scholarly journals Altitudinal Zonation of Green Algae Biodiversity in the French Alps

2021 ◽  
Vol 12 ◽  
Author(s):  
Adeline Stewart ◽  
Delphine Rioux ◽  
Fréderic Boyer ◽  
Ludovic Gielly ◽  
François Pompanon ◽  
...  

Mountain environments are marked by an altitudinal zonation of habitat types. They are home to a multitude of terrestrial green algae, who have to cope with abiotic conditions specific to high elevation, e.g., high UV irradiance, alternating desiccation, rain and snow precipitations, extreme diurnal variations in temperature and chronic scarceness of nutrients. Even though photosynthetic green algae are primary producers colonizing open areas and potential markers of climate change, their overall biodiversity in the Alps has been poorly studied so far, in particular in soil, where algae have been shown to be key components of microbial communities. Here, we investigated whether the spatial distribution of green algae followed the altitudinal zonation of the Alps, based on the assumption that algae settle in their preferred habitats under the pressure of parameters correlated with elevation. We did so by focusing on selected representative elevational gradients at distant locations in the French Alps, where soil samples were collected at different depths. Soil was considered as either a potential natural habitat or temporary reservoir of algae. We showed that algal DNA represented a relatively low proportion of the overall eukaryotic diversity as measured by a universal Eukaryote marker. We designed two novel green algae metabarcoding markers to amplify the Chlorophyta phylum and its Chlorophyceae class, respectively. Using our newly developed markers, we showed that elevation was a strong correlate of species and genus level distribution. Altitudinal zonation was thus determined for about fifty species, with proposed accessions in reference databases. In particular, Planophila laetevirens and Bracteococcus ruber related species as well as the snow alga Sanguina genus were only found in soil starting at 2,000 m above sea level. Analysis of environmental and bioclimatic factors highlighted the importance of pH and nitrogen/carbon ratios in the vertical distribution in soil. Capacity to grow heterotrophically may determine the Trebouxiophyceae over Chlorophyceae ratio. The intensity of freezing events (freezing degree days), proved also determinant in Chlorophyceae distribution. Guidelines are discussed for future, more robust and precise analyses of environmental algal DNA in mountain ecosystems and address green algae species distribution and dynamics in response to environmental changes.

2017 ◽  
Vol 41 (4) ◽  
pp. 478-495 ◽  
Author(s):  
UK Thapa ◽  
S St. George ◽  
DK Kharal ◽  
NP Gaire

The climate of Nepal has changed rapidly over the recent decades, but most instrumental records of weather and hydrology only extend back to the 1980s. Tree rings can provide a longer perspective on recent environmental changes, and since the early 2000s, a new round of field initiatives by international researchers and Nepali scientists have more than doubled the size of the country’s tree-ring network. In this paper, we present a comprehensive analysis of the current tree-ring width network for Nepal, and use this network to estimate changes in forest growth nation-wide during the last four centuries. Ring-width chronologies in Nepal have been developed from 11 tree species, and half of the records span at least 290 years. The Nepal tree-ring width network provides a robust estimate of annual forest growth over roughly the last four centuries, but prior to this point, our mean ring-width composite fluctuates wildly due to low sample replication. Over the last four centuries, two major events are prominent in the all-Nepal composite: (i) a prolonged and widespread growth suppression during the early 1800s; and (ii) heightened growth during the most recent decade. The early 19th century decline in tree growth coincides with two major Indonesian eruptions, and suggests that short-term disturbances related to climate extremes can exert a lasting influence on the vigor of Nepal’s forests. Growth increases since AD 2000 are mainly apparent in high-elevation fir, which may be a consequence of the observed trend towards warmer temperatures, particularly during winter. This synthesis effort should be useful to establish baselines for tree-ring data in Nepal and provide a broader context to evaluate the sensitivity or behavior of this proxy in the central Himalayas.


