Data and code from: Climate-driven brook trout invasions in shifting bull trout habitat: An application of spatial-stream-network modeling
Data files
Jul 28, 2026 version files 6.85 MB
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Conditioning_RME_metrics_for_MediumRes_NHD_flowlines.R
5.02 KB
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README.md
10.87 KB
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Voss_BKT_SSN_analysis_final.R
81.87 KB
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Voss_BKT_SSN_CandModelFixedEffectTerms.xlsx
15.55 KB
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Voss_etal_bkt_preds_csv.zip
2.19 MB
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Voss_etal_bkt_preds_shp.zip
4.55 MB
Jul 28, 2026 version files 6.85 MB
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Conditioning_RME_metrics_for_MediumRes_NHD_flowlines.R
5.02 KB
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README.md
10.76 KB
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Voss_BKT_SSN_analysis_final.R
81.87 KB
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Voss_BKT_SSN_CandModelFixedEffectTerms.xlsx
15.55 KB
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Voss_etal_bkt_preds_csv.zip
2.19 MB
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Voss_etal_bkt_preds_shp.zip
4.55 MB
Abstract
This Dryad submission is associated with the Ecosphere article by Voss et al. (2026) "Climate-driven brook trout invasions in shifting bull trout habitat: an application of spatial-stream-network modeling". Nonnative brook trout (Salvelinus fontinalis) threaten cold-adapted native salmonids throughout western North America, and the extent of future invasions in coldwater streams is recognized as an area of uncertainty with important consequences. We addressed this uncertainty using spatial-stream-network (SSN) modeling to develop a species distribution model (SDM) for brook trout in Idaho, creating high-resolution prediction maps of suitable (i.e., invadable) habitat under baseline (1990–2015) and future (2080s) climate scenarios, and querying predictions within natal bull trout (S. confluentus) habitat patches (stream–subwatershed scale) for each scenario. Results indicated that brook trout will experience a net loss of suitable habitat in Idaho, but a large increase of suitable habitat in cold streams. The total proportion of bull trout habitat invadable by brook trout increased from 0.33 during the baseline scenario to 0.44 during the future scenario—a result of upstream expansions of brook trout habitat that were partially offset by contractions in bull trout habitat. Climate change will broadly increase the threat that brook trout pose to bull trout, but the degree of change experienced by individual populations will vary with local context. The high-resolution predictions created by our SSN model can help conservation planners identify and prioritize control efforts on the small proportion of brook trout populations that most threaten bull trout.
Dataset DOI: 10.5061/dryad.7wm37pw7d
Description of the data and file structure
This Dryad submission contains (i) the R script and Excel files used to produce the results of this investigation, and (ii) the spatially explicit Brook Trout predictions produced by our SSN model in CSV and ArcGIS shapefile format.
Fish survey data analyzed in this manuscript are the property of the Idaho Department of Fish and Game, U.S. Forest Service, U.S. Bureau of Reclamation, and Idaho Power Company. The authors will gladly facilitate third-party data requests to proprietary owners of survey data upon request.
The file Voss_BKT_SSN_analysis_final.R contains the R code used to create the results, tables, and figures associated with the submitted manuscript "Climate-driven brook trout invasions in shifting bull trout habitat: an application of spatial-stream-network modeling". The file Voss_BKT_SSN_CandModelFixedEffectTerms.xlsx contains the model structures for each candidate model created in Voss_BKT_SSN_analysis_final.R. There is no data contained in Voss_BKT_SSN_CandModelFixedEffectTerms.xlsx; it is simply a 'shortcut' created to avoid repetitively specifying similar models in the R console. The file Conditioning_RME_metrics_for_MediumRes_NHD_flowlines.R contains an R script capable of conditioning Riverscape Metrics Engine (RME; https://data.riverscapes.net) stream habitat metrics for compatibility with NORWEST stream flowline segments. The files Voss_etal_bkt_preds_csv.zip and Voss_etal_bkt_preds_shp.zip contain the model predictions themselves (see below for details).
Files and variables
File: Voss_BKT_SSN_analysis_final.R
Description: This file contains all R code used to create the results, tables, and figures associated with the submitted manuscript "Climate-driven brook trout invasions in shifting bull trout habitat: an application of spatial-stream-network modeling".
File: Voss_BKT_SSN_CandModelFixedEffectTerms.xlsx
Description: The file Voss_BKT_SSN_CandModelFixedEffectTerms.xlsx contains the model structures for each candidate model created in Voss_BKT_SSN_analysis_final.R. There is no data contained in Voss_BKT_SSN_CandModelFixedEffectTerms.xlsx; it is simply a 'shortcut' I created to avoid repetitively specifying similar models in the R console.
