Global reduction of snow cover in ski areas under climate change.

Ongoing climate change substantially alters snowfall patterns with severe but diverging consequences for global ski areas. A global assessment as well as the investigation of potential implications for mountain ecosystems is currently lacking. We quantify future trends in natural snow cover days under different climate change scenarios until 2100 in seven major global skiing regions and discuss implications for mountainous biodiversity by analysing how natural snow cover days relate to regional human population density. Within all major skiing regions, snow cover days are projected to decrease substantially under every assessed climate change scenario. Thirteen percent of all current ski areas are projected to completely lose natural annual snow cover and one fifth will experience a reduction of more than 50% by 2071-2100 relative to historic baselines. Future skiable areas will concentrate in less populated areas, towards continental regions and inner parts of the mountain ranges. As skiable areas will be located at greater distances to highly populated areas in the future, we expect an expansion of infrastructure and increasing intervening actions (i.e., artificial snowmaking, slope grooming) to prolong snow duration. Our results are concerning for both the recreational and economic value of skiing as well as for mountain biodiversity since vulnerable high-altitude species might be threatened by space reductions with ski area expansion.

Outdoor cycling activity affected by COVID-19 related epidemic-control-decisions.

AIM: The lockdown of sports infrastructure due to the COVID-19 pandemic has substantially shifted people's physical activity towards public green spaces. With Germany's lockdown as one of the more severe governmentally imposed epidemic-control-decisions, we tested to what extent the frequency of outdoor cycling activities changed from March to June 2020. METHODS: User behaviour and frequency in 15 urban and 7 rural German public green spaces was quantified using cycling data from the fitness application Strava. Changes in cycling activities were analysed with four different generalised linear models, correcting for factors like weather conditions and temporal changes in the user base of the fitness application. RESULTS: We found a clear increase in outdoor cycling sport activities in urban public green spaces in response to epidemic-control decisions (e.g. increase by 81% in April relative to the expected value (95% CI [48%, 110%])). In contrast, biking in rural areas showed no significant change with epidemic-control-decisions in place. CONCLUSION: Fitness App data, e.g. from Strava, can be used to monitor visitor behaviour and frequency. The increase in outdoor cycling activities during epidemic control decisions likely reflects a shift of sport activities from indoor and team sports to outdoor and individual sports. This highlights the importance of accessible green space for maintaining physical fitness and health. Beyond this shift, it is likely that outdoor activities may be of particularly importance for stress relief in times of crisis such as the current COVID-19 pandemic.

Abundance and distribution of large microplastics (1-5 mm) within beach sediments at the Po River Delta, northeast Italy.

Coastal areas are especially prone to plastic debris, being subjected to various land- and sea-based sources. Nevertheless, knowledge about microplastic distribution on beaches is limited, as studies focused either on high tide lines, specific items, or relied on visual identification. Beaches exhibit several accumulation zones and microplastic deposition depends on particle properties. We thus studied microplastic distribution (1-5 mm), including various types and shapes, among three driftlines at three beaches within the Po River Delta. Particles were analyzed using ATR-FTIR spectroscopy. Abundances ranged from 2.92 (± 4.86 SD) to 23.30 (± 45.43 SD) microplastics per kilogram dry weight between the beaches. The accumulation of microplastics among driftlines showed no consistent pattern, besides expanded polystyrene tending to accumulate backshore. We observed that accumulation hotspots within a single driftline can disrupt a general observed accumulation pattern. Thus, microplastic monitoring guidelines should further include protocols for the handling of accumulation hotspots within datasets.