Welcome to the ENVIRON’s lectures!
On March 9th at 12:00 in Estonian University of Life Sciences, Kreutzwaldi 5 (Metsamaja), room 2C5.
Koike Takayoshi from (Hokkaido University) will give a lecture: Ecophysiology of deciduous trees native to Northeast Asia grown under FACE (Free Air CO2 Enrichment)
We examined the effects of elevated CO2 on the growth and photosynthetic responses of deciduous trees using a Free Air CO2 Enrichment (FACE). In the FACE, photosynthesis was down-regulated in many trees but not alder. Except alder, the leaf nitrogen concentration decreased in high CO2. Alder underwent symbiosis with N-fixing micro-organisms in roots, which act as a sink of photosynthates. Leaves of alder in high CO2 had intensively been grazed by leaf beetles, due to the enhanced leaf N concentration, and these leaves died later. The leaf area index was initially increased by elevated CO2, but the increment was neutralized by time. The light compensation point of the light-photosynthetic curves was declined with an increase in the initial gradient of the curve. In high CO2, the stomatal conductance of most species decreased, increasing the photosynthetic water use efficiency (PWUE). We expected the CO2-induced increase in the PWUE to reduce the size and density of the vessels. However, the vessel size decreased in petioles and current shoots in high CO2, but there was no change in anatomy of stem xylem. We conclude that the whole plant physiology must be studied to provide insight into further changes.