Laut einer 24-jährigen Studie über Grasland in Minnesota dämpft der steigende CO2-Gehalt zunächst die Auswirkungen der Stickstoffverschmutzung auf die Pflanzenbiodiversität, verstärkt sie aber schließlich. Laut einer neuen Studie der University of Michigan verdeutlicht dies eine wachsende Bedrohung für den Schutz der biologischen Vielfalt.
Nitrogen pollution and rising carbon dioxide: A joint threat to grassland biodiversity?
1 Comment
“Dozens of studies have demonstrated that nitrogen pollution, due mainly to the burning of fossil fuels and agricultural practices, is causing plant biodiversity losses worldwide.
But whether rising levels of climate-warming carbon dioxide gas are amplifying those nitrogen-induced biodiversity losses or dampening them remains unclear and is an understudied topic.
The newly published findings of an ecologically realistic 24-year field study involving 108 experimental grassland plots in Minnesota provide an answer that doesn’t bode well for biodiversity conservation efforts—at least for grasslands.
During the most recent eight years of the study, experimentally elevated levels of carbon dioxide nearly tripled species losses attributed to the long-term application of simulated nitrogen pollution.
Specifically, plots that received added nitrogen saw species richness—the number of plant species per plot—reduced by an average of 7% at ambient carbon dioxide levels and by 19% at elevated carbon dioxide levels.
“If rising carbon dioxide generally exacerbates the widespread negative impacts of nitrogen deposition on plant diversity, as observed in our study, this bodes poorly for conservation of grassland biodiversity worldwide,” said University of Michigan ecologist and study lead author Peter Reich.
“Maintaining biodiversity is critical because diverse plant communities provide services to people, such as water purification, crop pollination benefits, maintaining healthy soils, slowing down climate change by storing carbon, and being home to diverse butterfly, bird and mammal communities.”
The findings were published Oct. 16 in the journal Nature.
…”
I’ve linked to the press release in the above post. For those interested, here’s the study: [High CO2 dampens then amplifies N-induced diversity loss over 24 years](https://www.nature.com/articles/s41586-024-08066-9) (DOI: 10.1038/s41586-024-08066-9)