Mountain Chain Research Articles

Volcanical and surficial process constraints on the formation of a lake basin in Jan Mayen, Norway

The volcanic island of Jan Mayen, located in the Norwegian – Greenland Sea, has very few lake basins out of which only one, Lake Nordlaguna, holds a permanent lake throughout the year. The island is volcanic and has been glaciated, but the lake basin is not genetically typical for volcanic crater lakes or other common types of volcanic lakes. Nor is it typical for ice-scoured glacial lakes. Instead, the lake basin originated from a series of hydromagmatic and subglacial volcanic eruptions, which over time yielded an irregularly horseshoe-shaped chain of small mountains to form flanks of a bedrock basin. Potassium–Argon and Argon–Argon dates from these rock walls facing the lake yield ages ranging from about 564 to 21 ka. Subsequent glacier overriding only had a minor influence on the basin morphology, but contributed, as did other surface processes to its sediment infill. Following deglaciation, relative sea-level change led to the formation of a beach barrier that connects between the rock walls. Tectonic uplift recorded in sections and ground penetrating radar profiles around the lake perimeter and dated using radiocarbon and tephra geochemistry, is attributed to a historical eruption in 1732 CE that took place on the opposite side of the island, some 4–5 km away. The uplift blocked the last remaining passage between the basin and the ocean, leading to the present landlocked lacustrine environment.

Fast Changes in Seismic Attenuation of the Upper Crust due to Fracturing and Fluid Migration: The 2016–2017 Central Italy Seismic Sequence

The Amatrice–Visso–Norcia seismic sequence struck Central Italy across the Apenninic normal fault system in 2016. Fluids likely triggered the sequence and reduced the stability of the fault network following the first earthquake (Amatrice, Mw 6.0), with their migration nucleating the Visso (Mw 5.9) and Norcia (Mw 6.5) mainshocks. However, both spatial extent and mechanisms of fluid migration and diffusion through the network remain unclear. High fluid content, enhanced permeability, and pervasive microcracking increase seismic attenuation, but different processes contribute to different attenuation mechanisms. Here, we measured and mapped peak delay time and coda attenuation, using them as proxies of seismic scattering and absorption before and during the sequence. We observed that the structural discontinuities and lithology control the scattering losses at all frequencies, with the highest scattering delineating carbonate formations within the Gran Sasso massif. The Monti Sibillini thrust marks the strongest contrasts in scattering, indicating a barrier for northward fracture propagation. Absorption does not show any sensitivity to the presence of these main geological structures. Before the sequence, low-frequency high-absorption anomalies distribute around the NW-SE-oriented Apennine Mountain chain. During the sequence, a high-absorption anomaly develops from SSE to NNW across the seismogenic zone but remains bounded north by the Monti Sibillini thrust. We attribute this spatial expansion to the deep migration of CO2-bearing fluids across the strike of the fault network from a deep source of trapped CO2 close to the Amatrice earthquake. Fluids expand SSE-NNW primarily during the Visso sequence and then diffuse across the fault zones during the Norcia sequence.

Biodiversity and ecology of plants and arthropods on the last preserved glacier of the Apennines mountain chain (Italy)

In the current global warming phase, relict glacial areas are one of the most threatened ecosystems in the world. They are “cold-spots” of biodiversity and of great interest both from the ecological and conservation point of view. We investigated the biological communities (plants and arthropods) hosted by one of the southernmost European glaciers: Calderone Glacier, the last preserved glacier of the Apennines mountain chain (Italy). We analyzed supraglacial debris and the nearby moraine and we found a rather diverse and peculiar biodiversity, which includes also new species. Some arthropods, such as the springtail Desoria calderonis, are particularly sensitive to the presence of ice at microtopographic level. Among plants, only Arabis alpina caucasica is able to grow on the supraglacial debris, perhaps because of factors related to the seed germination and seedling survival on this habitat type. Calderone glacier, with its particular biogeographic location, is probably currently acting as one of the last refugia for rare and endemic cryophilic species within the Mediterranean Region during the ongoing warm period.

