Title: Data set 2: Logjam data, associated with ‘All Logjams Are Not Created Equal’ Abstract: Logjams create diverse physical and ecological effects in stream channels, including at least temporary storage of water, sediment, and particulate organic matter. We hypothesize that logjams that span the entire bankfull channel width in channels < 25 m wide are more effective in storing these materials than non-channel spanning logjams. We test this hypothesis by systematically comparing characteristics of 183 logjams from 17 stream reaches in the Southern Rocky Mountains. Our dataset is novel in that it evaluates naturally occurring logjams in unaltered streams in a single study area specifically based on whether they span the stream channel. We find that channel-spanning logjams have a significantly larger number of wood pieces, longer & wider pieces, more ramp and bridge pieces, and greater logjam height and volume, both as raw data and when standardized by average channel width. Channel-spanning logjams also have significantly greater backwater pool volume and volume of particulate organic matter stored in backwater pools and in logjams. Restoration employing engineered logjams in relatively small channels currently focuses on non-spanning logjams, but could be expanded to include spanning logjams. Contact: Bridget Livers Email and/or phone number for contact person: bridgetlivers@gmail.com License information or restrictions placed on the data: CC0 (public domain) Recommended data citation Format of data files: .csv Location where data were collected: Rocky Mountain National Park, Colorado, USA; Lat: 40.3333, Long: -105.7000; locations of each logjam are included in file Time period during which data were collected: 2013-06-01 to 2013-07-31; 2014-06-01 to 2014-07-31 File Information: File name ‘Dataset S2’. One dataset as a table, raw and calculated data. Variable information: * Reach: name used for segment of stream surveyed (reach); usually an abbreviation of stream name; CONYc = Cony Creek (confined reach), CONYu = Cony Creek (unconfined reach), GC = Glacier Creek, GLACIERu = Glacier Creek (unconfined reach), HUNTERSc = Hunters Creek (confined reach), HUNTERSu = Hunters Creek (unconfined reach), MILLc = Mill Creek (confined reach), MILLu = Mill Creek (unconfined reach), NSVC = North St. Vrain Creek (confined), NSVH = North St. Vrain Creek (highest unconfined reach), NSVL = North St. Vrain Creek (lower unconfined reach), NSVpc = North St. Vrain Creek (partly confined reach), NSVU = North St. Vrain Creek (middle unconfined reach), OUZELa-c,u = Ouzel Creek reaches (letters not representative of other descriptors) * Jam: name/number of jam within stream reach * N: latitude of jam (decimal degrees, northing) * W: longitude of jam (decimal degrees, negative indicates west of Greenwich) * DA (km2): drainage area of upstream end of stream reach (not individual jam), in square kilometers; acquired using USGS Stream Stats (Ries et al., 2017) * Forest age: age of riparian forest; Old = old growth, Young = younger forest * Position: describes whether a jam is channel spanning (spanning), or not channel-spanning (not) * Avg width (m): mean individual stream reach width from several measurements, accounts for width of each channel in multithread stream segments * Basal area (m2/ha): mean forest cover of stream reach; measured with Panama basal area angle gage, which uses counted number of trees from stream bank, averaged from several measurements * Gradient (m/m): mean gradient of stream reach from several measurements * Confinement: categorical, describes how confined stream reach is within its valley, determined by mean valley width/mean stream width; confined (C) = confinement <3, partly confined (P) = confinement between 3-8, unconfined (U) = confinement >8 * Confinement ratio: continuous value, describes how confined stream reach is within its valley, determined by mean valley width/mean stream width * Multithread: describes planform of stream reach; if reach has multiple, parallel channels (multithread = Y), if reach is single channel (single-thread, multithread = N) * Obstruction ratio: describes extent to which jam obstructs stream channel (m/m), width of jam divided by mean channel width * Pieces: number of large wood pieces in jam; large wood minimum size is 