understanding of the population dynamics, diversity and taxonomy of leafless Bossiaea species. Our dataset comprised 52,539 single-nucleotide polymorphisms across 283 samples from 7 leafless Bossiaea species, including 6 listed threatened species. We examined population structure, phylogenetic relationships, kinship and gene flow within and among populations. On the basis of our population-genomic analyses, we propose recognition of the novel taxon Bossiaea vombata subsp. orientalis and a change in status from species (B. milesiae) to subspecies for B. fragrans subsp. milesiae. Additionally, we show extensive clonal reproduction across species and limited gene flow at distances of >1 km, shedding light on the challenges faced by these species. We advocate a coordinated approach to conservation, focusing on restoring self-sustaining populations and leveraging genetic rescue strategies. By addressing the population dynamics of multiple species simultaneously in taxonomically challenging lineages, we can make informed choices to safeguard biodiversity and evolutionary potential.

Praxelis cleggiae (Compositae: Eupatorieae: Praxeliinae), a new species from the granite inselbergs in the east of the Departamento de Santa Cruz, Bolivia

SummaryPraxelis cleggiae (Compositae: Eupatorieae: Praxeliinae) is described and illustrated from the granite inselbergs (upon which it is most common), and on road crown chippings on old roads, in the Departamento de Santa Cruz, Bolivia; it has a disjunct distribution and is also found on the Serranía San Simón, in the San Ignacio Schist belt, Departamento de Beni. Material of this species was mostly determined as P. insignis (Malme) R.M.King & H.Rob., a Brazilian species, described from the metamorphosed sandstone of what is now the Parque Nacional da Chapada dos Guimarães in Mato Grosso State. The two species have some superficial resemblance, but differ significantly in plant size, internode length (relative to leaf length), branching, leaf shape and size, phyllaries, achenes and pappus. The total number of species of Praxelis recognised in Bolivia is now seven, and 20 species in the genus worldwide.

New and Noteworthy Plants for Karnataka State

13 new and noteworthy plants for the State of Karnataka are discussed in the present paper. Of these two Albizia julibrissin Durazz. and A. mollis Boiv., are Himalayan species and show disjunct distribution; three viz. Pavonia arabica Hochst. ex Steud., Tephrosia uniflora Pers. subsp. petrosa (Blatt. & Hall.) Gill. & Ali and Salvia aegyptiaca L., are dry area plants and show discontinuous distribution; two viz. Schouwia arabica (Vahl) A. P. DC. and Crotularia vestita Baker are recorded for the first time from Peninsular India; and the remaining six plants are new recrods for Karnataka State.

Historical climate change and vicariance events contributed to the intercontinental disjunct distribution pattern of ash species (Fraxinus, Oleaceae)

The Northern Hemisphere temperate forests exhibit a disjunct distributional pattern in Europe, North America, and East Asia. Here, to reveal the promoter of intercontinental disjunct distribution, Fraxinus was used as a model organism to integrate abundant fossil evidence with high-resolution phylogenies in a phytogeographic analysis. We constructed a robust phylogenetic tree using genomic data, reconstructed the geographic ancestral areas, and evaluated the effect of incorporating fossil information on the reconstructed biogeographic history. The phylogenetic relationships of Fraxinus were highly resolved and divided into seven clades. Fraxinus originated in western North America during Eocene, and six intercontinental dispersal events and five intercontinental vicariance events were occured. Results suggest that climate change and vicariance contributed to the intercontinental disjunct distribution pattern of Fraxinus. Moreover, results highlight the necessity of integrating phylogenetic relationship and fossil to improve the reliability of inferred biogeographic events and our understanding of the processes underlying disjunct distributions.

Nomenclatural Notes in <i>Munronia</i> Wt. - A Meliaceae Genus

Munronia pinnata (Wall.) A. S. Rao, comb. nov. is the plant until now known under Munronia wallichii Wt. The nomenclatural history is briefly stated. The disjunct distribution of the species is commented upon. A photograph of a herbarium specimen is also included.

