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Anke Jentsch,
Juergen Kreyling, Michael Elmer,
Ellen Gellesch,
Bruno Glaser,
Kerstin Grant,
Roman Hein,
Marco Lara,
Heydar Mirzae,
Stefanie E. Nadler, [......],
Karin Pritsch,
Uwe Rascher,
Martin Schädler,
Michael Schloter,
Brajesh K. Singh,
Jutta Stadler,
Julia Walter,
Camilla Wellstein,
Jens Wöllecke,
Carl Beierkuhnlein
[show abstract]
[hide abstract]
ABSTRACT: Summary1. Studying the effects of climate or weather extremes such as drought and heat waves on biodiversity and ecosystem functions is one of the most important facets of climate change research. In particular, primary production is amounting to the common currency in field experiments world-wide. Rarely, however, are multiple ecosystem functions measured in a single study in order to address general patterns across different categories of responses and to analyse effects of climate extremes on various ecosystem functions.2. We set up a long-term field experiment, where we applied recurrent severe drought events annually for five consecutive years to constructed grassland communities in central Europe. The 32 response parameters studied were closely related to ecosystem functions such as primary production, nutrient cycling, carbon fixation, water regulation and community stability.3. Surprisingly, in the face of severe drought, above- and below-ground primary production of plants remained stable across all years of the drought manipulation.4. Yet, severe drought significantly reduced below-ground performance of microbes in soil indicated by reduced soil respiration, microbial biomass and cellulose decomposition rates as well as mycorrhization rates. Furthermore, drought reduced leaf water potential, leaf gas exchange and leaf protein content, while increasing maximum uptake capacity, leaf carbon isotope signature and leaf carbohydrate content. With regard to community stability, drought induced complementary plant–plant interactions and shifts in flower phenology, and decreased invasibility of plant communities and primary consumer abundance.5. Synthesis. Our results provide the first field-based experimental evidence that climate extremes initiate plant physiological processes, which may serve to regulate ecosystem productivity. A potential reason for different dynamics in various ecosystem services facing extreme climatic events may lie in the temporal hierarchy of patterns of fast versus slow response. Such data on multiple response parameters within climate change experiments foster the understanding of mechanisms of resilience, of synergisms or decoupling of biogeochemical processes, and of fundamental response dynamics to drought at the ecosystem level including potential tipping points and thresholds of regime shift. Future work is needed to elucidate the role of biodiversity and of biotic interactions in modulating ecosystem response to climate extremes.
Journal of Ecology 04/2011; 99(3):689 - 702. · 4.69 Impact Factor
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Anke Jentsch,
Juergen Kreyling, Michael Elmer,
Ellen Gellesch,
Bruno Glaser,
Kerstin Grant,
Roman Hein,
Marco Lara,
Heydar Mirzae,
Stefanie Nadler, [......],
Karin Pritsch,
Uwe Rascher,
Martin Schaedler,
Michael Schloter,
Brajesh Singh,
Jutta Stadler,
Julia Walter,
Camilla Wellstein,
Jens Woellecke,
Carl Beierkuhnlein
[show abstract]
[hide abstract]
ABSTRACT: 1. Studying the effects of climate or weather extremes such as drought
and heat waves on biodiversity and ecosystem functions is one of the
most important facets of climate change research. In particular, primary
production is amounting to the common currency in field experiments
world-wide. Rarely, however, are multiple ecosystem functions measured
in a single study in order to address general patterns across different
categories of responses and to analyse effects of climate extremes on
various ecosystem functions.
2. We set up a long-term field experiment, where we applied recurrent
severe drought events annually for five consecutive years to constructed
grassland communities in central Europe. The 32 response parameters
studied were closely related to ecosystem functions such as primary
production, nutrient cycling, carbon fixation, water regulation and
community stability.
3. Surprisingly, in the face of severe drought, above- and below-ground
primary production of plants remained stable across all years of the
drought manipulation.
4. Yet, severe drought significantly reduced below-ground performance of
microbes in soil indicated by reduced soil respiration, microbial
biomass and cellulose decomposition rates as well as mycorrhization
rates. Furthermore, drought reduced leaf water potential, leaf gas
exchange and leaf protein content, while increasing maximum uptake
capacity, leaf carbon isotope signature and leaf carbohydrate content.
With regard to community stability, drought induced complementary
plant-plant interactions and shifts in flower phenology, and decreased
invasibility of plant communities and primary consumer abundance.
5. Synthesis. Our results provide the first field-based experimental
evidence that climate extremes initiate plant physiological processes,
which may serve to regulate ecosystem productivity. A potential reason
for different dynamics in various ecosystem services facing extreme
climatic events may lie in the temporal hierarchy of patterns of fast
versus slow response. Such data on multiple response parameters within
climate change experiments foster the understanding of mechanisms of
resilience, of synergisms or decoupling of biogeochemical processes, and
of fundamental response dynamics to drought at the ecosystem level
including potential tipping points and thresholds of regime shift.
Future work is needed to elucidate the role of biodiversity and of
biotic interactions in modulating ecosystem response to climate
extremes.
Journal of Ecology. 01/2011; 99(3-0022-0477):689-702.
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[show abstract]
[hide abstract]
ABSTRACT: Climate change will increase the recurrence of extreme weather events such as drought and heavy rainfall. Evidence suggests
that extreme weather events pose threats to ecosystem functioning, particularly to nutrient cycling and biomass production.
These ecosystem functions depend strongly on below-ground biotic processes, including the activity and interactions among
plants, soil fauna, and micro-organisms. Here, experimental grassland and heath communities of three phytodiversity levels
were exposed either to a simulated single drought or to a heavy rainfall event. Both weather manipulations were repeated for
two consecutive years. The magnitude of manipulations imitated the local 100-year extreme weather event. Heavy rainfall events
increased below-ground plant biomass and stimulated soil enzyme activities as well as decomposition rates for both plant communities.
In contrast, extreme drought did not reduce below-ground plant biomass and root length, soil enzyme activities, and cellulose
decomposition rate. The low responsiveness of the measured ecosystem properties in face of the applied weather manipulations
rendered the detection of significant interactions between weather events and phytodiversity impossible. Our data indicate
on the one hand the close interaction between below ground plant parameters and microbial turnover processes in soil; on the
other hand it shows that the plant–soil system can buffer against extreme drought events, at last for the period of investigation.
Plant and Soil 05/2008; 308(1):175-188. · 2.73 Impact Factor
