Mountain Populations Research Articles

Revealing the Genetic Structure and Differentiation in Endangered Pinus bungeana by Genome-Wide SNP Markers

Understanding the genetic variation and differentiation of natural populations is essential for their protection, specifically if the species status is endangered as with Pinus bungeana. Here, we used 346,840 high density and strong specificity SNP loci to carry out genetic analyses (i.e., genetic diversity, genetic structure, phylogeny, and geographical differentiation) on 52 P. bungeana individuals from 5 populations (4 natural and one artificial) representing the main regions of the species distribution in China. Genetic diversity assessment indicated a trend of genetic diversity gradual decrease from west to east across the species distribution areas. Population genetic structure, PCA and phylogenetic analyses consistently indicated that populations in the central and eastern regions were clustered together, while those from the western regions were separated. Mantel test values indicated the presence of geographic isolation among populations, an important factor contributing to the observed genetic differentiation. The maximum likelihood tree and potential migration events inferred from TreeMix analysis indicated the presence of historical genetic exchanges between the west of Qinling Mountains and the Lvliang Mountains populations. Based on the generated genetic information, in situ and ex situ conservation strategies for P.bungeana germplasm resources are proposed, these strategies could be valuable for the conservation, protection and genetic improvement of this endangered species.

Origin, Persistence, and Vulnerability to Climate Changes of Podocarpus Populations in Central African Mountains

Background and objectives—Podocarpus latifolius (synonym of P. milanjianus) is a key tree representative of Afromontane forests where it is highly threatened by climate and land-use changes. While large populations occur in East Africa, only a few isolated and usually small populations remain in western Central Africa (Cameroon to Angola). Studying the evolutionary history of such relictual populations can thus be relevant to understand their resilience under changing environments. Materials and Methods—we developed nine polymorphic nuclear microsatellites (nSSRs) to estimate genetic variability, (historical) gene flow, and demographic changes among natural populations from Central to East Africa. Results—despite the extended distribution range of P. latifolius, a strong isolation-by-distance pattern emerges at the intra-population scale, indicating low seed and pollen dispersal capacities. Central African populations display a lower genetic diversity (He = 0.34 to 0.61) and are more differentiated from each other (FST = 0.28) than are East African populations (He = 0.65 to 0.71; FST = 0.10), suggesting high genetic drift in the Central African populations. Spatial genetic structure reveals past connections between East and West Africa but also a gene flow barrier across the equator in western Central Africa. Demographic modelling anchors the history of current lineages in the Pleistocene and supports a strong demographic decline in most western populations during the last glacial period. By contrast, no signature of demographic change was detected in East African populations. Conclusions—in Cameroon, our results exclude a recent (re)colonization from one source population of all mountain ranges, but rather indicate long-term persistence of populations in each mountain with fluctuating sizes. A higher impact of genetic drift and further loss of diversity can be expected by survival through climatically unfavorable periods in such small refugial populations. Tracking the Quaternary legacy of podocarp populations is thus essential for their conservation since there is a temporal gap between environment crises and an ecological/genetic answer at the population level.

Drivers of change in mountain and upland bird populations in Europe

Mountain ecosystems have special significance for biodiversity and are vulnerable to climate and other environmental changes. However, few assessments of drivers of change have been conducted in these areas in comparison to other more accessible biomes. In this study, we developed an objective and broad definition of a mountain bird, and systematically reviewed the existing literature for the 34 European mountain and upland species identified in order to quantify which drivers of environmental change have been most consistently associated with positive or negative demographic responses. Raptors and gamebirds were the most‐studied species, whereas mountain specialists and arctic–alpine species were little studied. Using a standardized threat classification, the analyses reported significant negative impacts of hunting, collision with energy‐generation infrastructures, predation by competitive species, human disturbance and poisoning. There were significant positive effects for management of non‐target species, but less support for effects of drivers operating over longer timescales, such as climate and land‐use changes. Analysis of trends in drivers found evidence of increasing temperatures and vegetation encroachment, whereas agricultural impacts decreased, which was largely related to abandonment of grazing. A lack of fine‐grained studies investigating ecological mechanisms and population responses to widespread impacts were highlighted. We have found that some drivers are well studied, but we need to collect more detailed and longer‐term data on species requirements and on the impacts that bird populations face to devise priorities for conservation action and research for mountain and upland birds.

