Effect of elevated levels of atmospheric CO2 on plant-insect interaction A preliminary study on C3 and C4 plants in the Northeast stepps and their ecological distribution A REVIEW OF ADAPTABLE VARIATIONS AND EVOLUTION OF PHOTOSYNTHETIC CARBON ASSIMILATING PATHWAY IN C3 AND C4 PLANTS Identification of the Photosynthetic Pathways of 30 Plant Species in the Subalpine Meadow of the Qinling Mountains,China Effect of the amount of C3 or C4 plants in diets on the quality and main chemical components of beef