Changes in Alpine Butterfly Communities during the Last 40 Years

Our work aims to assess how butterfly communities in the Italian Maritime Alps changed over the past 40 years, in parallel with altitudinal shifts occurring in plant communities. In 2019, we sampled butterflies at 7 grassland sites, between 1300–1900 m, previously investigated in 2009 and 1978, by semi-quantitative linear transects. Fine-scale temperature and precipitation data elaborated by optimal interpolation techniques were used to quantify climate changes. The changes in the vegetation cover and main habitat alterations were assessed by inspection of aerial photographs (1978–2018/1978–2006–2015). The vegetation structure showed a marked decrease of grassland habitats and an increase of woods (1978–2009). Plant physiognomy has remained stable in recent years (2009–2019) with some local exceptions due to geomorphic disturbance. We observed butterfly ‘species substitution’ indicating a general loss in the more specialised and a general gain in more tolerant elements. We did not observe any decrease in species richness, but rather a change in guild compositions, with (i) an overall increased abundance in some widespread and common lowland species and (ii) the disappearance (or strong decrease) of some alpine (high elevation) species, so that ‘resilience’ could be just delusive. Changes in butterfly community composition were consistent with predicted impacts of local warming.

Brief communication: Seismological analysis of flood dynamics and hydrologically-triggered earthquake swarms associated with storm Alex

On October 2, 2020, the Maritime Alps in southern France were struck by the devastating storm Alex that caused locally more than 600 mm of rain in less than 24 hours. The extreme rainfall and flooding destroyed regional rain and stream gauges. That hinders our understanding of the spatial and temporal dynamics of rainfall-runoff processes during the storm. Here, we show that seismological observations from permanent seismic stations constrain these processes at a catchment scale. The analysis of seismic power, peak frequency, and backazimuth provide us with the timing and velocity of the propagation of flash-flood waves associated with bedload-dominated phases of the flood on the Vésubie river. Moreover, the combined short-term average to long-term average ratio and template matching earthquake detection reveal that 114 local earthquakes between local magnitude ML = −0.5 and ML = 2 were triggered by the hydrological loading and/or the resulting in-situ underground pore pressure increase. This study shows the impact of storm Alex on the Earth’s surface and deep layer processes and paves the way to future works that can reveal further details of these processes.

Two new species of Protonemura Kempny, 1898 (Plecoptera: Nemouridae) from Southern France

Two new species of Protonemura Kempny, 1898, P. lupina sp. n., from the Castellane Prealps and the southern Mercantour region in the French Maritime Alps, and P. alexidis sp. n., from the southern flank of the Massif Central, are described, illustrated, and compared to their closest relative species P. risi (Jacobson & Bianchi, 1905) and P. spinulosa (Navás, 1921). Information on distribution and ecological preferences of these new species is provided.

Vegetation and Glacier Trends in the Area of the Maritime Alps Natural Park (Italy): MaxEnt Application to Predict Habitat Development

Climate change is significantly affecting ecosystem services and leading to strong impacts on the extent and distribution of glaciers and vegetation. In this context, species distribution models represent a suitable instrument for studying ecosystem development and response to climate warming. This study applies the maximum entropy model, MaxEnt, to evaluate trends and effects of climate change for three environmental indicators in the area of the Alpi Marittime Natural Park under the Municipality of Entracque (Italy). Specifically, this study focuses on the magnitude of the retreat of six glaciers and on the distribution of two different plant communities, Alnus viridis scrub and Fagus sylvatica forest associated with Acer pseudoplatanus and tall herbs (megaforbie), in relation to predicted increases in mean temperatures. MaxEnt software was used to model and observe changes over a thirty-year period, developing three scenarios: a present (2019), a past (1980) and a future (2050) using 24 “environmental layers”. This study showed the delicate climate balances of these six small glaciers that, in the next 30 years, are likely to undergo an important retreat (≈−33%) despite the high altitude and important snowfall that still characterize the area. At the same time, it is predicted that the two plant communities will invade those higher altitude territories that, not so long ago, were inhospitable, expanding their habitat by 50%. The MaxEnt application to glaciers has shown to be an effective tool that offers a new perspective in the climate change field as well as in biodiversity conservation planning.