Characterization of Terpene synthase variation in flowers of wild aquilegia species from Northeastern Asia.

There are several causes for the great diversity in floral terpenes. The terpene products are determined by the catalytic fidelity, efficiency and plasticity of the active sites of terpene synthases (TPSs). However, the molecular mechanism of TPS in catalyzing terpene biosynthesis and its evolutionary fate in wild plant species remain largely unknown. In this study, the functionality of terpene synthases and their natural variants were assessed in two Northeastern Asia endemic columbine species and their natural hybrid. Synoptically, TPS7, TPS8, and TPS9 were highly expressed in these Aquilegia species from the Zuojia population. The in vitro and in vivo enzymatic assays revealed that TPS7 and TPS8 mainly produced (+)-limonene and β-sesquiphellandrene, respectively, whereas TPS9 produced pinene, similar to the major components released from Aquilegia flowers. Multiple sequence alignment of Aquilegia TPS7 and TPS8 in the Zuojia population revealed amino acid polymorphisms. Domain swapping and amino acid substitution assays demonstrated that 413A, 503I and 529D had impacts on TPS7 catalytic activity, whereas 420G, 538F and 545L affected the ratio of β-sesquiphellandrene to β-bisabolene in TPS8. Moreover, these key polymorphic amino acid residues were found in Aquilegia species from the Changbai Mountain population. Interestingly, amino acid polymorphisms in TPSs were present in individuals with low expression levels, and nonsynonymous mutations could impact the catalytic activity or product specificity of these genes. The results of this study will shed new light on the function and evolution of TPS genes in wild plant species and are beneficial to the modification of plant fragrances.

Let Us Now Praise Mountain Lions: Revisiting Edward Abbey in the Santa Monica Mountains

More than 50 years have passed since Edward Abbey published Desert Solitaire—his persuasive tribute to the preservation of wilderness and wildlife, and over 30 years since he penned. In Praise of Mountain Lions: Original Praises (1984), Abbey predicted how hyper-urbanization and anthropogenic stressors would lead to habitat fragmentation and to an extinction vortex among mountain lion populations. In this essay, I engage in an interdisciplinary approach employing Edward Abbey’s esthetic theory, political ideologies, and polemic land ethic to examine the urgent plight of mountain lions struggling to survive today in the Santa Monica Mountains. It is my hope that the synthesis of Edward Abbey’s political admonitions will contribute to the emerging body of interdisciplinary environmental literary criticism and research to advocate for the protection of mountain lions in urbanized landscapes.

Linking woodland caribou abundance to forestry disturbance in southern British Columbia, Canada

AbstractThe decline of many woodland caribou (Rangifer tarandus caribou) populations is thought to be linked with habitat disturbances resulting from industrial development, including timber harvesting and its network of haul roads. Defining a disturbance‐abundance relationship offers a tool to assess and potentially manage for the influence of disturbance on caribou abundance. Defining this relationship is challenged by limited historical land use and abundance data, the choice of a disturbance measure, and variability in the relationship between subpopulations and across core versus matrix habitat. For 12 subpopulations of woodland caribou within the southern mountain population, we linked longitudinal caribou abundance data with historical forestry disturbances simulated from forest harvest data. We compared disturbance measures estimating the proportion of forested area commercially harvested with even‐aged, regeneration treatments (cutblocks) and converted to roads for transporting timber within subpopulation‐specific core and matrix habitats as predictors of caribou abundance. Non‐linear mixed models provided evidence that disturbances in matrix habitats negatively influenced caribou abundance, with the effects in core habitat being variable between subpopulations. Of the disturbance types evaluated, the best predictors included roads buffered by 50 m (R50), cutblocks ≤80 years old, and the cumulation of cutblocks ≤80 years old plus roads buffered by 50 m. The top‐ranked model was composed of R50 present in core and in matrix habitats. This model predicted a 42% (95% CI = 33–51%) reduction in caribou abundance for every 1% increase in matrix R50 (holding core R50 constant). Given the lack of pre‐forestry abundance data, we failed to directly derive critical disturbance thresholds; however, our models could be used to estimate subpopulation‐specific habitat‐disturbance thresholds necessary to achieve abundance targets. We recommend that in addition to existing protections of core habitat, few if any new roads should be built in core habitat, and that timber harvest in matrix habitat should be designed to minimize the establishment of associated roads.