Assessment of the Morphological Pattern of the Lebanon Cedar under Changing Climate: The Mediterranean Case

The effects of climate change on species can influence the delicate balance in ecosystems. For this reason, conservation planning needs to take account of connectivity and the related ecological processes within the framework of climate change. In this study, we focus on the change in the ecological connectivity of the Lebanon cedar (Cedrus libani A. Rich.), which is widely distributed in the Mediterranean, particularly in the Amanus and Taurus Mountains. To this end, we evaluated the changes in spatial units providing connectivity in the potential and future distributions of the species through ecological niche modelling, morphological spatial pattern analysis, and landscape metrics. The results suggest that the species is moving to the northeast. According to the future projections, we predict that the potential habitat suitability of the species will shrink significantly and that, in the case of pessimistic scenarios, the extent of the suitable habitats will decrease, particularly in the western and central Taurus Mountain chains. A comparison of potential and future cores indicates that there will be a slight increase under the RCP 4.5 2050 scenario, whereas core areas will decrease in the RCP 4.5 2070, RCP 8.5 2050, and RCP 8.5 2070 scenarios. In addition, it is predicted that bridges would increase in the RCP 4.5 2070 and RCP 8.5 2050 scenarios but decrease in other scenarios.

Soils of the coastal and lower belt of Galápagos Islands – The case of Isla Santa Fé and Isla Santa Cruz

This paper compares the development of soils in low-altitude zones of two eastern Galápagos islands having a similar composition of the volcanic rock substrate but contrasting topographical features, i.e. the small and relatively flat island of Santa Fé and the larger, mountainous, younger island of Santa Cruz. The soils of the lower, dry zone of Santa Cruz are less weathered compared to those of the higher slopes on the same island. They contain basalt-derived mineral grains, swelling 2:1 phyllosilicates, and poorly crystalline kaolinite, and they are rich in calcite features. The soils on Santa Fé, in a similar altimetric position, are less weathered, containing more weatherable basalt-derived mineral grains and a clay fraction composed of open 2:1 phyllosilicates and small amounts of mica-like components, together with likely sepiolite. Sepiolite seems to occur in part in the form of small yellowish nodules. Some soils on both islands contain significant amounts of phosphate, probably linked to populations of sea birds. Compared to the parent rock, an increase in Al, Fe, Ti and K, and a loss of Mg, Ca and Na, are observed for both islands, but this is less pronounced for Santa Fé. The observed micromorphological, mineralogical and chemical differences are explained by geomorphology and related climatological factors, since the present altitudinal setting of the soils is similar. The soils of Santa Fé receive less precipitation because the island has no central mountain chain. On both islands, the heterogeneous nature of the low-elevation soils indicates major colluvial input. Biological factors, such as nesting of seabirds and the development of phytogenic calcite, may play an important role in local soil development. Remnants of illuvial clay coatings, sometimes entrapped in calcitic features, indicate wetter conditions in the past.

Moth flies (Diptera, Psychodidae) from Portugal with descriptions of a new genus, new species and additions to the fauna of the Iberian Peninsula.

Collections of Psychodidae in Portugal revealed a number of new species and a new genus for this country and the Iberian Peninsula. New species described are: Pneumia portuguesa sp. nov., Ulomyia iberica sp. nov., Clytocerus ibericus sp. nov., Pericoma estrelica sp. nov., and Psychoda iucunda sp. nov.. Heteroberdeniella gen. nov. is proposed with Berdeniella jaramensis (Wagner) as type species and Heteroberdeniella guardarramica sp. nov. is also included. Most species and genera are members of the West Palearctic fauna, but the genus Mystropsychoda Duckhouse is mentioned for the first time out of the Afrotropical realm. Distribution patterns of several genera and species cover at least the Mediterranean area and in addition indicate biogeographic relationships to the Afrotropical realm and particularly the East African mountain chains.

Response of Drainage Pattern and Basin Evolution to Tectonic and Climatic Changes Along the Dinarides-Hellenides Orogen