Biogeographic isolation and climate shape the evolutionary heritage of Neotropical inselbergs

AbstractAimQuaternary climatic shifts can explain the current distribution of ancient ecosystems as well as the current distributions of gradients that hold species richness and diversity of several lineages in old, climatically buffered, infertile landscapes (OCBILs) as inselbergs. Thus, the combination of phylogenetic approaches and temporal landscape connectivity allows disentangling the mechanisms involved in the origin of the disjunct distribution of plant species and the evolutionary heritage of Neotropical inselbergs.LocationBrazilian Atlantic Forest and Caatinga.Time PeriodPliocene until the current period.Major TaxaAngiosperms.MethodsWe used a compiled data set of 42 inselbergs across the Atlantic Forest and Caatinga biomes in eastern Brazil to describe their structure and phylogenetic diversity and map the landscape resistance distances and the effects of resistance on their phylogenetic beta diversity. We also aimed to identify the effectiveness of protected areas and gaps in the conservation of plant species in Brazilian inselbergs.ResultsWe found evidence of dispersal limitation in the inselberg species pool and a latitudinal gradient in plant species richness and phylogenetic diversity across the Neotropical inselberg landscape, with greater isolation between the northeastern and southeastern core areas. Our findings indicate that inselbergs can lead to a high turnover of phylogenetic diversity, thus imposing distinctiveness on the evolutionary lineages of the inselberg flora.Main ConclusionsOur results suggest that the current distribution of inselberg's flora in isolated ecosystems may result from a more connected distribution of this flora in the past, as postulated by the Pleistocene habitat fluctuations. However, the patterns of diversity have probably been influenced by events much older than Quaternary climate shifts, due to inselbergs climate stability areas (refugia) since ancient periods. Conservation of mountain vegetation is a crucial strategy for maintaining biodiversity and distinct phylogenetic lineages in the current rapid global climate and land use change scenario.

Short-term extinction predicted by population viability analysis for a Neotropical salt marsh endemic bird.

Salt marshes pose challenges for the birds that inhabit them, including high rates of nest flooding, tipping, and predation. The impacts of rising sea levels and invasive species further exacerbate these challenges. To assess the urgency of conservation and adequacy of new actions, researchers and wildlife managers may use population viability analyses (PVAs) to identify population trends and major threats. We conducted PVA for Formicivora acutirostris, which is a threatened neotropical bird species endemic to salt marshes. We studied the species' demography in different sectors of an estuary in southern Brazil from 2006 to 2023 and estimated the sex ratio, longevity, productivity, first-year survival, and mortality rates. For a 133-year period, starting in 1990, we modeled four scenarios: (1) pessimistic and (2) optimistic scenarios, including the worst and best values for the parameters; (3) a baseline scenario, with intermediate values; and (4) scenarios under conservation management, with increased recruitment and/or habitat preservation. Projections indicated population decline for all assessment scenarios, with a 100% probability of extinction by 2054 in the pessimistic scenario and no extinction in the optimistic scenario. The conservation scenarios indicated population stability with 16% improvement in productivity, 10% improvement in first-year survival, and stable carrying capacity. The disjunct distribution of the species, with remnants concentrated in a broad interface with arboreal habitats, may seal the population decline by increasing nest predation. The species should be considered conservation dependent, and we recommend assisted colonization, predator control, habitat recovery, and ex situ conservation.

A taxonomic revision of Chotoy spinetail Schoeniophylax phryganophilus

Chotoy spinetail Schoeniophylax phryganophilus is widely distributed in southern and eastern South America. What was believed to be a geographically disjunct population was described, as S. p. petersi, from eastern Brazil, in the valley of the Rio São Francisco, in northern Minas Gerais and western Bahia, based on comparatively minor plumage characters (chiefly colour and strength of the streaking). Its range was subsequently believed to extend to the northeast Brazilian state of Piauí. We analysed a total of 91 specimens of Schoeniophylax (74 S. p. phryganophilus, 17 S. p. petersi) for external morphology (plumage and biometrics), and 27 recordings of the species’ main song (22 S. p. phryganophilus and five S. p. petersi). We found no evidence to support intraspecific geographical variation, which is unsurprising in the light of vastly increased fieldwork that has removed any obvious disjunction in the distribution of Schoeniophylax, and we therefore recommend that the species be returned to monotypy.

Regulation of Green Fluorescent Proteins by Sea Anemones (Anthopleura spp.) in Response to Light.

Green Fluorescent Proteins (GFPs) are a family of proteins with a disjunct systematic distribution; their biological functions remain speculative for the most part. Here we report studies of 3 closely related species of green sea anemones (Anthopleura) that express GFPs throughout their ectoderm. Individuals of these species maintain facultative symbiosis with zooxanthellae in their endoderm and inhabit the rocky intertidal or shallow subtidal. Thus, they depend on exposure to light to maintain photosynthesis of their symbionts, and simultaneously need to manage stresses associated with this exposure. We present experimental evidence that these sea anemones regulate the amount of GFP in their bodies in response to the surrounding light environment: they increase or reduce GFP when exposed to brighter or dimmer light, respectively, yet they maintain some GFP while in darkness, for surprisingly long periods.