A new species of Sabuloglossum (Geoglossaceae, Ascomycota) from montane areas

The fungal genus Sabuloglossum (earth tongues) was originally described as a monotypic genus based on the species Geoglossum (Microglossum) arenarium. It typically occupies sandy coastal habitats and forms mycorrhizas with Empetrum nigrum (Ericaceae). While studying material from central Europe (Czech Republic, Slovakia, Austria, and Germany), ascomata morphologically very similar to S. arenarium were observed. They were ecologically limited to mid-altitudinal mountainous habitats and associated with Calluna vulgaris or Vaccinium sp. pl. (Ericaceae). The relationship to S. arenarium and related genera was evaluated using a combination of genetic (nrITS1–5.8S–ITS2 and the 28S nrLSU regions) and comparative morphological analysis. Macro- and micromorphological investigations revealed that mountain populations differ from typical S. arenarium in longer apical cells of paraphyses, more frequently septate ascospores, and the presence of inflated cells in the stipe squamules. In phylogenetic analyses, mountain populations appeared in sister position to S. arenarium in a strongly supported clade. According to these morphological and genetic analyses, in addition to ecological and host-type specificities, the mountain populations from central Europe are proposed here as a distinct species, S. monticola sp. nov. Our study indicates that the speciation of S. monticola may have been driven predominantly by a shift in ecology and mycorrhizal association.

РЕПОПУЛЯЦИЯ ГОРНЫХ ПОСЕЛЕНИЙ: ПРОБЛЕМЫ И ПЕРСПЕКТИВЫ (На примере РСО-Алания)

Introduction. For North Ossetia, where about half of the territory is occupied by mountains, the problems of the mountain population and settlement are of particular relevance. They are becoming even more relevant now, in connection with the intensification of economic activity in the mountains, the construction of a cascade of Zaramag HPPs, the implementation of the Mamison project, the optimization of recreational activities, the development of environmentally friendly cattle breeding, fish farming, crop production, etc. Settlement began to rebuild to meet the needs of the economy, the infrastructure began to improve (gasification, electrification, computerization, etc.), the population again reached for the mountains. Research methods. The study of mountain settlement in the North Caucasus has begun relatively recently. The first works appeared in the 1990s. They covered the territory from Dagestan to Adygea. Mountain settlement in Dagestan was studied by Sh.S. Muduev [4], in Kabardino-Balkaria by A.E. Zelenskaya [5], in Adygea by F.V. Tlehuray [6]. A.D. Badov [7–9; 20]. Studies of mountain settlement were also carried out by Yu.P. Badenkov [1; 10; 11], V.S. Belozerov [12], P.P. Turun [13] and others. Research results. Currently, there is a stabilization and even a slight increase in the population in the mountainous part of North Ossetia. At the same time, in summer, the number of the living population increases significantly due to the arrival of summer residents and tourists. The number of summer residents has increased significantly over the recent period, especially in the Kurtat gorge. However, some problems of both demographic and ecological character are revealed. Thus, in a number of villages there is a significant disproportion in the sex structure of the population, which negatively affects the marriage rate of the population [5]. The dumps in the mountains have not been liquidated yet, the tailing dumps have been reclaimed with design errors and imperfections.

Genome Size, Cytotype Diversity and Reproductive Mode Variation of Cotoneaster integerrimus (Rosaceae) from the Balkans.