The junction of the Dinaric and Hellenic mountain belts hosts a trans-orogenic normal fault system (Shkoder-Peja Normal Fault, SPNF) that has accommodated oroclinal bending, as well as focused basin formation and drainage of the Drin River catchment. Analysis of fluvial morphology of this catchment reveals higher values of river slope indices (ksn) and χ (Chi) between the normal faults of the SPNF and the Drin drainage divide. The drainage divide is predicted to be migrating away from the SPNF, except at the NE end of the SPNF system. Two basins analysed in the hangingwall of the SPNF, the Western Kosovo Basin (WKB) and Tropoja Basin (TB), contain late Pliocene-to-Holocene sedimentary rocks deposited well after the main fault activity and immediately after the Last Glacial Maximum (LGM). These layers document an early Pleistocene transition from lacustrine to fluvial conditions that reflects a sudden change from internal to external drainage of paleo-lakes. In the TB, these layers were incised to form three generations of river terraces, interpreted to reflect episodic downstream incision during re-organisation of the paleo-Drin River drainage system. 36Cl-cosmogenic-nuclide depth-profile ages of the two youngest terraces (∼12, ∼8 ka) correlate with periods of wetter climate and increased sediment transport in post-LGM time. The incision rate (∼12 mm/yr) is significantly greater than reported in central and southern Albania. Thus, glacial/interglacial climatic variability, hinterland erosion and base-level changes appear to have regulated basin filling and excavation cycles when the rivers draining the WKB and TB became part of the river network emptying into the Adriatic Sea. These dramatic morphological changes occurred long after normal faulting and clockwise rotation on the SPNF initiated in late Oligocene-Miocene time. Faulting provided a structural and erosional template upon which climate-induced erosion in Holocene time effected reorganisation of the regional drainage pattern, including the formation and partial demise of lakes and basins. The arc of the main drainage divide around the SPNF deviates from the general coincidence of this divide with the NW-SE trend of the Dinaric-Hellenic mountain chain. This arc encompasses the morphological imprint left by roll-back subduction of the Adriatic slab beneath the northwestern Hellenides.

The Andes through time: evolution and distribution of Andean floras.

The Andes are the world's most biodiverse mountain chain, encompassing a complex array of ecosystems from tropical rainforests to alpine habitats. We provide a synthesis of Andean vascular plant diversity by estimating a list of all species with publicly available records, which we integrate with a phylogenetic dataset of 14 501 Neotropical plant species in 194 clades. We find that (i) the Andean flora comprises at least 28 691 georeferenced species documented to date, (ii) Northern Andean mid-elevation cloud forests are the most species-rich Andean ecosystems, (iii) the Andes are a key source and sink of Neotropical plant diversity, and (iv) the Andes, Amazonia, and other Neotropical biomes have had a considerable amount of biotic interchange through time.

Living at the limit in the Pyrenees: Peripheral and endemic plants are rare but underrepresented in protection lists

AbstractAimMountains shelter high biological diversity and constitute both important barriers and confluence areas for species. They often contain species whose populations occur at their range limit (peripheral species), which according to the “Centre‐Periphery” hypothesis (CPH) are expected to occur in marginal environments, exhibit low abundance and consequently high vulnerability. Our study investigates this hypothesis for the flora of the Pyrenees, a biogeographical crossroads containing a large proportion of the total European plant diversity.LocationPyrenees.MethodsWe determined whether more than 2600 native plant species were endemic to the Pyrenees or found at the centre or periphery of their whole distribution range within the mountain chain. We then compared the ecological preferences, local and regional abundance, and conservation status among central, peripheral and endemic species.ResultsA quarter of the flora was found at its geographic range limit within the Pyrenees. Endemic and peripheral species were more likely to be soil specialists in alpine grasslands and rocks, and exhibited smaller regional ranges than central species, but their local abundance did not tend to differ. Peripheral species at their southern range edge were more widespread regionally than at their northern range edge. Peripheral taxa were more prevalent in the Pyrenean red list of threatened species (55%) compared to national and regional protection lists (40% and 31%, respectively).Main conclusionsPeripheral species contribute substantially to the diversity of the Pyrenean flora. They follow the predictions of the CPH given their occurrence in scarce habitats, their low regional abundance and their high vulnerability according to the Pyrenean red list, although they tend to show similar local abundances as other species and are infrequent in protection lists. Integrative and cross‐border assessments of the ecology and rarity of mountain floras provide better estimates of their vulnerability and ensure more efficient prioritization of their conservation.

