Ozone effacts on growth and productivity of Populus tremuloides Michx.: A comparison of results from OTC, FACE, and ozone gradient studies with a common set of genetic materials

Wien

Natural Hazards and Landscape Federal Research and Training Centre for Forsts

2006

1 Abb., 3 Tab.

Unselbständiges Werk

200134518

Proceedings on the workshop "Critical Levels of Ozone: Further Applying and Developing the Flux-based Concept" 15-19 November 2005 Obergurgl, Tyrol, Austria, 1 Abb., 3 Tab.

Tropospheric ozone (O3) effects on forest trees have been studied intensely for the past 50 years. Yet, it remains very difficult to predict how long-term forest tree growth and productivity are affected by O3. Here we provide a comparison of results of three growth and productivity studies of O3 impacts trembling aspen (Populus tremuloides Michx.) that were done with an identical set of genetic materials (clone 216 = intermediate in O3 tolerance; clone 259 = O3 sensitive; and clone 271 = O3 tolerant) over the past 15 years. The studies were done in open-top chambers, an openair (FACE) system, and along a natural gradient in the Lake States region of the United States. Here, we will compare a suite of responses from foliar to growth and productivity across these three studies. It is our contention that O3 at current levels is limiting the CO2 sink strength of trembling aspen, the most widely distributed tree species in North America, across much of its range.