Cotoneaster integerrimus represents a multiploid and facultative apomictic system of widely distributed mountain populations. We used flow cytometry to determine genome size, ploidy level, and reproduction mode variation of the Balkan populations, supplemented by analysis of nuclear microsatellites in order to address: (i) geographic distribution and variation of cytotypes among the populations; (ii) variation of reproduction mode and the frequency of sexuality; (iii) pathways of endosperm formation among the sampled polyploids and their endosperm balance requirements; (iv) genotypic diversity and geographic distribution of clonal lineages of polyploids. The prevalence of apomictic tetraploid cytotype followed by sexual diploids and extremely rare triploids was demonstrated. This prevalence of tetraploids affected the populations’ structure composed from clonal genotypes with varying proportions. The co-occurrence of diploids and tetraploids generated higher cytotype, reproductive mode, and genotypic diversity, but mixed-ploidy sites were extremely rare. The endosperm imbalance facilitates the development and the occurrence of intermediate triploids in mixed-ploidy populations, but also different tetraploid lineages elsewhere with unbalanced endosperm. All these results showed that the South European populations of C. integerrimus have higher levels of cytotype and reproductive diversity compared to the Central European ones. Therefore, the South European populations can be considered as a potential reservoir of regional and global diversity for this species.

WEST NILE VIRUS IMPACTS ON BLACK-BILLED MAGPIE POPULATIONS

West Nile Virus (WNV) is an epizootic virus known to effectively kill Black-billed Magpies (Pica hudsonia). After WNV infection of humans appeared in the western United States, Black-billed Magpies birds per party-hours on Christmas Bird Counts (CBC) declined significantly. Trends for both CBC and Breeding Bird Surveys (BBS) shifted from positive before WNV infections of humans to negative during WNV infections, then rebounded to positive after WNV infection declined. Black-billed Magpies in Canada had no significant differences on CBC before or after WNV infections of humans. Canadian magpies had positive trends both before and after WNV infections on both CBC and BBS, but with negative trends during WNV infections. WNV invasion varied temporally across the continent, and Black-billed Magpies consistently showed significant and often dramatic declines soon after WNV invasion of a region. The southern Prairie region was severely hit, with Prairie states such as Kansas and Nebraska showing significant declines on CBC after WNV invasion, shifting from positive trends on CBC and BBS before invasion to negative trends during and after WNV invasion. WNV has potentially triggered or accelerated a retraction of Black-billed Magpie range in this region. The northern part of the Prairie region was less affected. Most southern and central Rocky Mountain, Intermountain, and Pacific region Black-billed Magpie populations showed significant negative effects from WNV infections. States in these regions with higher densities of Black-billed Magpies such as Colorado, Nevada, and Idaho showed significant dramatic declines during WNV invasion, but positive trends after WNV infections declined, a sign of recovering populations. California populations significantly declined with WNV invasion and have not recovered. Populations in northern and higher-elevation regions had little or no impact from WNV and populations were often stable or increasing.

Molecular Identification of Sceloporus Lizards in the Laramie Mountains, Wyoming

Accurate information on species identities and distributions is critical for informing state land use and conservation policies. However, it can often be difficult to determine species identity using morphological data alone. Using phylogenetic methods, we determined the identity of Sceloporus lizards occupying the Laramie Mountains of Wyoming, between known ranges for Sceloporus tristichus and Sceloporus consobrinus. The ND1 mitochondrial gene was sequenced for 10 individuals from the Laramie Mountains and analyzed using maximum likelihood with 23 other samples of S. tristichus and S. consobrinus from throughout their ranges. The mtDNA gene tree places the Laramie Mountains populations within a clade of Sceloporus consobrinus that includes the Rocky Mountains in Colorado. Given the prevalence of mtDNA introgression in Sceloporus, we also conducted phylogenetic analyses using 4 nuclear loci (RAG-1, R35, BDNF, and PNN) for a subset of samples. Species tree analysis of the nuclear data further verified that the Laramie Mountains population belongs to S. consobrinus. Given the very limited data available on the range, prevalence, and ecology of S. consobrinus in Wyoming, as well its designation as a Species of Greatest Conservation Need in Wyoming, more research must be done to ensure protection of this population.