TDZ induces a dual morphogenetic pathway on leaf explants of the beach huckleberry – Gaylussacia brasiliensis

Gaylussacia brasiliensis is a bush from the Ericaceae family native to South America. It is considered an underutilized fruit species, despite its importance as a food source, medicinal plant, and forage for the native fauna. In the Florianópolis island, south of Brazil, it occurs in sand deposits between the Atlantic Ocean and the mountain chains of the Atlantic Rain Forest, in a vegetation type called “Restinga”, a harsh environment where plants are exposed to stressful conditions. Constand winds, high solar radiation, saltwater sprays, and low nutrient levels are common in the Restinga environment, making G. brasiliensis an important genetic resource to face the expected effects of climate change. Despite its importance, there are no sexual or asexual protocols available for its propagation. This is the first record of a micropropagation protocol for a plant of the Gaylussacia genus. We report a reliable protocol for in vitro establishment of G. brasiliensis cultures from seeds, and an efficient micropropagation protocol using leaf explants. A dual regeneration pathway, i.e., somatic embryos and adventitious shoots, can be obtained directly from leaf explants without an intermediating callus tissue. A low concentration of TDZ can be used to achieve this goal, and a high number of plants can be obtained rapidly, allowing advances in the research of this underutilized plant species and enabling its propagation for commercial or conservation purposes.

Volcanic events coincide with plant dispersal across the Northern Andes

Biological dispersal is increasingly seen as a primary driver of speciation across the tropical Andes. Similarly, growing evidence suggests that the Northern Andes cordilleras formed as disconnected segments, at least until the late Miocene. For montane species, this discontinuity can hinder dispersal to the different mountain segments. Hence, understanding which processes involved in mountain formation are related to species capacity to disperse between mountains is crucial to understanding Andean biogeography. Volcanic eruptions are known to affect biodiversity in different ways, but their effects on species connectivity through the creation of topographic growth remains largely unknown. Species that are distributed in the different geographic units of the Andes can be informative with respect to how and when the different mountains have formed. The wax palms, genus Ceroxylon, comprise 13 strictly Andean species of which three species complexes are widely distributed in the tropical Andes, inhabiting cloud forests at elevations of 1400–3500 m. We sequenced 129 individuals of all but one described species using target sequence capture to reconstruct the phylogenetic history of Ceroxylon. We inferred chronograms using secondary calibrations and demographic modeling, which along with ancestral area reconstructions, allowed us to estimate the relative contributions of dispersal and speciation in the diversification history of Ceroxylon. Geological samples of ignimbritic rocks record a Plio-Pleistocene volcanic eruption of great magnitude that connected the three Colombian cordilleras by increasing topographic growth where a former lowland pass disconnected the northern mountain segments. The timing of this topographic change coincides with an increase in dispersal events to the Western and Central Cordilleras of Colombia from adjacent Andean cordilleras (i.e. the Andes outside of Colombia). Taken together, we determine that local topographic growth resulting from volcanic eruptions played a key role in augmenting mountain chain connectivity by uplift and valley filling, which favored dispersal throughout the Northern Andes. We can spatially and temporally link a biogeographical distribution pattern to a traceable geological event.

Tectonic uplift along the northeastern margin of the Qinghai–Tibetan Plateau: Constraints from the lithofacies sequence and deposition rate of the Qaidam Basin

The uplift processes of the Qinghai–Tibetan Plateau is of great significance for understanding the tectonic dynamics and monsoons in East Asia. In this study, the spatiotemporal characteristics of the tectonic uplift along the northeastern margin of the Qinghai–Tibetan Plateau are discussed from a basin–orogen coupling perspective on the basis of detailed analyses of stratigraphy and sedimentology of the Qaidam Basin and comparisons with those of the Xining, Lanzhou, Linxia, Guide–Xunhua, and Jiuquan basins. The asynchronous tectonosedimentary events characterized by alluvial conglomerates at the Early Jurassic–Cretaceous, ~53 Ma, ~40 Ma, ~22 Ma, ~15 Ma, and <2.5 Ma have been preserved in wells at different locations. Consistently, the deposition rates indicate three episodes of accelerated deposition at ~40 Ma, ~20 Ma, and ≤5 Ma in the Cenozoic. Therefore, we believe that the orogenic uplift along the northeastern margin of the Qinghai–Tibetan Plateau can be divided into four stages: Jurassic–Cretaceous, ~40–20 Ma, ~20–5 Ma, and <5 Ma. During the Jurassic–Cretaceous, tectonic activation and uplift occurred in the ancient Qilian orogenic belt, which formed in the Early Paleozoic. By ~40 Ma, the deformation due to the growth of the “proto-Tibetan Plateau” had propagated to the Qiman Tagh Shan–East Kunlun Shan–Ela Shan–West Qinling Mountain chain. Controlled by the tectonic thrusting of the eastern Kunlun Mountains, the Qaidam Basin entered a stage of comprehensive development. At ~20 Ma, the deformation front of the Qinghai–Tibetan Plateau reached the Qilian Shan. The unified Paleogene compressional basin in the northern West Qinling Mountains split into secondary basins, such as the Xining, Lanzhou, Linxia, Guide–Xunhua, and Gonghe basins, which evolved independently. At ~5 Ma, the entire Qinghai–Tibetan Plateau entered a rapid uplift stage, and the large lacustrine basins in and around the plateau shrank and disappeared.