2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Jacqueline Eng ◽  
Mark Aldenderfer

Anthropological research in the high-elevation regions of northwestern Nepal offers insights into the populationhistory of the Himalayan arc through a multi- and interdisciplinary approach that includes not only archaeologicaldata and historic and ethnographic accounts but also genomic, isotopic, and bioarchaeologicaldata, as well as innovative use of thermal niche modeling for paleoclimate reconstruction. Together these linesof evidence have allowed us to address project questions about human settlement into the region, including(1) sources of population movements into high-elevation environments of the Himalayan arc and (2) bioculturaladaptations to high-mountain environments. In this paper we compare research at several communalmortuary sites, each with a rich assemblage of material culture and human burials: Mebrak (400 B.C.–A.D. 50),Kyang (400–175 B.C.), and Samdzong (A.D. 450–650), as well as intriguing insights from finds in the earlier (ca.1250–450 B.C.) sites of Lubrak, Chokhopani, and Rhirhi. Our genomic findings demonstrate population originsfrom the Tibetan plateau, despite South Asian material culture recovered in early sites. Bioarchaeological findingsof low frequencies of non-specific stress and trauma indicate successful biocultural adaptation to highaltitudeconditions of hypoxia, cold, and low resource availability, potentially through buffering from exchangenetworks and local cultural practices, alongside high-altitude selected alleles. An integrative, multidisciplinaryapproach thus offers significantly greater opportunities for developing a more nuanced understanding of thepast processes of migration, settlement, and biocultural adaptation in the region. La investigación antropológica de las alturas del noroeste de Nepal nos proporciona conocimientos de la historiade la población del arco Himalaya a través de un enfoque multidisciplinario e interdisciplinario que incluyeno solamente datos arqueológicos y relatos históricos y etnográficos, sino también datos genómicos, isotópicos,y bioarqueológicos, tanto como uso innovador del modelado del nicho térmico para la reconstrucción paleoclimática.En conjunto, estas líneas de evidencia nos han permitido abordar temas sobre el asentamiento humanade la región, como: (1) los orígenes del movimiento hacia ambientes en las alturas del arco del Himalaya;y (2) las adaptaciones bioculturales necesarias para vivir en las alturas. En este artículo comparamos las investigacionesde varios mortuorios comunales que ofrecen conjuntos abundantes de entierros humanos y artefactosrelacionados: Mebrak (400 a.C.–d.C. 50), Kyang (400–175 a.C.), and Samdzong (d.C. 450–650), así como loshallazgos intrigantes de sitios anteriores (ca. 1250–450 a.C.) de Lubrak, Chokhopani, y Rhirhi. Nuestros datosgenómicos sugieren orígenes de le población del altiplano tibetano, a pesar del material que deriva del sur de Asia que se ha recuperado de los sitios mas tempranos. Los hallazgos bioarqueológicos demuestran niveles bajosde estrés y trauma inespecífico, y sugieren éxito en adaptación biocultural, a pesar de las condiciones de hipoxia,frio, y los recursos escasos en este ambiente. Es posible que alelos seleccionados a las alturas, junto con sistemasde intercambio y las costumbres locales contribuyeron al éxito de la adaptación. Por lo tanto, un enfoque multidisciplinarioque integra todas las evidencias ofrece una comprensión mas detallada de los procesos de migración,asentamiento, y adaptación biocultural de la región.


2014 ◽  
Vol 10 (2) ◽  
pp. 1493-1526
Author(s):  
C. Spötl ◽  
H. Cheng

Abstract. Cryogenically formed carbonate particles represent a rather new class of speleothems whose origin is directly linked to the presence of perennial ice in the subsurface. Recent studies concluded that dating these deposits provides important time constraints on the presence and the thickness of permafrost e.g. during the last glacial period. More precisely, these carbonates require the coexistence of water and ice and hence record episodes of permafrost thawing. To shed more light on the origin of the coarsely crystalline variety of these cryogenic cave carbonates – CCCcoarse for short – we examined a high-elevation cave site in the western part of the Austrian Alps which is located in an area dominated by permafrost features and transformed from an ice cave into an essentially ice-free cave during the past decade. Two side chambers of the main gallery revealed cryogenic calcite deposits whose isotopic composition indicates that they formed in individual pools of water carved in ice which underwent very slow freezing under closed-system conditions, i.e. enclosed in ice. 230Th dating shows that most of these carbonates formed ca. 2600 yr BP. Based on comparisons with other palaeoclimate archives in the Alps this thawing episode did not occur during a climate optimum, nor did CCCcoarse form in this cave during e.g. the Roman or the Medieval Warm Periods. Our results suggest that the occurrence of CCCcoarse, at least in mountain regions characterized by discontinuous permafrost, may be more stochastic than previously thought. Given the inherent heterogeneity of karst aquifers and the important role of localized water infiltration in modifying the thermal structure of the subsurface we caution against attributing CCCcoarse occurrences solely to peak warming conditions, while confirming the unique significance of these deposits in providing robust age constraints on permafrost thawing episodes.