Microevolutionary dynamics show tropical valleys are deeper for montane birds of the Atlantic Forest

Tropical mountains hold more biodiversity than their temperate counterparts, and this disparity is often associated with the latitudinal climatic gradient. However, distinguishing the impact of latitude versus the background effects of species history and traits is challenging due to the evolutionary distance between tropical and temperate assemblages. Here, we test whether microevolutionary processes are linked to environmental variation across a sharp latitudinal transition in 21 montane birds of the southern Atlantic Forest in Brazil. We find that effective dispersal within populations in the tropical mountains is lower and genomic differentiation is better predicted by the current environmental complexity of the region than within the subtropical populations. The concordant response of multiple co-occurring populations is consistent with spatial climatic variability as a major process driving population differentiation. Our results provide evidence for how a narrow latitudinal gradient can shape microevolutionary processes and contribute to broader scale biodiversity patterns.

THEORETICAL PREREQUISITES FOR THE STUDY OF URBOECOLOGICAL INTERACTIONS IN MOUNTAIN SETTLEMENTS OF RECREATIONAL DIRECTION

The influence of urban ecological factors on the formation of the planning structure of recreational mountain settlements in the Ukrainian Carpathians, the peculiarities of settlement in mountain conditions in terms of its compatibility with the natural environment, the importance of urban ecological interactions in terms of sustainable development of Carpathian region. It is proved that urban ecological factors of mountain settlements significantly affect the state of resource provision, architectural and spatial structure, features of recreational potential, development of tourist infrastructure, and the structure of recreational economy of the mountain region in general. 
 The purpose of the article is to find out the features of the spatial structure of mountain settlements of recreational profile under the influence of urban environmental factors and their role in solving urgent ecological, spatial and architectural problems of settlements of recreational profile on the way to sustainable development. The study of urban-ecological interactions in mountain settlements of recreational profile is quite a difficult task, given the variability of environmental factors, tense ecological situation in the region, lack of effective environmental management mechanisms, imperfect legal framework in environmental legislation, lack of strategic spatial planning and unification of environmental approaches. phenomena and processes. The urgency of the work is primarily due to the need to find effective ways to solve environmental problems in the mountain settlements of the Ukrainian Carpathians, to increase the recreational and tourist potential of the region.
 Based on the theoretical generalization of the studied literature sources, we can assume that the planning structure of mountain settlements in the Ukrainian Carpathians directly depends on the ecological situation in the region and on urban-ecological interactions between various factors of natural and man-made environment. Regarding environmental factors that have or may have an impact on the development of mountain areas, the most significant, in our opinion, are or may be: landslides, excessive devastating floods, forest fires, anthropogenic pressure, environmental pollution, biodiversity loss. Especially dangerous for not only the mountain population, but also the surrounding plains is the degradation of mountain areas in the areas of water intake. That is why, in our opinion, one of the priority and strategically important tasks is to conduct effective local and regional policy in the field of efficient and rational use of nature, aimed primarily at solving urban environmental problems in the region, which in the long run can be a key to successful mountain development.

The isolated Erebia pandrose Apennine population is genetically unique and endangered by climate change

Abstract Climate change is causing shifts in the distribution of many species and populations inhabiting mountain tops are particularly vulnerable to these threats because they are constrained in altitudinal shifts. Apennines are a relatively narrow and low mountain chain located in Southern Europe, which hosts many isolated populations of mountain species. The butterfly Erebia pandrose was recorded for the last time in the Apennines in 1977, on the top of a single massif (Monti della Laga). We confirmed the presence of a small, isolated population of E. pandrose in the Apennines, at a distance of more than 400 km to any other known populations. Then, we examined the cytochrome c oxidase subunit 1 mitochondrial DNA marker of this species across the Palaearctic area and estimated the potential decline over the Alps and the Apennines due to future climatic changes. The Apennine population represents an endemic lineage characterised by eight mutations over the 658 bp analysed (1.2%). In the Alps and Apennines, this species has shifted uphill more than 3 m per year since the end of the 19th century and more than 22 m per year since 1995. Species distribution models suggested that these mountain populations will experience a generalised loss of climatic suitability, which, according to our projections, could lead to the extinction of the Apennine population in a few decades. Erebia pandrose has the potential to become a flagship species for advertising the risk of losing unique fractions of genetic diversity for mountain species.

