INTERACTIONS BETWEEN C-3 AND C-4 SALT-MARSH PLANT-SPECIES DURING 4 YEARS OF EXPOSURE TO ELEVATED ATMOSPHERIC CO2
INTERACTIONS BETWEEN C-3 AND C-4 SALT-MARSH PLANT-SPECIES DURING 4 YEARS OF EXPOSURE TO ELEVATED ATMOSPHERIC CO2
复制标题
DOI：
10.1007/bf00048149
复制
发表时间：
1993-01-01
期刊：
影响因子：
--
通讯作者：
WHIGHAM, DF
中科院分区：
文献类型：
--
作者：
ARP, WJ;DRAKE, BG;WHIGHAM, DF
已知大气CO2浓度升高会刺激C3途径植物的光合作用和生长，但对C4途径植物的影响较小。因此，预计CO2浓度的增加将改变C3和C4物种之间的竞争性相互作用。长期暴露于CO2浓度升高（环境CO2浓度+340 mumolCO 2 mol-1）的盐沼植被与C3和C4物种的影响进行了研究。CO2浓度升高增加了纯林中C3莎草的生物量，而C4草种大米草在单种群落中的生物量没有受到影响。在C3/C4混合群落中，C3莎草的生物量在CO2浓度升高时相对增加，而C4莎草的生物量则下降，C4莎草主要分布在盐沼的高海拔地区，C3莎草主要分布在低海拔地区，混合群落则分布在中海拔地区。在较高海拔地区，干旱和盐胁迫可能限制了藨草的生长，而在较低海拔地区，米草的生长可能受到较高频率的洪水的影响。CO2浓度升高可能会影响盐沼中的物种分布，如果它允许藨草生长在更高的海拔，它反过来可能会影响米草的生长。
Elevated atmospheric CO2 is known to stimulate photosynthesis and growth of plants with the C3 pathway but less of plants with the C4 pathway. An increase in the CO2 concentration can therefore be expected to change the competitive interactions between C3 and C4 species. The effect of long term exposure to elevated CO2 (ambient CO2 concentration + 340 mumol CO2 mol-1) on a salt marsh vegetation with both C3 and C4 species was investigated. Elevated CO2 increased the biomass of the C3 sedge Scirpus olneyi growing in a pure stand, while the biomass of the C4 grass Spartina patens in a monospecific community was not affected. In the mixed C3/C4 community the C3 sedge showed a very large relative increase in biomass in elevated CO2 while the biomass of the C4 species declined.The C4 grass Spartina patens dominated the higher areas of the salt marsh, while the C3 sedge Scirpus olneyi was most abundant at the lower elevations, and the mixed community occupied intermediate elevations. Scirpus growth may have been restricted by drought and salt stress at the higher elevations, while Spartina growth at the lower elevations may be affected by the higher frequency of flooding. Elevated CO2 may affect the species distribution in the salt marsh if it allows Scirpus to grow at higher elevations where it in turn may affect the growth of Spartina.