Hypera temperei Hoffmann, 1958 – first discovery of the western alpine element in the Swiss Alps with biological details, and new morphological insights (Coleoptera, Curculionidae)

Since its description based on a single female from the Maritime Alps in France, no other localities of this enigmatic alpine species have become public. In a scree slope in the Valais at high montane altitude Hypera temperei Hoffmann, 1958 was discovered for the first time elsewhere, in Switzerland. The species’ biology is unravelled, its habitat is described, and photographs of the male, larvae and pupa are presented. The re-investigation of the species morphology revealed that Hypera temperei is closest to H. postica (Gyllenhal, 1813), and not to H. viciae (Gyllenhal, 1813) as previously supposed. A revision of specimens in collections revealed that H. temperei is distributed even more eastern in the alpine Arc in Grisons at high montane to high alpine altitudes. Hence the species shows a considerably wider distribution in the Alps than supposed before.

Geomorphological impact of storm Alex in the Maritime Alps, France: what can we learn from seismological observations?

<p>On 2-3 October 2020, the Maritime Alps were struck by storm Alex, a violent meteorological event that triggered heavy rainfall in southeast France, more generally referred to as a "Mediterranean Episode". The Mediterranean episode generated cumulative 24-hour rainfall rate locally exceeding yearly averages (>500 mm per 24 hours). The torrential rains triggered hazardous sediment-transporting floods of an intensity never documented in the area causing several casualties, and large infrastructure and economic damage. </p><p>Rain and stream gauges’ measurements during the episode are incomplete and highly uncertain due to threshold saturation and destruction of measuring devices, and changes in the stream bed. However, 11 regional seismological stations of the French permanent network recorded continuous ground shaking during and after the episode. Significant ground unrest was generated by the geomorphological phenomena providing additional information on their temporal and spatial dynamics.</p><p>Here, we present results of the combined efforts in environmental and crustal seismology to better understand the spatiotemporal dynamics of the sediment-transporting floods and hydrological forcing on the solid Earth during and after the episode. For that, we first analyze seismic power, peak frequency, and dominant noise directions of seismic signals generated by sediment-transporting floods to infer bedload transport dynamics. Moreover, by using template matching we detect 93 small earthquakes that were triggered during the Alex episode exactly in the area where rainfall was maximum. This exceptional seismic swarm is possibly triggered by overpressure due to the water load in karsts, or changes in pore fluid pressure. Our results illustrate that seismological observations allow for better understanding and quantifying of the geomorphological impact of extreme weather phenomena in mountainous settings and the related hydro-geomorphological hazards.</p>

The Southern French–Italian Border Before, During, and After COVID-19 Lockdowns

This essay focuses on the French–Italian border of the Maritime Alps. Grounded on previous research and on more recent data, it examines both “desirable” (cross-border workers and customers) and “undesirable” (illegalized non-European migrants) circulation before, during and after the COVID-19 French and Italian lockdown.

Phylogeny of Aconitum Subgenus Aconitum in Europe

<p>Phylogenetic relations within <em>Aconitum </em>subgen. <em>Aconitum </em>(Ranunculaceae) in Europe are still unclear. To infer the phylogeny of the nuclear (ITS) region and chloroplast intergenic spacer <em>trn</em>L^(UAG)-<em>ndh</em>F of the chloroplast DNA (cpDNA), we analyzed 64 accessions within this taxon, 58 from Europe and six from the Caucasus Mts. Nuclear ITS sequences were identical in 51 European and two Caucasian accessions, whereas the remaining sequences were unique. cpDNA sequences could be categorized into five haplotypes, i.e., <em>A–E</em>, including a European-Caucasian <em>Aconitum </em>haplotype <em>B</em>. Ten cpDNA sequences were unique. A 5-bp indel distinguished the diploids from the tetraploids. None of the extant European diploids were basal to the tetraploid local group. A phylogenetic tree based on combined ITS and cpDNA sequences (bayesian inference, maximum likelihood, minimal parsimony) placed <em>Aconitum</em><em> </em><em>burnatii </em>(Maritime Alps, Massif Central) and <em>A. nevadense </em>(Sierra Nevada, Pyrenees) in a sister group to all other European species. A Bayesian relaxed clock model estimated the earliest split of the Caucasian species during the Late Miocene [ca. 7 million years ago (Mya)], and the divergence of <em>A. burnatii </em>and <em>A. nevadense </em>from the European genetic stock during the Miocene/Pliocene (ca. 4.4 Mya). Diploids in Europe are likely to be descendants of the Miocene European-Caucasian flora linked with the ancient Asian (arctiotertiary) genetic stock. The origins of the tetraploids remain unclear, and it is possible that some tetraploids originated from local, now extinct diploids. Both the diploids and tetraploids underwent rapid differentiation in the Late Pliocene – Quaternary period.</p>