2019 ◽  
Vol 78 (2) ◽  
Author(s):  
Angela Boggero ◽  
Silvia Zaupa ◽  
Simona Musazzi ◽  
Michela Rogora ◽  
Elzbieta Dumnicka ◽  
...  

Information on the biodiversity of high altitude lakes in the Stelvio National Park was scarce and fragmentary, in most cases limited to a few studies on a single biological issue. To fill this gap, a multidisciplinary research program was established in 2011 to investigate macroinvertebrates, diatoms, and water chemistry in 8 high altitude lakes within the boundaries of the Park (Rhaetian Alps, Eastern Alps). The results of this study were compared with data on biological assemblages and chemical parameters of Alpine lakes in the Pennine-Lepontine Alps (Western Alps), to evaluate the role of local drivers with respect to regional ones. This comparison was possible thanks to the adoption of standardized sampling methodologies developed since the ’90s by the National Research Council-Water Research Institute (Verbania), in collaboration with several European Research centers. Despite located in a restricted geographical area, the lakes of the Stelvio National Park showed a high variability of chemical composition, and of sensitivity to acidification, lower than that of the Pennine-Lepontine Alpine lakes. Macroinvertebrate and diatom taxa were ubiquitous and frequent along the Alps, and mainly represented by cold-stenothermal species. Richness, Shannon, Simpson, and Pielou indices applied to phyto- and zoobenthos highlighted significantly lower values in Stelvio National Park lakes than in those of Pennine-Lepontine for macroinvertebrates, while no significant differences were found for diatoms. Two groups of lakes were identified by Cluster Analysis, mainly on the basis of major ion concentrations. Canonical Correspondence Analysis showed that the macroinvertebrate assemblage of the lakes studied is driven mainly by altitude and lake surface, and, to a lesser extent, by nutrient content. On the contrary, pH and acid-related variables played a secondary role for diatoms, while nutrients and, more in general, ionic content had significant effects on their species composition. Overall, the results of this first investigation showed that the high elevation of these lakes affects their macroinvertebrate assemblages, while their diatom communities are comparable throughout the Alps.


2016 ◽  
Vol 43 (11) ◽  
pp. 2299-2309 ◽  
Author(s):  
Mattia Brambilla ◽  
Paolo Pedrini ◽  
Antonio Rolando ◽  
Dan E. Chamberlain

2020 ◽  
Vol 287 (1919) ◽  
pp. 20192348 ◽  
Author(s):  
Jeffrey Diez ◽  
Håvard Kauserud ◽  
Carrie Andrew ◽  
Einar Heegaard ◽  
Irmgard Krisai-Greilhuber ◽  
...  

Many plant and animal species are changing their latitudinal and/or altitudinal distributions in response to climate change, but whether fungi show similar changes is largely unknown. Here, we use historical fungal fruit body records from the European Alps to assess altitudinal changes in fungal fruiting between 1960 and 2010. We observe that many fungal species are fruiting at significantly higher elevations in 2010 compared to 1960, and especially so among soil-dwelling fungi. Wood-decay fungi, being dependent on the presence of one or a few host trees, show a slower response. Species growing at higher elevations changed their altitudinal fruiting patterns significantly more than lowland species. Environmental changes in high altitudes may lead to proportionally stronger responses, since high-altitude species live closer to their physiological limit. These aboveground changes in fruiting patterns probably mirror corresponding shifts in belowground fungal communities, suggesting parallel shifts in important ecosystem functions.


Atmosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 449
Author(s):  
Eirini Christaki ◽  
Panagiotis Dimitriou ◽  
Katerina Pantavou ◽  
Georgios K. Nikolopoulos

Water ecosystems can be rather sensitive to evolving or sudden changes in weather parameters. These changes can result in alterations in the natural habitat of pathogens, vectors, and human hosts, as well as in the transmission dynamics and geographic distribution of infectious agents. However, the interaction between climate change and infectious disease is rather complicated and not deeply understood. In this narrative review, we discuss climate-driven changes in the epidemiology of Vibrio species-associated diseases with an emphasis on cholera. Changes in environmental parameters do shape the epidemiology of Vibrio cholerae. Outbreaks of cholera cause significant disease burden, especially in developing countries. Improved sanitation systems, access to clean water, educational strategies, and vaccination campaigns can help control vibriosis. In addition, real-time assessment of climatic parameters with remote-sensing technologies in combination with robust surveillance systems could help detect environmental changes in high-risk areas and result in early public health interventions that can mitigate potential outbreaks.


