Volatile organic compound emmission rates from mixed deciduous and coniferous foest in Northern Wisconsin, USA

Abstract

Biogenic emissions of volatile organic compounds {VOC) from forests play an important role in regulating the atmospheric trace gas composition including global tropospheric ozone concentrations. However, more information is needed on VOC emission rates from different forest regions of the world to understand regional and global impacts and to implement possible mitigation strategies. The mixed deciduous and coniferous forests of northern Wisconsin, USA were predicted to have significant VOC emission rates because they are comprised of many genera (i.e. Picea, Populus, Quercus, Salix) known to be high VOC emitters. In July 1993, a study was conducted on the Chequamegon National Forest near Rhinelander, WI to identify and quantify VOC emitted from major trees, shrubs, and understory herbs in the mixed northern forests of this region. Emission rates were measured at various scales -at the leaf level with cuvettes, the branch level with branch enclosures, the canopy level with a tower based system, and the landscape level with a tethered balloon air sampling system. Area-average emission rates were estimated by scaling, using biomass densities and species composition along transects representative of the study site. Isoprene (C₅H₈) was the primary VOC emitted, although significant quantities of monoterpenes (C₁₀H₁₆) were also emitted. The highest emission rates of isoprene (at 30C and photosynthetically active radiation of 1000 umolm^-2s^-1) were from northern red oak (Quercus rubra. > 110 ug(C)g^-1h^-1): aspen (Populus tremuloides. > 77): willow (Salix spp.. > 54): and black spruce (Picea mariamz. > 101. Emission rates of hybrid poplar clones ranged from 40 to 90 ug(C)g^-1h^-1 at 25C: those of Picea provenances were generally

Citation

Isebrands, J. G.; Guenther, A. B.; Harley, P.; Helmig, D.; Klinger, L.; Vierling, L.; Zimmerman, P.; Geron, C. 1999. Volatile organic compound emmission rates from mixed deciduous and coniferous foest in Northern Wisconsin, USA. Atmospheric Environment. 33: 2527-2536. (1999)