Y. Yasumura has conducted a few studies in this beech (Fagus crenata) forest in Hakkoda Mountains in Aomori prefecture in Japan. First she examined nitrogen use efficiency of coexisting canopy and understory species (Yasumura et al. 2002). Next, she examined variation in N resorption in the same coexisitng species in relation to growth irradiance (Yasumura et al. 2005). Thirdly, she examined seasonal changes in some photosythetic traits in sun and shade leaves of an understory woody species (Yasumura et al. in press).
Recently, she examined how the amount of leaf in the canopy and the width of annual ring fluctuated with the occurence of extensive seed production.
Photos are of beech. (Above) Beech trees that almost exclusively occupy the forest canopy. (Below) A beech branch bearing fruits.