PARENT SESSION
Poster Session 1: Photosynthesis and Water Relations
Monday, August 8, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal
Does parent tree age affect growth and gas exchange in grafted seedlings?
Vanderklein, Dirk*,1, Martinez-Vilalta, Jordi2, Mencuccini, Maurizio2, 1 Montclair State University, Montclair, NJ, USA2 University of Edinburgh, Edinburgh, UK
ABSTRACT- The effect of age on growth and gas exchange was tested on grafted seedlings of Scots pine (Pinus sylvestris). Grafted scions were collected from parent trees ranging in age from 39 to 269 years and growing within a kilometer of each other. Grafting took place four years prior to the study and most of the above ground growth was scion derived. We could not find any effect of parent tree age on any growth, gas exchange or hydraulic conductance parameter that we tested. Instead, we found an inverse effect of seedling size on gas exchange. Larger seedlings had lower rates of photosynthesis, stomatal conductance and transpiration, but hydraulic conductance was not affected. We found no evidence that grafting per se or pot size had any effect on our results. Seedlings with larger crowns also had wider needles, which may have higher resistances to vapor flow. We conclude then, that age had no effect on whole seedling function, but that leaf-level factors affected physiology instead.
Key words: Tree age, Gas exchange, Hydraulic conductance, Pinus sylvestris