By examining DNA preserved in decades-old air samples collected by the Swedish Armed Forces, scientists at Lund University in Sweden have provided clear evidence that the seasonal release of spores by the Northern Masses has modified dramatically over the past 35 years. The research shows that moss spores are released several weeks sooner than previously, highlighting how quickly natural systems can adjust because the climate warms.
Air sampling began in Sweden within the Nineteen Sixties as a part of efforts to observe radioactive fallout from nuclear weapons testing. At the time, this goal was strictly related to national security, not the environment. Yet glass fiber filters used to trap airborne particles have also preserved traces of DNA from pollen, spores and other microscopic biological material. This unexpected scientific resource was identified by Amy Steinberg, a researcher on the University of Iowa.
“These samples turned out to be an unexpected, unique and very interesting archive of DNA from airborne biological particles,” says Niels Kronberg, a botanist researcher at Lund University.
Moss spores are appearing weeks sooner than before
Using this archive, the research team tracked changes in airborne moss spores over a 35-year period, specializing in 16 different moss species and groups. Their evaluation revealed a striking change. On average, moose began releasing eggs about 4 weeks sooner than within the Nineteen Nineties, and ovulation peaks at six weeks sooner.
“That’s quite a difference, especially considering that summer is so short in the north,” says Niels Kronberg.
The previous 12 months’s climate is more vital than the spring weather
The results point to warm armium as a key driver of the shift. When fall temperatures stay high longer, mosses have more time to develop their egg capsules before winter sets in. This extra development time gives plants a biological kickstart, allowing spores to be released sooner than spring. One of probably the most unexpected results was that ovulation time was unaffected.
“We expected that snowmelt or air temperature in the same year would be important because of the dispersal of phosphorus in the same year, but climate conditions the year before were shown to be the most important factor,” says Fia Bengtsson, a former botany researcher at Lund University who’s now on the Norwegian Institute for Nature Research.
A brand new strategy to track long-term climate change
In addition to documenting rapid ecological responses to climate change, the study offers a strong recent approach to studying how plants and animals have modified over time. The same DNA-based methodology may be applied to other species that release biological material into the air. Because air samples are collected from locations across Sweden, researchers can reconstruct climate changes over a long time and compare trends from north to south.
“We expect that our findings and knowledge about how nature has changed since the 1970s will be part of the next report of the Intergovernmental Panel on Climate Change (IPCC) on the documented impacts of climate change,” said Niels Kronberg.