Altitude and latitude have different effects on population characteristics of the widespread plant Anthyllis vulneraria

Widespread plants may provide natural models for how population processes change with temperature and other environmental variables and how they may respond to global change. Similar changes in temperature can occur along altitudinal and latitudinal gradients, but hardly any study has compared the effects of the two types of gradients. We studied populations of Anthyllis vulneraria along a latitudinal gradient from Central Europe to the range limit in the North and an altitudinal gradient in the Alps from 500 m to the altitudinal limit at 2500 m, both encompassing a change in annual mean temperature of c. 11.5 °C. Plant size and reproduction decreased, but plant density increased along both gradients, indicating higher recruitment and demographic compensation among vital rates. Our results support the view that demographic compensation may be common in widespread species in contrast to the predictions of the abundant centre model of biogeography. Variation in temperature along the gradients had the strongest effects on most population characteristics, followed by that in precipitation, solar radiation, and soil nutrients. The proportion of plants flowering, seed set and seed mass declined with latitude, while the large variation in these traits along the altitudinal gradient was not related to elevation and covarying environmental variables like annual mean temperature. This suggests that it will be more difficult to draw conclusions about the potential impacts of future climate warming on plant populations in mountains, because of the importance of small-scale variation in environmental conditions.

Relative Differences in Na+/K+-ATPase Activity between Mountain and Coastal Populations of the Japanese Frog, Buergeria japonica

Buergeria japonica (Rhacophoridae) thrives in diverse habitats, from montane forests to the mouths of small rivers opening onto sandy beaches. The osmoregulatory system of B. japonica may differ between populations living in these contrasting environments. In this study, we compared the activity of cutaneous Na+/K+-ATPase in two populations of B. japonica from different habitats (montane vs. coastal). Our results reveal a significant difference between the Na+/K+-ATPase activity of the two populations of B. japonica, with the coastal population having higher Na+/K+-ATPase activity. Because the Na+/K+-ATPase plays a crucial role in osmoregulation in high salinity, these results are consistent with the higher salinity tolerance of the coastal population. It is not known whether the difference in Na+/K+-ATPase activity between populations is a result of local adaptation or phenotypic plasticity. More detailed work will be needed to disentangle the patterns of differentiation in physiological responses to salt in these amphibians.

Patterns of Leaf Morphological Traits of Beech (Fagus sylvatica L.) along an Altitudinal Gradient

Broadleaved tree species in mountainous populations usually demonstrate high levels of diversity in leaf morphology among individuals, as a response to a variety of environmental conditions associated with changes in altitude. We investigated the parameters shaping leaf morphological diversity in 80 beech individuals (Fagus sylvatica L.), in light and shade leaves, growing along an elevational gradient and under different habitat types on Mt. Paggeo in northeastern Greece. A clear altitudinal pattern was observed in the morphological leaf traits expressing lamina size and shape; with increasing altitude, trees had leaves with smaller laminas, less elongated outlines, and fewer pairs of secondary veins. However, this altitudinal trend in leaf morphology was varied in different habitat types. Furthermore, the shade leaves and light leaves showed differences in their altitudinal trend. Traits expressing lamina shape in shade leaves were more related to altitude, while leaf size appeared to be more influenced by habitat type. While the altitudinal trend in leaf morphology has been well documented for numerous broadleaved tree species, in a small spatial scale, different patterns emerged across different habitat types. This morphological variability among trees growing in a mountainous population indicates a high potential for adaptation to environmental extremes.

Recovery of silver fir (Abies alba Mill.) seedlings from ungulate browsing mirrors soil nitrogen availability.

