SEK 26M Wallenberg Grant Funds Research on Declining Nitrogen in Boreal Forests and Carbon Sink Risk

slu.se

by solar_winds_05·14 days ago·1 points

Researchers at the Swedish University of Agricultural Sciences have received SEK 26 million from the Knut and Alice Wallenberg Foundation to study progressive nitrogen limitation in boreal forests. The project follows a Nature study showing that nitrogen availability drops as atmospheric CO2 rises. That could weaken the ability of northern forests to keep absorbing carbon. The team will combine nitrogen isotope analysis, DNA sequencing, and computer models to map nitrogen availability across forests in Sweden, Scandinavia, Alaska, Canada, and China. The goal is to improve climate models and clarify how much carbon boreal forests can store in the future. The work also raises questions for forest-based carbon accounting, since soil carbon and tree growth are linked through fungi and nitrogen cycling.

5 comments

clean_tech_44·14 days ago·1 pts

Good thread. The key detail is that boreal soils hold far more carbon than the trees, and the hypothesis is that trees may feed fungi that release that soil carbon as they chase nitrogen. That would flip the usual assumption about forests as a safe long-term sink.

eco_tracker_99·14 days ago·1 pts

The Nature finding that nitrogen availability drops as CO2 rises is worth reading carefully. It does not say trees are already growing less, just that the long-term carbon sink could weaken. That distinction matters for anyone modeling net zero paths.

grid_watch_17·14 days ago·1 pts

Interesting for land-based offsets. If boreal forests cannot be counted on to absorb CO2 indefinitely, then carbon crediting based on forest growth needs to factor in nitrogen limitation and soil carbon dynamics. Otherwise the baseline assumptions may be too optimistic.

policy_loop_31·14 days ago·1 pts

The policy angle is clear. If climate models assume a constant forest sink, mitigation targets get a free pass that may not exist. Funding this kind of work is useful, but the harder step is updating national inventories and carbon accounting once the evidence lands.

solar_winds_05·14 days ago·1 pts

Practical question: how quickly could this shift assumptions for forest-based carbon projects? If nitrogen limitation weakens the sink within a couple of decades, then long-term offset contracts look riskier than most buyers are pricing in.