Dendrometer measurements of Mediterranean-alpine dwarf shrubs and micro-environmental drivers of plant growth – Dataset from long-term alpine ecosystem research in the Sierra Nevada, Spain (LTAER-ES)

Here, we present measurement data of stem diameter variability of three common woody plants, monitored in the Mediterranean-alpine biome for six consecutive years (2015–2020). These focal species (Astragalus granatensis, Cytisus galianoi, and Genista versicolor) are abundant across the Sierra Nevada mountain chain (Southern Spain) and will potentially be affected by severe future climatic changes predicted for the region, including increased aridification in a warming environment. Understanding their fine-scale radial growth-patterns in relation to local environmental parameters might gain further insights into future vegetational shifts. We therefore used 139 high-resolution dendrometers to continuously monitor specimens along a steep elevational gradient and at varying topographical positions within the heterogeneous topography of the region. Additionally, we measured on-site environmental conditions at each studied site, including soil moisture and soil temperature within the root zone. All data were recorded at hourly resolution and are presented as daily mean values. The dataset was collected as a part of our long-term alpine ecosystem research program (LTAER), which functions as the basis for our recent projects on the use of dendrometer data to better understand the physiological mechanisms and the environmental drivers of the ongoing alpine greening.

Three-dimensional magnetotelluric imaging of the Mérida Andes, Venezuela

The 100km wide Mérida Andes extend from the Colombian/Venezuelan border to the Coastal Cordillera. The mountain chain and its associated major strike-slip fault systems in western Venezuela formed due to oblique convergence of the Caribbean with the South American Plates and the north-eastwards expulsion of the North Andean Block. Due to the limited knowledge of lithospheric structures related to the formation of the Mérida Andes research projects have been developed to illuminate this zone with deep geophysical data. In this study, we present three-dimensional inversion of broadband magnetotelluric data, collected along a 240km long profile crossing the Mérida Andes and the Maracaibo and Barinas–Apure foreland basins. The distribution of the stations limits resolution of the model to off-profile features. Combining 3D inversion of synthetic data sets derived from 3D modelling with 3D inversion of measured data, we could derive a 10 to 15km wide corridor with good lateral resolution to develop hypotheses about the origin of deep-reaching anomalies of high electrical conductivity. The Mérida Andes appear generally as electrically resistive structures, separated by anomalies associated with the most important fault systems of the region, the Boconó and Valera faults. Sensitivity tests suggest that the Valera Fault reaches to depths of up to 12km and the Boconó Fault to more than 35km depth. Both structures are connected to a sizeable conductor located east of the profile at 12–15km depth. We propose that the high conductivity associated with this off-profile conductor may be related to the detachment of the Trujillo Block. We also identified a conductive zone that correlates spatially with the location of a gravity low, possibly representing a SE tilt of the Maracaibo Triangular Block under the mountain chain to great depths (>30km). The relevance of these tectonic blocks in our models at crustal depths seems to be consistent with proposed theories that describe the geodynamics of western Venezuela as dominated by floating blocks or orogens. Our results stress the importance of the Trujillo Block for the current tectonic evolution of western Venezuela and confirm the relevance of the Boconó Fault carrying deformation to the lower crust and upper mantle. The Barinas–Apure and the Maracaibo sedimentary basins are imaged as electrically conductive with depths of 4 to 5km and 5 to 10km, respectively. The Barinas–Apure basin is imaged as a simple 1D structure, in contrast to the Maracaibo Basin, where a series of conductive and resistive bodies could be related to active deformation causing the juxtaposition of older geological formations and younger basin sediments.

