The effect of abrupt climatic warming on biogeochemical cycling and N2O emissions in a terrestrial ecosystem


Citation: Pfeiffer, Mirjam, J. van Leeuwen, W. O. van der Knap, and J. O. Kaplan. The effect of abrupt climatic warming on biogeochemical cycling and N2O emissions in a terrestrial ecosystem. 2012. Early Rapid Warning. 391: 74-83.

Abstract:  The large, rapid increase in atmospheric N2O concentrations that occurred concurrent with the abrupt warming at the end of the Last Glacial period might have been the result of a reorganization in global biogeochemical cycles. To explore the sensitivity of nitrogen cycling in terrestrial ecosystems to abrupt warming, we combined a scenario of climate and vegetation composition change based on multiproxy data for the Oldest Dryas—Bølling abrupt warming event at Gerzensee, Switzerland, with a biogeochemical model that simulates terrestrial N uptake and release, including N2O emissions. As for many central European sites, the pollen record at the Gerzensee is remarkable for the abundant presence of the symbiotic nitrogen fixer Hippophaë rhamnoides (L.) during the abrupt warming that also marks the beginning of primary succession on immature glacial soils. Here we show that without additional nitrogen fixation, climate change results in a significant increase of N2O emissions of approximately factor 3.4 (from 6.4 ±1.9 to 21.6 ±5.9mgN2O—Nm−2yr−1). Each additional 1000mgm−2yr−1 of nitrogen added to the ecosystem through N-fixation results in additional N2O emissions of 1.6mgN2O—Nm−2yr−1 for the time with maximum H. rhamnoides coverage. Our results suggest that local reactions of emissions to abrupt climate change could have been considerably faster than the overall atmospheric concentration changes observed in polar ice. Nitrogen enrichment of soils due to the presence of symbiotic N-fixers during early primary succession not only facilitates the establishment of vegetation on soils in their initial stage of development, but can also have considerable influence on biogeochemical cycles and the release of reactive nitrogen trace gases to the atmosphere.

Justification: I chose this article because I want to learn more about chemical emissions into the environment/certain ecosystems. What spiked this interest was first discovering that methane could actually form bubbles under the ice (people have been known to even pop them) and methane is being released into colder environments from permafrost thawing. I want to learn about what other chemicals are being released and what harm or good this is doing.

down voteup vote (No Ratings Yet)

Leave a Reply