Plant Responses to Rising Atmospheric Carbon Dioxide

Development of experimental structure and influence of high CO2 concentration in maize cro

“…Although the net photosynthesis (A) did not present statistical difference in the second measurement between P1 and P2 (Table 2),plants subjected to P1 treatment showed higher photosynthetic rates in the two measurements, 27.03 and 32.02% respectively higher than P3, thus responding positively to the increase of [CO 2 ]. This result indicates that C 4 -type plants may respond to increased [CO 2 ] in the environment, unlike the findings by TAIZ & ZEIGER (2004) and ZISKA & BUNCE (2006), who reported that C 4 plants do not benefit from increased [CO 2 ] in the atmosphere. Nevertheless, PRITHCARD & AMTHOR (2005) mentioned that the C 4 plants benefit from increases of [CO 2 ], although not directly increasing the photosynthetic rate, but through the reduction in stomatal conductance (Gs) and transpiration (Table 2).…”

“…In general, [CO 2 ] 200-400 ppm higher than normal produces stimuli in growth and production of C 3 -type plants, but not in C 4 -type crops, because increase in the [CO 2 ] have little effect on photosynthetic rates of C 4 plants, due to the mechanism that increases the [CO 2 ]on the site of action of Rubisco from these plants (ZISKA & BUNCE, 2006). Maize (Zea mays L.) is a C 4 plant that generally tends to present little or no additional growth in response to elevated [CO 2 ] (GHANNOUM et al, 2000).…”

Future CO2-Induced Ocean Acidification Mediates the Physiological Performance of a Green Tide Alga

“…For terrestrial green plants, short-term exposures to increased CO 2 levels stimulate the net photosynthesis of both C 3 and even some C 4 plants (Ziska and Bunce, 2006), while long-term exposures to elevated CO 2 concentration often lead to a declined photosynthetic rate in many plant species (Thomas and Strain, 1991). Dark respiration and photorespiration are also reduced at the leaf level, while plant growth is stimulated (Bunce, 2004).…”

Physiological and biochemical responses of diatoms to projected ocean changes

“…Increasing C:N ratios imply more carbon may be removed to the deep sea by the 'biological pump' relative to the amount of nitrogen consumed by phytoplankton, which has potential implications for the global carbon cycle as well as for increases in deep water hypoxia (Riebesell et al 2007). Higher C:N ratios also reflect lower nutritional value of phytoplankton-produced organic matter (Ziska & Bunce 2006), which may affect the efficiency of bacterial degradation and zooplankton reproduction, thus having further implications for marine biogeochemical processes (Riebesell et al 2007). Si availability is a key factor in regulation of diatom growth in open oceans, and this group dominates the biogeochemical cycling of Si.…”