Arc-parallel shears in collisional orogens: Global review and paleostress analyses from the NW Lesser Himalayan Sequence (Garhwal region, Uttarakhand, India)

Interest in hydrocarbon exploration from the Lesser Himalayan Sequence (LHS) has recently been revived amongst the petroleum geoscientists. Understanding the paleostress regime and the deformation mechanism are the two important steps to understand the structural geology of any (petroliferous) terrains. Arc-parallel shear is an integral deformation process in orogeny. The scale of such deformation features can range from micro-mm up to regional-scale. Unlike arc-orogen-perpendicular shear, different driving forces can produce arc-parallel shears. We review these mechanisms/theories from several orogens including the Himalaya, and compile 44 locations worldwide with arc-parallel shear. Due to continuous crustal shortening by the India-Eurasia collision, the squeezed rock mass at the plate interface has been building the Himalayan mountain chain. In addition, the rock mass also escapes laterally along the orogenic trend. Tectonic stress-field governs this mass flow. Field study and microstructural analysis in the northwest LHS (India) reveals arc-parallel brittle and ductile shear movement. Y- and P- brittle shear planes, and the S- and C- ductile shear planes reveal the following shears documented on the ~ NW-SE trending natural rock selections: (i) top-to-NW up, (ii) top-to-SE up, (iii) top-to-NW down, and (iv) top-to-SE down. Our paleostress analysis indicates top-to-SE down and top-to-NW down shears occurred due to stretching along ~131°–311° (Dext), whereas top-to-SE up and top-to-NW up shear fabric originated due to shortening along ~133.5°–313.5° (Dcompr). Previous authors considered that the arc-parallel extension generated ~15-5 Ma due to vertical thinning of the Himalaya. The NE-trending Delhi-Haridwar Ridge below the LHS plausibly acted as a barrier to the flowing mass, and piled up the rock mass in the form of NW-SE/arc-parallel compression. The NW-SE compression can be correlated with the D3 of Hintersberger et al. (2011) during ~ 4–7 Ma.

Uncovering the Brazilian Orthocentrinae (Hymenoptera: Ichneumonidae) fauna: high diversity at high elevation

Abstract The Orthocentrinae is one of the least-studied groups within Ichneumonidae and possibly a major component of the tropical fauna, encompassing a rich but still obscure diversity. In this first attempt to uncover these biota in Brazil, we surveyed a restricted area within mountain chains in the southeastern region immersed in the Atlantic tropical forest, using several sampling methods along an elevational gradient. Using integrative taxonomy, we found a richness eight times higher than the current number of species known in Brazil, including 13 genera, of which 10 are new to the country. The 127 molecular taxonomic units found represent an increase of at least 50% in species for the Neotropical fauna, confirming the immense gap in taxonomic knowledge of this group in the Neotropics. Analyses of elevational gradient patterns of distribution indicated an increase in species elevational ranges with increasing elevation, supporting Rapoport’s rule. A key including all 14 genera occurring in Brazil is proposed, aiming to facilitate future taxonomic reviews and encourage research on this group. Orthocentrinae is a major component of the fauna and likely to be more diverse in wet lowland tropical forests; however, taxonomic and faunistic studies in tropical areas, including dry forests and savannahs, are needed.

Taxonomic diversity of Passifloraceae sensu stricto along altitudinal gradient and on Serra dos Órgãos mountain slopes in southeastern Brazil

Abstract Altitudinal gradients, among other abiotic factors, are directly linked to species’ diversity patterns and distributions. Another important factor to be considered is the geographic position of a mountain chain, with oceanic and continental-facing slopes having distinct environmental conditions reflected in distinct phytophysiognomies. We examined the distributions of species of Passifloraceae sensu stricto along an altitudinal gradient (varying from 300 to 2,199 m.a.s.l.) in the Serra dos Órgãos National Park (PARNASO) in Rio de Janeiro state, southeastern Brazil. Field excursions were undertaken to record and collect specimens. Maps were prepared of the distribution of sampling efforts, taking into consideration altitudinal gradients and rainfall. The statistical analysis was made to define the patterns of richness and abundance within the altitudinal classes. Analyses of similarity, grouping and NMDS were made of the oceanic and continental slopes. A total of 19 species of Passifloraceae s.s. were encountered. The greatest species richness was found at intermediate elevations (1,100–1,300 m.a.s.l). The similarity index between the two exposure slopes was 28%, indicating distinct species compositions on different faces. Our data helps to define the distribution and species composition of Passifloraceae s.s. within the PARNASO, and should be useful for conservation actions there.

