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This study explores the effects of atmospheric CO2 enrichment and climate change on soil moisture (W
r
) and biome-level water limitation (L
TA), using a dynamic global vegetation and water balance model forced by five different scenarios of change in temperature,
precipitation, radiation, and atmospheric CO2 concentration, all based on the same IS92a emission scenario. L
TA is defined as an index that quantifies the degree to which transpiration and photosynthesis are co-limited by soil water
shortage (high values indicate low water limitation). Soil moisture decreases in many regions by 2071–2100 compared to 1961–1990,
though the regional pattern of change differs substantially among the scenarios due primarily to differences in GCM-specific
precipitation changes. In terms of L
TA, ecosystems in northern temperate latitudes are at greatest risk of increasing water limitation, while in most other latitudes
L
TA tends to increase (but again varies the regional pattern of change among the scenarios). The frequently opposite direction
of change in W
r
and L
TA suggests that decreases in W
r
are not necessarily felt by actual vegetation, which is attributable mainly to the physiological vegetation response to elevated
CO2. Without this beneficial effect, the sign of change in L
TA would be reversed from predominantly positive to predominantly negative. 相似文献
2.
Wolfgang Lucht Sibyll Schaphoff Tim Erbrecht Ursula Heyder Wolfgang Cramer 《Carbon balance and management》2006,1(1):6-7
Background
Dynamic Global Vegetation Models (DGVMs) compute the terrestrial carbon balance as well as the transient spatial distribution of vegetation. We study two scenarios of moderate and strong climate change (2.9 K and 5.3 K temperature increase over present) to investigate the spatial redistribution of major vegetation types and their carbon balance in the year 2100. 相似文献3.
Sibyll Schaphoff Wolfgang Lucht Dieter Gerten Stephen Sitch Wolfgang Cramer I. Colin Prentice 《Climatic change》2006,74(1-3):97-122
This study investigates commonalities and differences in projected land biosphere carbon storage among climate change projections derived from one emission scenario by five different general circulation models (GCMs). Carbon storage is studied using a global biogeochemical process model of vegetation and soil that includes dynamic treatment of changes in vegetation composition, a recently enhanced version of the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM). Uncertainty in future terrestrial carbon storage due to differences in the climate projections is large. Changes by the end of the century range from −106 to +201 PgC, thus, even the sign of the response whether source or sink, is uncertain. Three out of five climate projections produce a land carbon source by the year 2100, one is approximately neutral and one a sink. A regional breakdown shows some robust qualitative features. Large areas of the boreal forest are shown as a future CO2 source, while a sink appears in the arctic. The sign of the response in tropical and sub-tropical ecosystems differs among models, due to the large variations in simulated precipitation patterns. The largest uncertainty is in the response of tropical rainforests of South America and Central Africa. 相似文献
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