2019 ◽  
Vol 13 (4) ◽  
pp. 1325-1347 ◽  
Author(s):  
Pierre Spandre ◽  
Hugues François ◽  
Deborah Verfaillie ◽  
Marc Pons ◽  
Matthieu Vernay ◽  
...  

Abstract. Climate change is increasingly regarded as a threat for winter tourism due to the combined effect of decreasing natural snow amounts and decreasing suitable periods for snowmaking. The present work investigated the snow reliability of 175 ski resorts in France (Alps and Pyrenees), Spain and Andorra under past and future conditions using state-of-the-art snowpack modelling and climate projections using Representative Concentration Pathways RCP2.6, RCP4.5 and RCP8.5. The natural snow reliability (i.e. without snowmaking) elevation showed a significant spatial variability in the reference period (1986–2005) and was shown to be highly impacted by the ongoing climate change. The reliability elevation using snowmaking is projected to rise by 200 to 300 m in the Alps and by 400 to 600 m in the Pyrenees in the near future (2030–2050) compared to the reference period for all climate scenarios. While 99 % of ski lift infrastructures exhibit adequate snow reliability in the reference period when using snowmaking, a significant fraction (14 % to 25 %) may be considered in a critical situation in the near future. Beyond the mid-century, climate projections highly depend on the scenario with either steady conditions compared to the near future (RCP2.6) or continuous decrease in snow reliability (RCP8.5). Under RCP8.5, our projections show that there would no longer be any snow-reliable ski resorts based on natural snow conditions in the French Alps and Pyrenees (France, Spain and Andorra) at the end of the century (2080–2100). For this time period and this scenario, only 24 resorts are projected to remain reliable with snowmaking, all being located in the Alps.


elni Review ◽  
2008 ◽  
pp. 39-49
Author(s):  
Birgit Dette

The Alps are experiencing a dynamic development in different areas, such as economy, social development or cross-alpine traffic and at the same time are facing environmental changes that impair the living conditions of people as well as of its flora and fauna. It is therefore important that through the Alpine Convention an international treaty has been agreed upon for the protection of the Alps with an integrative approach, embracing ecological, economic and social aspects. This article provides an overview of the objectives and content of the Alpine Convention. It also takes a look at its genesis and implementation as well as the different stakeholders that are involved therein. The article further examines the specific characteristics of the Alpine Convention such as its mechanisms for dispute resolution and its aspects of public participation. In this context a parallel is drawn to the Aarhus Convention which is likewise an NGO-driven international Convention.


Genome ◽  
1992 ◽  
Vol 35 (6) ◽  
pp. 1050-1053 ◽  
Author(s):  
Simon T. Bennett ◽  
Michael D. Bennett

Mean 2C DNA amounts varied by 35.6%, ranging from 7.52 to 10.20 pg, between 10 populations of the grass Milium effusum L. Such intraspecific variation occurred despite a constant chromosome number (2n = 28) and no obvious differences in karyotype. Plants originating from botanic garden populations growing in cultivation had significantly (P < 0.001) larger DNA amounts than plants collected from wild populations. Moreover, variation in DNA amount within either the "cultivated" or the "wild" groups was not significant. As the environment in which plants are kept in botanic gardens is clearly different to the natural habitat for M. effusum, it seems likely that the difference in nuclear DNA amount is causally related, perhaps through its nucleotypic effects, to microclimate adaptation. These results suggest that at least some genotypes of M. effusum are fluid and sensitive to environmental change. Such data may have broad practical importance regarding plant responses to various environmental changes such as a nuclear winter and global warming, and implications for plant conservation and reintroduction. Milium effusum is a potentially useful plant material for studying the nature of intraspecific variation in DNA amount.Key words: Milium effusum, nuclear DNA amounts, nucleotype, environmental adaptation.


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