Growth of alpine grassland will start and stop earlier under climate warming

• Published in: Nature communications 2022-12, Vol.13 (1), p.7398-10, Article 7398
• Main Authors: Möhl, Patrick, von Büren, Raphael S., Hiltbrunner, Erika
• Format: Article
• Language: English
• Subjects: 631/158/2165/2457; 631/158/2455; 631/449/2668; 704/158/2453; Adaptation, Psychological; Climate; Climate change; Global warming; Grassland; Grasslands; Growing season; Humanities and Social Sciences; Leaves; multidisciplinary; Plant Development; Plant growth; Science; Science (multidisciplinary); Seasons; Senescence; Snowmelt; Summer
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-35194-5

Alpine plants have evolved a tight seasonal cycle of growth and senescence to cope with a short growing season. The potential growing season length (GSL) is increasing because of climate warming, possibly prolonging plant growth above- and belowground. We tested whether growth dynamics in typical alpine grassland are altered when the natural GSL (2–3 months) is experimentally advanced and thus, prolonged by 2–4 months. Additional summer months did not extend the growing period, as canopy browning started 34–41 days after the start of the season, even when GSL was more than doubled. Less than 10% of roots were produced during the added months, suggesting that root growth was as conservative as leaf growth. Few species showed a weak second greening under prolonged GSL, but not the dominant sedge. A longer growing season under future climate may therefore not extend growth in this widespread alpine community, but will foster species that follow a less strict phenology. Climate change and earlier snowmelt could potentially extend the growing season for alpine grassland plants. Here, the authors combine field and chamber controlled experiments to show that extending the summer period did not result in prolonged root and leaf growth.