Photosynthesis can acclimate to a wide range of temperature. With the rise in global temperature the question how acclimation occurs has become more prominent. Because of the large nitrogen invested in photosynthetic proteins photosynthesis is often strongly correlated to leaf nitrogen content. However, nitrogen is assumed limited in most ecosystems. I questioned how photosynthetic acclimation relates to leaf nitrogen content in environments with different temperature. Temperature varied either naturally, with seasons and latitude, or experimentally. For the evergreen understory shrub Aucuba japonica I will show what determines the increase in leaf nitrogen content in winter and where it is located. For Fagus crenata I will show why the leaf nitrogen content increases from northern to southern populations grown in a common garden. For Quercus crispula I will show that when soil temperature is increased the leaf nitrogen content decreased in the first year of the experiment. Nevertheless these different responses of leaf nitrogen content to temperature I will show that there is consequent trend in how leaf nitrogen content changes in relation to photosynthetic capacity, which I will explain in more detail in the coming trendy seminar.