Journal Article

Combined climate factors alleviate changes in gross soil nitrogen dynamics in heathlands

Björsne, Anna-Karin, Rütting, Tobias, Ambus, Per

2014

Overview

The ongoing climate change affects biogeochemical cycling in terrestrial ecosystems, but the magnitude and direction of this impact is yet unclear. To shed further light on the climate change impact, we investigated alterations in the soil nitrogen (N) cycling in a Danish heathland after 5 years of exposure to three climate change factors, i.e. warming, elevated CO₂ (eCO₂) and summer drought, applied both in isolation and in combination. By conducting laboratory ¹⁵N tracing experiments we show that warming increased both gross N mineralization and nitrification rates. In contrast, gross nitrification was decreased by eCO₂, an effect that was more pronounced when eCO₂ was combined with warming and drought. Moreover, there was an interactive effect between the warming and CO₂ treatment, especially for N mineralization: rates increased at warming alone but decreased at warming combined with eCO₂. In the full treatment combination, simulating the predicted climate for the year 2075, gross N transformations were only moderately affected compared to control, suggesting a minor alteration of the N cycle due to climate change. Overall, our study confirms the importance of multifactorial field experiments for a better understanding of N cycling in a changing climate, which is a prerequisite for more reliable model predictions of ecosystems responses to climate change.

• Publisher: Springer-Verlag,Springer,Springer International Publishing,Springer Nature B.V
• Subject: Animal and plant ecology / Animal, plant and microbial ecology / ATMOSPHERIC CARBON-DIOXIDE / Biogeochemical cycles / Biogeosciences / Biological and medical sciences / Carbon dioxide / Climate change / Climate models / Climate prediction / climatic factors / Cycles / Drought / DYNAMICS / Earth and Environmental Science / Earth and Related Environmental Sciences / Earth Sciences / Earth, ocean, space / ECOSYSTEMS / Elevated CO2 / Environmental Chemistry / Environmental factors / Environmental impact / Environmental Sciences / Exact sciences and technology / Experiments / field experimentation / Field tests / Forest soils / Fundamental and applied biological sciences. Psychology / Geosciences / Geovetenskap och relaterad miljövetenskap / Global warming / GRASSLAND SOIL / Grassland soils / Heathlands / Hypotheses / Isotope geochemistry / Isotope geochemistry. Geochronology / Life Sciences / Mineralization / Multidisciplinary / N-15 / N-15 tracing / Nitrification / Nitrogen / Nitrogen cycle / Nitrogen isotopes / Precipitation / prediction / PROCESS RESPONSES / soil / Soil dynamics / Soil ecology / Soils / Summer / Summer drought / Surficial geology / Synecology / TEMPERATE HEATHLAND / TERRESTRIAL / Terrestrial ecosystems / Warming