Revision and phylogenetics of the Neotropical sheet weaving spider genus

The Mounded Posterior Median Eyes (MPME) clade is a group of linyphiid spiders characterized by having posterior median eyes (PME) on a mound. The species diversity of this lineage, especially in the Neotropical region, is still largely unknown. In this study, we tackled one of the MPME groups, the genus Diplothyron Millidge, 1991. We have studied numerous specimens from both museums and freshly collected specimens to monograph Diplothyron. We also compiled both morphological and behavioral data from Diplothyron and representatives of higher-level lineages within Linyphiidae and several potential MPME groups to infer the phylogenetic relationships. We redescribed the type species, Diplothyron fuscus Millidge, 1991 and described the previously unknown male, and six new species: Diplothyron ballesterosi sp. nov., D. dianae sp. nov., D. monteverde sp. nov., D. nubilosus sp. nov., D. sandrae sp. nov. and D. solitarius sp. nov. We also transferred the following species from Linyphia to Diplothyron based on the study of the type material: D. chiapasia (Gertsch &amp; Davies, 1946) comb. nov., D. linguatulus (F.O. Pickard-Cambridge, 1902) comb. nov., D. nigritus (F.O. Pickard-Cambridge, 1902) comb. nov., D. simplicatus (F.O. Pickard-Cambridge, 1902) comb. nov. and D. trifalcatus (F.O. Pickard-Cambridge, 1902) comb. nov. Diplothyron species are mainly found in the cloud forests of Central and South America, with the distribution stretching from the Colombian Andes to the Mexican Sierra Madre across the Central American mountain chains. We also provide a detailed morphological comparison between Diplothyron and closely related genera in the MPME clade, focusing on the genital morphology, including identification keys to both the MPME genera and species of Diplothyron. Our cladistic analyses recovered Diplothyron as a monophyletic group placed within the MPME clade. A newly circumscribed lineage now includes the genera Diplothyron, Dubiaranea Mello-Leitão, 1943; Linyphia Latreille, 1804; Lomaita Bryant, 1948; Microlinyphia Gerhardt, 1928; Neriene Blackwall, 1833; Notiohyphantes Millidge, 1985; Novafrontina Millidge, 1991 and Pityohyphantes Simon, 1929.

An Overview of Historical Distribution Patterns of &lt;i&gt;Chalcides ocellatus&lt;/i&gt; (Forsskål, 1775) Using Ecological Niche Modelling: the Taurus Mountains as a Refugium

The Taurus Mountains that have a very rich biodiversity are one of the most important mountain chains in Anatolia. In this study, we examined distribution patterns of Chalcides ocellatus that has a restricted dispersal between the Taurus Mountains from the past to current using ecological niche modeling. The Taurus Mountains have played the role as a refugium area in which C. ocellatus could survive through a period of unfavorable conditions. Especially in the glaciation period, Amanos Mountains in the Middle Taurus as an isolating barrier appeared unsuitable habitats for the lineages of C. ocellatus. This indicated that the lineages of C. ocellatus were formed as a result of habitat fragmentation during the last glacial maximum and last interglacial, and were consequently adapted to different climatic conditions.

Chloroplast and Nuclear Genetic Diversity Explain the Limited Distribution of Endangered and Endemic Thuja sutchuenensis in China.

Narrow-ranged species face challenges from natural disasters and human activities, and to address why species distributes only in a limited region is of great significance. Here we investigated the genetic diversity, gene flow, and genetic differentiation in six wild and three cultivated populations of Thuja sutchuenensis, a species that survive only in the Daba mountain chain, using chloroplast simple sequence repeats (cpSSR) and nuclear restriction site-associated DNA sequencing (nRAD-seq). Wild T. sutchuenensis populations were from a common ancestral population at 203 ka, indicating they reached the Daba mountain chain before the start of population contraction at the Last Interglacial (LIG, ∼120–140 ka). T. sutchuenensis populations showed relatively high chloroplast but low nuclear genetic diversity. The genetic differentiation of nRAD-seq in any pairwise comparisons were low, while the cpSSR genetic differentiation values varied with pairwise comparisons of populations. High gene flow and low genetic differentiation resulted in a weak isolation-by-distance effect. The genetic diversity and differentiation of T. sutchuenensis explained its survival in the Daba mountain chain, while its narrow ecological niche from the relatively isolated and unique environment in the “refugia” limited its distribution.