0.1m diameter, 1m length * Height: height of jam (m) * Porosity: visually estimated proportion of jam that is void space (i.e. not occupied by wood or organic matter), where jam is visualized as a best-fit box as measured by height, width, and length * # bridges and ramps: total number of large wood pieces in jam oriented in channel as bridges (both ends on stream banks) or ramps (one end on stream bank) * Proportion decayed and rotten: proportion of large wood pieces in jam classified in the field as being decayed (somewhat decomposed), to rotten (falling apart, easily broken into smaller pieces) * Proportion rotten: proportion of large wood pieces in jam classified in the field as being rotten (falling apart, easily broken into smaller pieces) * Mean diameter: mean diameter of all measured large wood pieces in jam (m) * Mean length: mean length of all measured large wood pieces in jam (m) * Max diameter: maximum diameter of all measured large wood pieces in jam (m) * Max length: maximum length of all measured large wood pieces in jam (m) * SD piece length: standard deviation of large wood piece lengths in jam * SD piece diameter: standard deviation of large wood piece diameters in jam * SD piece volume: standard deviation of large wood piece volumes in jam * Wood volume: total large wood volume in jam (m3), as the sum of all wood piece volumes in jam * Pool: if backwater pool, Y; no backwater pool, N * Pool volume: total backwater pool volume behind jam (m3), using mean of multiple measurements of length, depth, and width of pool * Pool OM vol: total volume of organic matter (OM) stored in backwater pool behind jam (m3), using mean of multiple measurements of length, depth, and width of OM in pool * OM vol: total volume of organic matter (OM) stored within the jam matrix (m3), visually estimated as a proportion of jam that is OM (i.e. not by wood or void space), where jam is visualized as a best-fit box as measured by height, width, and length * Wood vol/ch width: unit wood volume (m3/m); total wood volume in jam divided by average channel width * Height/ ch width: unit height (m/m); jam height divided by average channel width * Max length/ ch width: maximum wood piece length divided by average channel width (m/m) * Avg length/ ch width: average wood piece length divided by average channel width (m/m) * Jam OM vol/ ch width: unit jam OM volume (m3/m); total volume of organic matter (OM) stored within the jam matrix divided by average channel width * Pool vol/ ch width: unit pool volume (m3/m); total backwater pool volume behind jam divided by average channel width * Pool OM/ch width: unit pool organic matter (OM) volume (m3/m); total volume of organic matter (OM) stored in backwater pool behind jam divided by average channel width * Proportion bridge and ramp pieces: proportion of total large wood pieces in jam oriented in channel as bridges (both ends on stream banks) or ramps (one end on stream bank) * # pieces/ ch width: number of large wood pieces in jam divided by average channel width Method(s): Unless otherwise noted in ‘Variable information’, data was collected with a TruPulse 350B laser rangefinder with horizontal accuracy of +/- 0.1m or measured by hand with measuring tape. Data was inputted into Microsoft Excel to attain means, proportions, values normalized by length, and volumes of wood using the formula for a cylinder using measured average diameter and length of wood pieces. Detailed methods described in Livers and Wohl, 2016, Table 1: Livers, B., and E. Wohl, 2016. Sources and interpretation of channel complexity in forested subalpine streams of the Southern Rocky Mountains. Water Resources Research 52, 3910-3929. https://doi.org/10.1002/2015WR018306. Software: All data are raw data or summed or averaged data using Microsoft excel Limitations to reuse: None Are there multiple versions of the dataset? No Related materials: Data set 1: Characteristics of Study Reaches, associated with ‘All Logjams Are Not Created Equal’ Data source: Ries, K.G., III, Newson J.K., Smith, M.J., Guthrie, J.D., Steeves, P.A., Haluska, T.L., Kolb, K.R., Thompson, R.F., Santoro, R.D., and Vraga, H.W., 2017, StreamStats, version 4: U.S. Geological Survey Fact 2017–3046, 4 p., https://doi.org/10.3133/fs20173046. [Supersedes USGS Fact Sheet 2008–3067.] Related Files: None