Forest-atmosphere BVOC exchange in diverse and structurally complex canopies: 1-D modeling of a mid-successional forest in northern Michigan

Journal Article · Sun Nov 01 00:00:00 EDT 2015 · Atmospheric Environment (1994)

DOI:https://doi.org/10.1016/j.atmosenv.2015.08.094· OSTI ID:1243233

Bryan, Alexander M.; Cheng, Susan J.; Ashworth, Kirsti; Guenther, Alex B.; Hardiman, Brady; Bohrer, Gil; Steiner, A. L.

Foliar emissions of biogenic volatile organic compounds (BVOC)dimportant precursors of tropospheric ozone and secondary organic aerosolsdvary widely by vegetation type. Modeling studies to date typi-cally represent the canopy as a single dominant tree type or a blend of tree types, yet many forests are diverse with trees of varying height. To assess the sensitivity of biogenic emissions to tree height vari-ation, we compare two 1-D canopy model simulations in which BVOC emission potentials are homo-geneous or heterogeneous with canopy depth. The heterogeneous canopy emulates the mid-successional forest at the University of Michigan Biological Station (UMBS). In this case, high-isoprene-emitting fo-liage (e.g., aspen and oak) is constrained to the upper canopy, where higher sunlight availability increases the light-dependent isoprene emission, leading to 34% more isoprene and its oxidation products as compared to the homogeneous simulation. Isoprene declines from aspen mortality are 10% larger when heterogeneity is considered. Overall, our results highlight the importance of adequately representing complexities of forest canopy structure when simulating light-dependent BVOC emissions and chemistry.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1243233
• Report Number(s): PNNL-SA-115254; KP1704020
• Journal Information: Atmospheric Environment (1994), Vol. 120; ISSN 1352-2310
• Publisher: Elsevier
• Country of Publication: United States
• Language: English