 |
| Titel |
Relative effects of precipitation variability and warming on tallgrass prairie ecosystem function |
| VerfasserIn |
P. A. Fay, J. M. Blair, M. D. Smith, J. B. Nippert, J. D. Carlisle, A. K. Knapp |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 8, no. 10 ; Nr. 8, no. 10 (2011-10-31), S.3053-3068 |
| Datensatznummer |
250006173
|
| Publikation (Nr.) |
 copernicus.org/bg-8-3053-2011.pdf |
|
|
|
|
|
| Zusammenfassung |
| Precipitation and temperature drive many aspects of terrestrial ecosystem
function. Climate change scenarios predict increasing precipitation
variability and temperature, and long term experiments are required to
evaluate the ecosystem consequences of interannual climate variation,
increased growing season (intra-annual) rainfall variability, and warming.
We present results from an experiment applying increased growing season
rainfall variability and year round warming in native tallgrass prairie.
During ten years of study, total growing season rainfall varied 2-fold, and
we found ~50–200% interannual variability in plant growth and
aboveground net primary productivity (ANPP), leaf carbon assimilation
(ACO2), and soil CO2 efflux (JCO2) despite only
~40% variation in mean volumetric soil water content (0–15 cm, Θ15).
Interannual variation in soil moisture was thus amplified in most
measures of ecosystem response. Differences between years in Θ15
explained the greatest portion (14–52%) of the variation in these
processes. Experimentally increased intra-annual season rainfall variability
doubled the amplitude of intra-annual soil moisture variation and reduced
Θ15 by 15%, causing most ecosystem processes to decrease 8–40%
in some or all years with increased rainfall variability compared to
ambient rainfall timing, suggesting reduced ecosystem rainfall use
efficiency. Warming treatments increased soil temperature at 5 cm depth,
particularly during spring, fall, and winter. Warming advanced canopy green
up in spring, increased winter JCO2, and reduced summer JCO2 and
forb ANPP, suggesting that the effects of warming differed in cooler versus
warmer parts of the year. We conclude that (1) major ecosystem processes in
this grassland may be substantially altered by predicted changes in
interannual climate variability, intra-annual rainfall variability, and
temperature, (2) interannual climate variation was a larger source of
variation in ecosystem function than intra-annual rainfall variability and
warming, and (3) effects of increased growing season rainfall variability and
warming were small, but ecologically important. The relative effects of
these climate drivers are likely to vary for different ecosystem processes
and in wetter or drier ecosystems. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|