Michael Zehnder, a PhD student at the Swiss Federal Institute for Forest, Snow, and Landscape Research (SLF), just put the finishing touches on this discovery. For example, he showed dramatic shifts in spring onset timing across the Alpine region. His latest research, published in Global Change Biology, looked at data collected between 1998 and 2023. It discovered that spring in the Alps now arrives an average of six days earlier than it did a quarter-century ago. This study, published today in Nature Ecology and Evolution, paints a grim picture of the effects of climate change on mountain ecosystems.
Zehnder’s research addressed the mechanisms underlying the phenological advances observed in Alpine grasslands, working to understand how these ecosystems react to changing climate patterns. In order to carry out his research, he used data gathered from 40 Intercantonal Measurement and Information System (IMIS) weather stations. These stations offered invaluable information about the local climatic conditions that dictate vegetation growth.
As part of his research project, Zehnder went to all the measuring stations at an altitude between 1,700 and 2,700 meters above sea level. That passion inspired him to document vegetation shifts by observing plants in their natural habitats. He operated these sensors remotely, using them to measure snow depth all winter long. This innovation allowed him to narrow down the timing of snowmelt, a key variable that determines when plants begin their growth.
Zehnder identified a key moment in the spring when all that mountain snow melts. This breathtaking display marks the beginning of active plant growth. His summer measurements suggested that plants were wasting no time, sprouting much earlier each year. He said something remarkably perceptive. Vegetation around the treeline at roughly 2,000 meters requires additional warm days to begin growing in years with early onset of snowmelt.
The meaning of Zehnder’s findings go beyond simple ecological observations, demonstrating that climate change is truly remaking these mountain ecosystems. He notes that alpine farming might start earlier in upcoming seasons. That amendment would be a clear and needed response to the environmental changes we see occurring around us. Zehnder certainly called out the elephant in the room. Warm-weather species can out-compete species that need to use only the length of the day to time their life cycles.