Molecular phylogenetic studies on Asparagus (Asparagaceae) revealed the position of the highly endangered Irano-Turkish halophytic species A. lycaonicus P.H.Davis related to A. officinalis L.

Asparagus lycaonicus P.H.Davis (Asparagaceae), a highly interesting halophytic species was found in two disjunct populations of ca. 1550 km aerial distance, one in Central Anatolia (Bolluk Salt Lake) and the other in Central Iran (Meyghan Salt Lake). Using one nuclear phytochrome C (PHYC) and two plastid regions (trnH-psbA and trnD-T) the phylogenetic position of this Irano-Turkish endemic species was studied. In contrast to low resolution of plastid sequences, the PHYC provides good resolution for understanding species level phylogeny in SW Asian Asparagus. Molecular data confirms a conspecific position of the two disjunct localities in Turkey and Iran and their position in a clade containing cultivated Asparagus and many other Irano-Turkish species. Asparagus lycaonicus is extremely rare in Iran and since its discovery in 1986, it has never been rediscovered in Iran, even in its initial collection site. Intensive land use activities, water level changes and the passage of Arak wastewater into the Meyghan Salt Lake area has drastically changed the habitat of A. lycaonicus and might have caused its extinction. Since its discovery in 1960 in Turkey, the species is only found in a small area around and inside a sodic extraction factory around Bolluk Lake. Considering the critical condition of its populations in Iran and Turkey, we evaluate the conservation status of Asparagus lycaonicus as Critically Endangered (CR). In conclusion we urge the authorities to implement in situ measures for conservation and restoration of the habitats of A. lycaonicus, a halophytic species related to cultivated Asparagus. The taxonomic status of some newly described Asparagus from Iran is discussed with reducing A. touranensis Hamdi & Assadi to synonym of A. griffithii Baker., A. khorasanensis Hamdi & Assadi to synonym of A. breslerianus Schult. & Schult.f, and Asparagus bojnurdensis Hamdi & Assadi to synonym of A. verticillatus L.

DNA barcoding reveals a new population of the threatened Atlantic Forest frog Sphaenorhynchus canga

Species identification plays a significant role in biodiversity conservation. As many species remain unrecognized, particularly in neotropical hotspots like the Brazilian Atlantic Forest (AF), novel molecular techniques are being widely employed to bridge this gap. In this study, we used DNA barcoding and phylogenetic tools to identify a new population of Sphaenorynchus canga in the central region of the Brazilian AF. Our results extend the species’ known distribution by approximately 200 km to the south, encompassing a different mountain range than its type locality (Serra do Espinhaço). This disjunct distribution, while not uncommon among amphibians, suggests a historical connection between these two mountain complexes as a biogeographic explanation. Despite the discovery of a new S. canga population, the species continues to face numerous anthropogenic threats such as mining, land use, and cattle ranching. Urgent conservation and research efforts are warranted to ensure the survival of S. canga populations across these habitats.

Greener leaves from northern trees: Latitudinal compensation in riparian cottonwoods

Narrowleaf cottonwoods (Populus angustifolia) occur in disjunct populations along rivers in a north-south corridor of the Rocky Mountain regions from Alberta, Canada, to Arizona, USA. This distribution should allow genetic divergence to provide localized ecophysiological adaptation. To test this, we compared 167 genotypes in ten source populations from across the full latitudinal range of 16° (1800 km). Replicated clonal saplings were grown for three years in a common garden at the northern range limit, where we found that shoot characteristics were correlated with the latitude of origin. Southern populations displayed increased height and stem diameter (populations: r2 = 0.489 and 0.472) due to extended in-leaf growing seasons. However, this produced a phenological mismatch, with increased fall frost injury and shoot die-back. With increasing latitude of origin there were foliar differences across the populations, with higher chlorophyll content (chl, r2 = 0.836), nitrogen (N, r2 = 0.429), and leaf mass per area (LMA, r2 = 0.474). Similar latitudinal correspondences were observed across the individual genotypes, again with the strongest correlation for chl (r2 = 0.188). Across the genotypes, chl was positively correlated with leaf length, width, area, and mass, and especially with foliar N (r2 = 0.354), which was also correlated with foliar δ13C (r2 = 0.230). The heritable correspondences between source latitude and foliar characteristics could enable vigorous photosynthesis during the shorter, northern growing season, providing latitudinal compensation. Conversely, slower photosynthesis would reduce the foliar aging rate, enabling leaf function through the longer, southern growing season. The alternate foliar strategies could accommodate the limited ‘leafspan’, or leaf lifespan. This adaptive variation in foliar physiology would impact natural or assisted northward migration of cottonwood populations in response to climate change. It could also be useful for poplar breeding, with northern genotypes contributing genes to increase photosynthetic capacity. Finally, groupings of the populations based on the combined ecophysiological traits were very consistent with genetically defined ecotypes, supporting the evolution of subspecies types within this obligate riparian tree.