Abies alba (Mill.) has a high potential for mitigating climate change in European mountain forests; yet, its natural regeneration is severely limited by ungulate browsing. Here, we simulated browsing in a common garden experiment to study growth and physiological traits, measured from bulk needles, using a randomized block design with two levels of browsing severity and seedlings originating from 19 populations across Switzerland. Genetic factors explained most variation in growth (on average, 51.5%) and physiological traits (10.2%) under control conditions, while heavy browsing considerably reduced the genetic effects on growth (to 30%), but doubled those on physiological traits related to carbon storage. While browsing reduced seedling height, it also lowered seedling water-use efficiency (decreased $\delta ^{13}$C) and increased their $\delta ^{15}$N. Different populations reacted differently to browsing stress, and for seedling height, starch concentration and $\delta ^{15}$N, population differences appeared to be the result of natural selection. First, we found that populations originating from the warmest regions recovered the fastest from browsing stress, and they did so by mobilizing starch from their needles, which suggests a genetic underpinning for a growth-storage trade-off across populations. Second, we found that seedlings originating from mountain populations growing on steep slopes had a higher $\delta ^{15}$N in the common garden than those originating from flat areas, indicating that they have been selected to grow on N-poor, potentially drained, soils. This finding was corroborated by the fact that nitrogen concentration in adult needles was lower on steep slopes than on flat ground, strongly indicating that steep slopes are the most N-poor environments. These results suggest that adaptation to climate and soil nitrogen availability, as well as ungulate browsing pressure, co-determine the regeneration and range limit of silver fir.

Vertical structure and microphysical observations of winter precipitation in an inner valley during the Cerdanya-2017 field campaign

Precipitation processes at windward and leeward sides of the mountains have been object of study for many decades. Instead, inner mountain valleys, where usually most mountain population lives, have received considerably less attention. This article examines precipitation processes during a winter field campaign in an inner valley of the Pyrenees (NE Spain) using, among other instruments, a K-band vertically pointing Doppler radar (Micro Rain Radar) and a laser-based optical disdrometer (Parsivel). A decoupling is found between the stalled air of the valley and the air of the free atmosphere above the mountain crest level, evidenced by an increase of turbulence and spectral width of precipitation particles. Wind shear layer may promote riming and aggregation of the ice and snow particles. Two main rainfall regimes are found during the campaign: (1) stratiform rainfall mostly produced by water vapour deposition processes, although sometimes riming and aggregation become important, and (2) weak convection with slight dominance of collision-coalescence processes. Precipitation characteristics at the bottom of the valley show typical continental features such as low Liquid Water Content, despite the valley is only about 100 km from the sea. This study demonstrates that inner valley may present distinct precipitation features with respect to windward and leeward precipitation.

Mitochondrial Differentiation and Biogeography of Rock Nuthatches

Rock Nuthatches comprise two morphologically similar species: Western Rock Nuthatch Sitta neumayer and Eastern Rock Nuthatch Sitta tephronota, with several subspecies within each species. These two species are closely related, and the two together are often considered an offshoot of the Sitta europaea group. The Western Rock Nuthatch is distributed across the Balkans to the Caucasus and Iran while the Eastern Rock Nuthatch is distributed across Eastern Anatolia, Iran, Afghanistan, Turkmenistan and Tajikistan. Using partial mitochondrial ND2 and ND3 gene sequences from populations throughout the distribution ranges and ecological niche modelling, we investigated the genetic structure and biogeographic history of these bird species. Two well-differentiated and supported clades in each species indicated a reciprocal monophyly with no gene flow between birds in the Zagros Mountains and other populations. Ecological niche modelling suggested population contraction in their potential habitat during the Last Glacial Maximum. The genetic differentiation in Zagros Mountains indicates that the post-glacial colonization of most of the Rock Nuthatch distribution range occurred from refugia located elsewhere than the Zagros Mountains. Given that Rock Nuthatches in the Zagros Mountains have long constituted an isolated population, there may be two phylogenetic species within each Rock Nuthatch species. Further genetic studies should be performed for taxonomic clarification.