A COMPATATIVE STUDY ON RELATION BETWEEN PHOTOSYNTHETIC RATE OF ANEUROLEPIDIUM CHINENSE AND STIPA GRANDIS AND AIR TEMPERATURE AT THEIR DIFFERENT PERIODS OF GROWTH
不同生长时期羊草大针茅光合速率与气温关系的比较研究

This paper focuses on the relation between photosynthetic rates andair temperature in A.chinense and S. grandis in the beginning, the peakand the late period of their growth. The results are as follows. For A.chinense, the relation between photosynthetic rate and tempera-ture shows a curve of cubic function, wheweas for S. grandis it is a cur-ve of quartic function. Compared with A.chinense,the compensation pointof photosynthesis at lower temperature in S. grandis is higher, and athigher temperature, this value is lower in S. grandis than in A.chinense.But the slopes for the two curves show little difference. At different growth stages,the indices for photosynthesis mentionedabove show a little change. They reach the highest values of compensa-tion point of photosynthesis at higher temperature and the optimal tempe-rature at the peak growth stage. Compared with the beginning stage, the-se values for the late growth stage are lower. At the half-saturation and near-saturation points, the air temperatureof photosynthetic rate is highest in peak growth stage. At the other twostages,the late stage is lower than the beginning for the two species inthe decreasing section of the curve and in increasing section of the curvefor S.grandis, it is the same with the decreasing section, but for A.chinense,it is just the opposite.