Validation and Calibration of Riparian Shade Prediction Models Kevin Ceder Mark Teply Cramer Fish Sciences 2013 Western Mensurationists Meeting Leavenworth, WA

Background Alternative stream management zone (SMZ) management can change stream shading –Impact T&E species –Exceed TMDL clean water standards –Shade models used to assess shade loss Idaho Forest Practices Act Advisory Committee (FPAAC) testing new riparian management prescriptions –Want to ensure shade prediction accuracy –Independent studies used to validate and calibrate models –Resulting calibration models used in shade assessments 2013 Western Mensurationists Meeting Leavenworth, WA

Shade Models Physics-based models –“Chen” (Chen et al 1998) –“ODEQ” (Boyd 1996) –Included in Shade.xls (WA Dept. of Ecology) Calculate shade to stream based on light extinction –Input canopy cover and mean height for each zone –Solar paths are known –Assumes continuous cover within zone 2013 Western Mensurationists Meeting Leavenworth, WA

Validation Data Studies Janisch et al. (2012) –6 sites in western WA –50-foot no-cut buffers to WFPA rules Groom et al. (2011) –12 sites in western OR –50- and 75-foot to OAR rules Cupp (pers. Comm. 2012) –8 sites in eastern WA –75-foot to WFPA rules Sugden & Steiner (2005) –9 sites on Plum Creek lands –50-foot 2013 Western Mensurationists Meeting Leavenworth, WA

Biases in Shade Reduction Predictions 2013 Western Mensurationists Meeting Leavenworth, WA

Correlations with Stand Variables ChenODEQ Combined50-foot75-footCombined50-foot75-foot TPA > 3” BA > 3” QMD > 3” Avg. HT > 3” %HWD > 3” Avg. LCR > 3” TPA > 8” BA > 8” QMD > 8” Avg. HT > 8” %HWD > 8” Avg. LCR > 8” RD SUM Western Mensurationists Meeting Leavenworth, WA

Correlations with Stand Variables ChenODEQ Combined50-foot75-footCombined50-foot75-foot TPA > 3” BA > 3” QMD > 3” Avg. HT > 3” %HWD > 3” Avg. LCR > 3” TPA > 8” BA > 8” QMD > 8” Avg. HT > 8” %HWD > 8” Avg. LCR > 8” RD SUM Western Mensurationists Meeting Leavenworth, WA

Shade Loss Calibration Model Shade reduction error related to average crown ratio with 50’ buffers No relationships with stand conditions found for 75’ buffers –3.7% underprediction 2013 Western Mensurationists Meeting Leavenworth, WA

Reasons for Biases 50-foot buffers: –Lower crown ratio stands have more crown to intercept light than higher crown ratio stands. –Extinction coefficient calculation does not take this into account. 75- foot buffers: –Sufficient width for light extinction regardless of canopy –Calculation slightly off Western Mensurationists Meeting Leavenworth, WA

Western Mensurationists Meeting Leavenworth, WA

Western Mensurationists Meeting Leavenworth, WA

Idaho FPAAC SMZ management alternatives We provided support to the FPAAC for several iterations of SMZ management alternatives Learning at each iteration resulted in choosing an alternative that met all their needs 2013 Western Mensurationists Meeting Leavenworth, WA

Summary Shade models are important tools for assessing SMZ management alternatives but show consistent biases Biases can be partially corrected with stream-adjacent stand information It may be time to revisit these models to make them better fit forest conditions 2013 Western Mensurationists Meeting Leavenworth, WA

Questions? Comments? Kevin Ceder: Mark Teply: 2013 Western Mensurationists Meeting Leavenworth, WA

References Boyd, M.S Heat Source: stream temperature prediction. Master’s Thesis. Departments of Civil and Bioresource Engineering, Oregon State University, Corvallis, Oregon. Chen, Y.D., R.F. Carsel, S.C. McCutcheon, and W.L. Nutter Stream temperature simulation of forested riparian areas: I. watershed- scale model development. Journal of Environmental Engineering. April pp Groom J. D., L. Dent, L. Madsen, J. Fleuret Response of western Oregon (USA) stream temperatures to contemporary forest management. Forest Ecology and Management 262(8): Janisch, J. E., S. M. Wondzell, and W. J. Ehinger Headwater stream temperature: Interpreting response after logging, with and without riparian buffers, Washington, USA. Forest Ecology and Management, doi: /j.foreco Sugden, B. and R. Steiner Effectiveness of native fish HCP buffers for stream temperature control: 5-year review report to US Fish and Wildlife Service. Plum Creek Timber Company, Columbia Falls, MT Western Mensurationists Meeting Leavenworth, WA