Floral scent is a key mediator in many plant–pollinator interactions. It is known to vary not only among plant species, but also within species among populations. However, there is a big gap in our knowledge of whether such variability is the result of divergent selective pressures exerted by a variable pollinator climate or alternative scenarios (e.g., genetic drift). Cypripedium calceolus is a Eurasian deceptive lady’s-slipper orchid pollinated by bees. It is found from near sea level to altitudes of 2500 m. We asked whether pollinator climate and floral scents vary in a concerted manner among different altitudes. Floral scents of four populations in the Limestone Alps were collected by dynamic headspace and analyzed by gas chromatography coupled to mass spectrometry (GC/MS). Flower visitors and pollinators (the subset of visitors with pollen loads) were collected and identified. Preliminary coupled gas chromatographic and electroantennographic measurements with floral scents and pollinators revealed biologically active components. More than 70 compounds were detected in the scent samples, mainly aliphatics, terpenoids, and aromatics. Although several compounds were found in all samples, and all samples were dominated by linalool and octyl acetate, scents differed among populations. Similarly, there were strong differences in flower visitor spectra among populations with most abundant flower visitors being bees and syrphid flies at low and high altitudes, respectively. Pollinator climate differed also among populations; however, independent of altitude, most pollinators were bees of Lasioglossum, Andrena, and Nomada. Only few syrphids acted as pollinators and this is the first record of flies as pollinators in C. calceolus. The electrophysiological tests showed that bees and syrphid flies sensed many of the compounds released by the flowers, among them linalool and octyl acetate. Overall, we found that both floral scent and visitor/pollinator climate differ among populations. We discuss whether interpopulation variation in scent is a result of pollinator-mediated selection.

Background: Physical exercise is often recommended as additional treatment for people suffering from allergic rhinitis and/or asthma, but less is known about the specific effects of recreational winter outdoor exercise on allergic airway inflammation. Methods: We performed a longitudinal, randomized controlled intervention study to investigate the effects of recreational winter exercise on allergic airway inflammation, quality of life, spirometry and cardiorespiratory fitness in adults suffering from allergic rhinitis and/or asthma. The exercise group participated in a ten-day winter sports program. The control group did not receive any intervention. Results: A significant improvement of fractional oral exhaled nitric oxide (FeNO; p = 0.008, day 10) and a significant decrease in FeNO after a single 4 h hiking tour (p < 0.001, time effect) were observed for the exercise group. The nasal eosinophilic cell count revealed a short-term reduction (p = 0.021, treatment effect) in the exercise group and for the visual analogue scale sustainable improvements in allergic symptoms (p < 0.001, day 60) were found. No adverse effects of outdoor winter exercise were observed. Conclusion: Recreational winter exercise at moderately cold temperatures reduces allergic airway inflammation measured as FeNO, nasal eosinophilic cell count and induces sustainable improvements in allergic symptoms.

(1) Background: The prevalence of allergic respiratory diseases is still rising and efforts towards holistic treatments should be made. Although speleotherapy is widely applied in Europe to treat chronic airway diseases, the existing scientific evidence is rather low. Recreational winter exercise has been shown to improve allergic airway inflammation, but little is known about the combined effects of speleotherapy and recreational winter exercise. (2) Methods: In this clinical study we investigated the effects of winter exercise and speleotherapy on adults with allergic rhinitis and/or asthma. The speleotherapy group (n = 23) participated in a ten-day combined winter exercise and speleotherapy program and the exercise group (n = 18) joined a full-day winter sports program. The effects on allergic airway inflammation, quality of life, spirometry and cardiorespiratory fitness were assessed. (3) Results: No significant effects were found for fractional exhaled nitric oxide or nasal nitric oxide. Quality of life (p < 0.001 time effect) and allergic symptoms (p < 0.001 time effect) were improved in the speleotherapy and in the exercise group. (4) Conclusions: Winter exercise alone and winter exercise in combination with speleotherapy improve quality of life and allergic symptoms in adults with allergic rhinitis and/or asthma. Further studies are required to investigate the specific effects of speleotherapy. To our knowledge, this is the first investigation examining speleotherapy in combination with winter exercise. Recreational outdoor winter exercise and speleotherapy may be recommended for highly functioning patients with good disease control.

Grafetstätter C, et al. Allergy Asthma Immunol Res. 2016 Jul;8(4):312-318. http://dx.doi.org/10.4168/aair.2016.8.4.312

Floral scent is an important trait in plant–pollinator interactions. It not only varies among plant species but also among populations within species. Such variability might be caused by various non–selective factors, or, as has been shown in some instances, might be the result of divergent selective pressures exerted by variable pollinator climates. Cypripedium calceolus is a Eurasian deceptive orchid pollinated mainly by bees, which spans wide altitudinal and latitudinal gradients in mainly quite isolated populations. In the present study, we investigated whether pollinators and floral scents vary among different latitudes. Floral scents of three C. calceolus populations in the Southern Alps were collected by dynamic headspace and analyzed by gas chromatography coupled to mass spectrometry (GC/MS). These data were completed by previously published scent data of the Northern Alps and Scandinavia. The scent characteristics were compared with information on pollinators recorded for present study or available in the literature. More than 80 scent compounds were overall recorded from plants of the three regions, mainly aliphatics, terpenoids, and aromatics. Seven compounds were found in all samples, and most samples were dominated by linalool and octyl acetate. Although scents differed among regions and populations, the main compounds were similar among regions. Andrena and Lasioglossum species were the main pollinators in all three regions, with Andrena being relatively more abundant than Lasioglossum in Scandinavia. We discuss natural selection mediated by pollinators and negative frequency–dependent selection as possible reasons for the identified variation of floral scent within and among populations and regions.

Studies of floral adaptations in response to divergent pollinators are important for understanding floral evolution and diversification of plants. A plant exposed to a variable pollinator climate is Cypripedium calceolus, a threatened lady's-slipper orchid. Insect pollinators are temporarily trapped in the pouch-like labellum and escape via one of two small posterior exit holes. In escaping, they pass the stigma and an anther, depositing and collecting pollen, respectively. Successful pollination is thought to depend on the morphological fit between pollinators and flowers, with particularly thorax and exit heights being key traits. Too small insects might neither touch the stigma nor collect pollen when exiting, and too large insects do not fit through the exit but leave the flower through the entrance hole or die inside. To discern the likelihood of floral adaptations in C. calceolus to varying pollinator assemblages, we investigated (a) whether floral, vegetative, and insect traits change in a concerted manner along an altitudinal gradient, and whether the morphological fit affects (b) the escape mode of a visiting insect and (c) its probability of exporting pollen. We found that floral and vegetative traits of C. calceolus got smaller with altitude, while insect dimensions were similar across the sites. Hymenoptera, the main visitors, were more likely to escape via the exit and to export pollen when the fit was near-exact. This shows that the morphological fit plays a critical role in the pollination of C. calceolus and that pollinators have the potential to drive size-related floral adaptations.