New Research Warns of Increased Nitrous Oxide Emissions from Alpine Meadows Due to Climate Warming and Land Reclamation

As climate change continues to heat our planet, researchers are investigating the impact of warming on various ecosystems. A new study by Li and colleagues, published in Frontiers in Plant Science, highlights the combined effects of warming and land reclamation on nitrous oxide (N₂O) emissions in alpine meadows. Nitrous oxide is a potent greenhouse gas, and understanding the factors contributing to its emission is crucial for mitigating climate change.

The study was conducted on the Qinghai-Tibetan Plateau, where the researchers set up a long-term experiment to examine the separate and interactive effects of warming and reclamation on soil N₂O emissions in both natural alpine meadows and cultivated grasslands. Four treatments were applied: control, warming, reclamation, and warming under reclamation.

The results revealed that both warming and reclamation independently increased N₂O emissions during both growing and non-growing seasons. However, the combination of warming and reclamation (WR) had an even more significant impact, boosting N₂O emissions by 18.9% and 81.1% during the respective seasons. The study also found that soil moisture was negatively correlated to enzymatic activity and N₂O flux.

The increase in N₂O emissions was driven by changes in soil properties, including an increase in soil nitrification, a process that contributes to N₂O production. This was due to the promotion of specific enzymatic activities by both warming and reclamation. The researchers found that reclamation made the activity of certain enzymes more sensitive to warming, thus exacerbating the effects of climate change. In their article, Li and colleagues write:

Reclamation intensified the positive effects of warming on N₂O flux, due to their interaction on the decrease of soil moisture to increase ammonia monooxygenase and hydroxylamine oxidoreductase activities. However, warming, reclamation and their interactions on N₂O flux during non-growing season still needs further investigation. Our results suggest that future research should pay more attention to N₂O emissions from cultivated grasslands and the cultivated grassland in alpine meadow should be scientifically projected to better adapt to a warming climate.

Li et al. 2023.

READ THE ARTICLE

Li, Z., Li, Y., Hu, G., Wu, H., Liang, Y., Yan, J., He, S., Ganjurjav, H. and Gao, Q. (2023) “Reclamation intensifies the positive effects of warming on N₂O emission in an alpine meadow,” Frontiers in Plant Science, 14, p. 1162160. Available at: https://doi.org/10.3389/fpls.2023.1162160.