Andrew P. Stubblefield

Catalyzing frontiers in water-climate-society research: A view from early career scientists and junior faculty

AMEriCAN METEOrOlOGiCAl SOCiETY | 477 AffiliAtions: McNeeley, TesseNdorf, aNd lazrus—NCAR, Boulder, Colorado; lazrus—University of Oklahoma, Norman, Oklahoma; Heikkila—University of Colorado, Denver, Colorado; fergusoN—Colorado School of Mines, Golden, Colorado; arrigo—East Carolina University, Greenville, North Carolina; aTTari—Columbia University, New York, New York; ciaNfraNi— Hampshire College, Amherst, Massachusetts; dilliNg aNd kircHoff—University of Colorado, Boulder, Colorado; gurdak— San Francisco State University, San Francisco, California; kaMpf—Colorado State University, Fort Collins, Colorado; kauNeckis—University of Nevada, Reno, Nevada; lee—San Jose State University, San Jose, California; liNTNer—Rutgers, The State University of New Jersey, New Brunswick, New Jersey; MaHoNey—UCAR, Boulder, Colorado; opiTz-sTapleToN— Institute for Social and Environmental Transition, Boulder, Colorado; ray—University of Hawaii at Manoa, Honolulu, Hawaii; souTH—University of Exeter, Exeter, United Kingdom; sTubblefield—Humboldt State University, Arcata, California; brugger—University of California—Davis, Davis, California CoRREsPonDinG AUtHoR: Shannon M. McNeeley, Advanced Study Program, Research Applications Laboratory/Integrated Science Program, NCAR, P.O. Box 3000, Boulder, CO 80307 E-mail: smcneele@ucar.edu

Channel Adjustment Following Culvert Removal from Forest Roads in Northern California, USA

Forest roads can be a major contributor of sediment entering streams and estuaries. Road restoration and removal has been shown to be effective in reducing sediment delivery over decadal time spans. However, few studies have been conducted to quantify and characterize short-term (1–3 yr) channel adjustment after removal of stream crossing fill material and reconstruction of former stream channels. This evaluation is important for managers needing to assess impacts, cost, and benefits of stream crossing removal. This study examines 20 road stream crossings by surveying channel adjustments and determining rilling and gullying delivery volumes, channel substrate changes, and the role of rock placed in reconstructed channels at Redwood National and State Parks, California, USA. Erosion and channel incision were significantly higher at crossings in the 1st year following removal than at older crossings. First year crossings yielded an average of 7.71 m3 of erosion per crossing, while the 2nd- and 3rd-year crossings showed a net gain of 0.08 m3 of sediment (indistinguishable from 0). Eighty-six percent of the erosion could be attributed to channel incision and bank erosion. The remaining 14% originated from rilling, gullying, and side-slope failures. Coarsening of channel substrate was most pronounced in the 1st year after removal, and the 1st storms of the year were most important in mobilizing sediment. This study underlines the importance of excavating to bedrock or coarse material when recreating a streambed, and the identification of bulges (short convex segments) in the channel profile that are likely to erode.

Observations of Channel Change from Constructed Wood Jams on a Forested Gravel-Bed Stream

AbstractSalmonids in the Pacific Northwest face a number of threats: habit degradation, loss of habitat, overharvest, competition from hatchery fish, dams, and climate change. Wood has been shown to play a key role in many aspects of stream habitat quality; however, it is in low supply in many Pacific Northwest streams because of wood removal and timber harvest practices in riparian zones. Wood placement for restoration has the potential to benefit salmonid populations. However, common applications often fall short of producing the physical changes necessary to achieve the objectives, such as the formation of deep pools and cover. This study evaluated the hypothesis that wood jams constructed with whole-tree materials, high wood piece counts, and high wood volumes would be effective at creating instream geomorphic complexity, function, and aquatic habitat quality. Results were based on an evaluation of changes to surface sediment textures and channel morphology at eight constructed wood jams built with va...