The Response of Soil Processes to Climate Change: Results from Manipulation Studies of Shrublands Across an Environmental Gradient
Citation
Marc Estiarte, Claus Beier, Hanne L Kristensen, Bridget A Emmett, Inger Schmidt, Alwyn Sowerby, Albert Tietema, Dylan Williams, and Josep Penuelas, The Response of Soil Processes to Climate Change: Results from Manipulation Studies of Shrublands Across an Environmental Gradient: .
Summary
Predicted changes in climate may affect key soil processes such as respiration and net nitrogen (N) mineralization and thus key ecosystem functions such as carbon (C) storage and nutrient availability. To identify the sensitivity of shrubland soils to predicted climate changes, we have carried out experimental manipulations involving ecosystem warming and prolonged summer drought in ericaceous shrublands across a European climate gradient. We used retractable covers to create artificial nighttime warming and prolonged summer drought to 20-m 2 experimental plots. Combining the data from across the environmental gradient with the results from the manipulation experiments provides evidence for strong climate controls on soil respiration, [...]
Summary
Predicted changes in climate may affect key soil processes such as
respiration and net nitrogen (N) mineralization and thus key ecosystem
functions such as carbon (C) storage and nutrient availability. To
identify the sensitivity of shrubland soils to predicted climate
changes, we have carried out experimental manipulations involving
ecosystem warming and prolonged summer drought in ericaceous shrublands
across a European climate gradient. We used retractable covers to create
artificial nighttime warming and prolonged summer drought to 20-m 2
experimental plots. Combining the data from across the environmental
gradient with the results from the manipulation experiments provides
evidence for strong climate controls on soil respiration, net N
mineralization and nitrification, and litter decomposition. Trends of
0%–19% increases of soil respiration in response to
warming and decreases of 3%–29% in response to
drought were observed. Across the environmental gradient and below soil
temperatures of 20°C at a depth of 5–10
cm, a mean Q 10 of 4.1 in respiration rates was observed although this
varied from 2.4 to 7.0 between sites. Highest Q 10 values were observed
in Spain and the UK and were therefore not correlated with soil
temperature. A trend of increased accumulated surface litter mass loss
was observed with experimental warming (2%– 22%) but
there was no consistent response to experimental drought. In contrast to
soil respiration and decomposition, variability in net N mineralization
was best explained by soil moisture rather than temperature. When water
was neither limiting or in excess, a Q 10 of 1.5 was observed for net N
mineralization rates. These data suggest that key soil processes will be
differentially affected by predicted changes in rainfall pattern and
temperature and the net effect on ecosystem functioning will be
difficult to predict without a greater understanding of the controls
underlying the sensitivity of soils to climate variables. Published in
Ecosystems, volume 7, issue 6, on pages 625 - 637, in 2004.
