How might an introduced plant species kill native plant species?

Which plant/species performs the "best" at photosynthesis? I'm looking for ~CO2 converted vs. mass of plant

• Which plant/species performs the "best" at photosynthesis? with all other conditions being equal, what would be the best plant to perform the photosynthesys cycle (convert CO2 to O2) my metric would be something like CO2 converted vs. mass / size of the plant. Would the plant be different in an atmosphere with a higher CO2 concentration?

• Answer:

  C4 plants (e.g. maize, sugar cane) photosynthesize better than C3 plants (e.g. wheat rice). The C4 advantage is due to a mechanism that enriches the CO2 concentration around Rubisco, the most important enzyme in photosynthesis, causing it to be more efficient. The advantage of C4 plants over C3 plants will be lost as global CO2 concentrations increase.