| |
| Web URL(s): | http://www.jstor.org/stable/2269435
Last checked: 03/09/2016
Requires: PDF Reader
Access conditions: Item is within a limited-access website |
|---|
| Author(s): | Coughenour, Michael B.;
Chen, De-Xing |
|---|
| Author Affiliation: | Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, Colorado |
|---|
| Title: | Assessment of grassland ecosystem responses to atmospheric change using linked plant-soil process models |
|---|
| Section: | Inferential studies of climate change
Other records with the "Inferential studies of climate change" Section
|
|---|
| Source: | Ecological Applications: A publication of the Ecological Society of America. Vol. 7, No. 3, August 1997, p. 802-827. |
|---|
| Publishing Information: | Washington, DC: Ecological Society of America |
|---|
| # of Pages: | 26 |
|---|
| Keywords: | TIC Keywords: Models; Grasslands; Atmosphere; Environmental factors; Ecosystems; Temperatures; Carbon dioxide; Precipitation; Growth; Nitrogen; Nutrient uptake; Mineralization; Decomposition; Photosynthesis
|
|---|
| Abstract/Contents: | "Models of photosynthesis, plant growth, and biophysical processes were linked with models that simulate water, nutrient, and carbon flows through plant-soil ecosystems. The linked ecosystem model was applied to examine ecosystem-level responses to CO2, temperature, precipitation, and global-warming scenarios in grasslands of Colorado and Kansas, USA, and Kenya. The model predicted that increased temperatures would decrease primary production at current CO2 levels, but decreases were reversed by doubling atmospheric CO2 concentration. Greater increases in daily minimum temperatures than daily maximum temperatures mitigated reductions in photosynthesis and water-use efficiency (WUE) later in the day, more than offseting increases in nighttime respiration rates under warmer temperatures. A temperature increase of 5°C reduced organic carbon in grassland soils by 20-30%, through effects on plant growth and decomposition, but the doubled CO2 negated soil carbon losses by increasing plant growth. Under higher precipitation and doubled CO2, soil carbon stocks increased, or decreased little, in response to warmer temperatures. Doubling CO2 increased net primary production (NPP) by 31-45% in a simulated Colorado C4 grassland, by 20-70% in a Colorado C3 grassland, by 23-31% in a Kansas C4 grassland, and by 23-35% in a Kenya C4 grassland at ambient precipitation levels. Growth was shifted belowground, thus weakening aboveground responses. Higher temperatures strengthened the positive NPP responses to CO2. Larger positive responses to elevated CO2 were modeled under drier conditions, and smaller responses were modeled under wetter conditions. NPP increases under elevated CO2 were mostly caused bye increased plant WUE at all sites, which was brought about by partial stomatal closure. Decreased N concentrations in plant litter under elevated CO2 slowed N mineralization, but greater plant production and thus greater litter inputs into the soil under elevated CO2 offset the negative effects of lower litter quality. Decreases in plant N concentration under elevated CO2 also reduced plant N requirements. At current atmospheric CO2 (350 μmol/mol), a general circulation model (GCM) climate-change scenario decreased NPP and soil organic matter (SOM) in Colorado but not in Kansas or Kenya. A second GCM climate-change scenario either effected NPP and SOM little, or increased NPP and SOM at current CO2. NPP and SOM responses in the simulated grasslands were very sensitive to precipitation which GCMs predict with relatively low confidence. Doubled CO2 partially or completely offset decreases in NPP and SOM under climate-change scenarios." |
|---|
| Language: | English |
|---|
| References: | 135 |
|---|
| Note: | Figures
Tables
Graphs
Diagrams |
|---|
| ASA/CSSA/SSSA Citation (Crop Science-Like - may be incomplete):
Coughenour, M. B., and D.-X. Chen. 1997. Assessment of grassland ecosystem responses to atmospheric change using linked plant-soil process models. Ecol. Appl. 7(3):p. 802-827. |
| Fastlink to access this record outside TGIF: https://tic.msu.edu/tgif/flink?recno=115495 |
| If there are problems with this record, send us feedback about record 115495. |
| Choices for finding the above item: |
|---|
| Web URL(s):
http://www.jstor.org/stable/2269435
Last checked: 03/09/2016
Requires: PDF Reader
Access conditions: Item is within a limited-access website |
| 
MSU catalog number: QH 540 .E273 |
| Find from within TIC:
Digitally in TIC by record number. |
| Request through your local library's inter-library loan service (bring or send a copy of this TGIF record) |
