Juha M Alatalo1,2, Annika K Jägerbrand3,4, Junhu Dai5,6,7, Mohammad D Mollazehi8, Abdel-Salam G Abdel-Salam8, Rajiv Pandey9, Ulf Molau10. 1. Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, P.O. Box 2713, Doha, Qatar. 2. Environmental Science Center, Qatar University, P.O. Box 2713, Doha, Qatar. 3. Calluna AB, Hästholmsvägen 28, 131 30, Nacka, Sweden. 4. Department of Environmental and Biosciences, Rydberg Laboratory of Applied Science (RLAS), School of Business, Engineering and Science, Halmstad University, P.O. Box 823, SE-301 18, Halmstad, Sweden. 5. Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China. 6. University of Chinese Academy of Sciences, Beijing, China. 7. China-Pakistan Joint Research Center on Earth Sciences, CAS-HEC, Islamabad, 45320, Pakistan. 8. Department of Mathematics, Statistics, and Physics, College of Arts and Sciences, Qatar University, P.O. Box 2713, Doha, Qatar. 9. Division of Forestry Statistics, Indian Council of Forestry Research and Education, Dehradun, India. 10. Department of Plant and Environmental Sciences, University of Gothenburg, P.O. Box 461, SE-405 30, Gothenburg, Sweden.
Abstract
PREMISE: Climate change is having major impacts on alpine and arctic regions, and inter-annual variations in temperature are likely to increase. How increased climate variability will impact plant reproduction is unclear. METHODS: In a 4-year study on fruit production by an alpine plant community in northern Sweden, we applied three warming regimes: (1) a static level of warming with open-top chambers (OTC), (2) press warming, a yearly stepwise increase in warming, and (3) pulse warming, a single-year pulse event of higher warming. We analyzed the relationship between fruit production and monthly temperatures during the budding period, fruiting period, and whole fruit production period and the effect of winter and summer precipitation on fruit production. RESULTS: Year and treatment had a significant effect on total fruit production by evergreen shrubs, Cassiope tetragona, and Dryas octopetala, with large variations between treatments and years. Year, but not treatment, had a significant effect on deciduous shrubs and graminoids, both of which increased fruit production over the 4 years, while forbs were negatively affected by the press warming, but not by year. Fruit production was influenced by ambient temperature during the previous-year budding period, current-year fruiting period, and whole fruit production period. Minimum and average temperatures were more important than maximum temperature. In general, fruit production was negatively correlated with increased precipitation. CONCLUSIONS: These results indicate that predicted increased climate variability and increased precipitation due to climate change may affect plant reproductive output and long-term community dynamics in alpine meadow communities.
PREMISE: Climate change is having major impacts on alpine and arctic regions, and inter-annual variations in temperature are likely to increase. How increased climate variability will impact plant reproduction is unclear. METHODS: In a 4-year study on fruit production by an alpine plant community in northern Sweden, we applied three warming regimes: (1) a static level of warming with open-top chambers (OTC), (2) press warming, a yearly stepwise increase in warming, and (3) pulse warming, a single-year pulse event of higher warming. We analyzed the relationship between fruit production and monthly temperatures during the budding period, fruiting period, and whole fruit production period and the effect of winter and summer precipitation on fruit production. RESULTS: Year and treatment had a significant effect on total fruit production by evergreen shrubs, Cassiope tetragona, and Dryas octopetala, with large variations between treatments and years. Year, but not treatment, had a significant effect on deciduous shrubs and graminoids, both of which increased fruit production over the 4 years, while forbs were negatively affected by the press warming, but not by year. Fruit production was influenced by ambient temperature during the previous-year budding period, current-year fruiting period, and whole fruit production period. Minimum and average temperatures were more important than maximum temperature. In general, fruit production was negatively correlated with increased precipitation. CONCLUSIONS: These results indicate that predicted increased climate variability and increased precipitation due to climate change may affect plant reproductive output and long-term community dynamics in alpine meadow communities.