Not All Edible Nuts Are Eaten: Evidence for Continued Aboriginal Cultural Use and Dispersal of Bunya Pine (Araucaria bidwillii) in Southern But Not in Northern Queensland

Globally, there is increasing evidence that Indigenous peoples have manipulated plant and animal populations over millennia. The Bunya Pine ( Araucaria bidwillii Hook.) is a coniferous tree native to subtropical and tropical eastern Australia, which produces 30–100 large, edible seeds within a large cone weighing 5–10 kgs. Endemic Bunya populations occur as two disjunct populations: one in south-eastern Queensland/north-east New South Wales and the other in northern Queensland. We investigated possible pre- and postcolonial Bunya seed dispersal within and between the two separate populations by utilising multidisciplinary methods to examine Aboriginal cultural connections with Bunya. Analysis of historical sources and ethnographic interviews conducted with Aboriginal knowledge holders provided strong evidence for localised deliberate dispersal within the southern population but no solid evidence for dispersal in the north, suggesting two distinct modes of Aboriginal interaction with this species. Early European colonial records documented the Indigenous cultural significance of southern Bunya, evidenced by large feast gatherings, creation Stories, Aboriginal familial tree connections, seed carrying and planting, and storage in camps. The continued cultural attachment post-colonisation was evident from ethnographic interviews with Indigenous knowledge holders that revealed plantings of this species on Aboriginal missions and modern grave sites. The development of an overarching effective biocultural management plan to conserve the biological and cultural importance of this species is therefore particularly important for the southern population, especially in the face of new threats from pathogenic dieback. The individal tree connections of certain Aboriginal families also warrant deeper ethnographic study to target planting and restoration efforts that preserve these kin-based biocultural connections.

Recurrent gene flow events occurred during the diversification of clownfishes of the skunk complex.

Clownfish (subfamily Amphiprioninae) are an iconic group of coral reef fish that evolved a mutualistic interaction with sea anemones, which triggered the adaptive radiation of the clade. Within clownfishes, the "skunk complex" is particularly interesting. Besides ecological speciation, interspecific gene flow and hybrid speciation are thought to have shaped the evolution of the group. We investigated the mechanisms characterizing the diversification of this complex. By taking advantage of their disjunct geographical distribution, we obtained whole-genome data of sympatric and allopatric populations of the three main species of the complex (Amphiprion akallopisos, A. perideraion and A. sandaracinos). We examined population structure, genomic divergence and introgression signals and performed demographic modelling to identify the most realistic diversification scenario. We excluded scenarios of strict isolation or hybrid origin of A. sandaracinos. We discovered moderate gene flow from A. perideraion to the ancestor of A. akallopisos + A. sandaracinos and weak gene flow between the species in the Indo-Australian Archipelago throughout the diversification of the group. We identified introgressed regions in A. sandaracinos and detected in A. perideraion two large regions of high divergence from the two other species. While we found that gene flow has occurred throughout the species' diversification, we also observed that recent admixture was less pervasive than initially thought, suggesting a role of host repartition or behavioural barriers in maintaining the genetic identity of the species in sympatry.

Leionema paulii (Rutaceae), a new, range-restricted endemic species from south-eastern New South Wales, Australia

Leionema paulii G.P.Phillips (Rutaceae), a newly recognised species of restricted distribution from montane south-eastern New South Wales is here described. It is compared with the morphologically similar L. phylicifolium (F.Muell.) Paul G.Wilson, L. ceratogynum N.G.Walsh and L. lachnaeoides (A.Cunn.) Paul G.Wilson. The distribution, habitat and proposed conservation status for the new taxon are presented, and a modified key to the species of Leionema found in New South Wales is also included. Leionema paulii was previously recorded as a disjunct population of L. phylicifolium that was previously not represented by any herbarium specimens. This highlights the opportunity for further taxonomic discovery through the collection and analysis of specimens from more disjunct and discrete populations in genera that contain large numbers of narrow-range endemics.