File: Voss_etal_bkt_preds_csv.zip
Description: Voss_etal_bkt_preds_csv.zip contains a CSV file containing habitat-based predictions of nonnative brook trout occurrence for 100,506 stream segments in Idaho. All predictions were computed by a spatial-stream-network (SSN) species distribution model created by Voss et al. 2026 (Ecosphere, in press). The predictions contained in this CSV file are identical to the predictions in Voss_etal_bkt_preds_shp.zip; the CSV format simply allows more straightforward use in R. Because predictions were made regardless of the accessibility of stream segments to brook trout (e.g., segments above fish passage barriers are included), predictions in areas inaccessible to brook trout are indicative of local habitat suitability rather than current occupancy. Stream segments may be classified as 'suitable' or 'unsuitable' for nonnative brook trout (i.e., invadable versus un-invadable) based on an optimal probability threshold of 0.59 (see manuscript for details). Predictions are georeferenced to the midpoint of the stream segments they represent. The table contains six fields defined as follows:
SegID: A unique identifier for each stream segment.
Lat: Latitude of the prediction point (i.e., the midpoint of the stream segment it represents).
Lon: Longitude of the prediction point (i.e., the midpoint of the stream segment it represents).
SegLen_km: Length of the stream segment in river km.
pBKT_bl: Predicted probability of occurrence for the baseline climate scenario (1990-2015).
pBKT_fu: Predicted probability of occurrence for the future climate scenario (2080s).
File: Voss_etal_bkt_preds_shp.zip
Description: Voss_etal_bkt_preds_shp.zip contains a shapefile containing habitat-based predictions of nonnative brook trout occurrence for 100,506 stream segments in Idaho. The predictions contained in this shapefile are identical to the predictions in Voss_etal_bkt_preds_csv.zip; the shapefile format simply allows easier importing for mapping and geospatial analysis. All predictions were computed by a spatial-stream-network (SSN) species distribution model created by Voss et al. 2026 (Ecosphere, in press). Because predictions were made regardless of the accessibility of stream segments to brook trout (e.g., segments above fish passage barriers are included), predictions in areas inaccessible to brook trout are indicative of local habitat suitability rather than current occupancy. Stream segments may be classified as 'suitable' or 'unsuitable' for nonnative brook trout (i.e., invadable versus un-invadable) based on an optimal probability threshold of 0.59 (see manuscript for details). Predictions are georeferenced to the midpoint of the stream segments they represent. The table contains six fields defined as follows:
SegID: A unique identifier for each stream segment.
Lat: Latitude of the prediction point (i.e., the midpoint of the stream segment it represents).
Lon: Longitude of the prediction point (i.e., the midpoint of the stream segment it represents).
SegLen_km: Length of the stream segment in river km.
pBKT_bl: Predicted probability of occurrence for the baseline climate scenario (1990-2015).
pBKT_fu: Predicted probability of occurrence for the future climate scenario (2080s).
Code/software
Voss_BKT_SSN_analysis_final.R contains R code used to create the results, tables, and figures associated with the submitted manuscript "Climate-driven brook trout invasions in shifting bull trout habitat: an application of spatial-stream-network modeling".
Conditioning_RME_metrics_for_MediumRes_NHD_flowlines.R contains R code capable of conditioning Riverscape Metrics Engine (RME; https://data.riverscapes.net) stream habitat metrics for compatibility with NORWEST stream flowline segments. This was done to create several candidate variables for the models presented in the submitted manuscript "Climate-driven brook trout invasions in shifting bull trout habitat: an application of spatial-stream-network modeling".
Access information
Input files listed in Voss_BKT_SSN_analysis_final.R:
- ssn_object.ssn: This file contains proprietary fish survey data and cannot be shared. The fish survey data are the property of the Idaho Department of Fish and Game (https://idfg.idaho.gov/data/request), U.S. Forest Service (https://www.fs.usda.gov/about-agency/foia/contact-service-centers), U.S. Bureau of Reclamation (https://data.usbr.gov/), and Idaho Power Company (https://tools.idahopower.com/forms/ContactUs/Submit). The authors will gladly facilitate third-party data requests to proprietary owners of survey data upon request.
- Voss_BKT_SSN_CandModelFixedEffectTerms.xlsx; This file is available through the Dryad repository.
- BKTPredPts_wBaselinePreds.csv: This file represents an intermediate step in the production of Voss_etal_2026_BrookTroutPredictions_AllScenarios_05-12-26.csv, which is publicly available through the Dryad repository. The intermediate file is fully redundant with Voss_etal_2026_BrookTroutPredictions_AllScenarios_05-12-26.csv.
- NorWeST_AIDPUCG_w_CSBLT1980_IDs.csv: This file is a simple intersection of two publicly available datasets (Bull Trout Cold-Water Habitat Patches for the 1980s–2010s, and NorWeST stream flowline segments) that can be downloaded at https://research.fs.usda.gov/rmrs/products/dataandtools/climate-shield-arcgis-shapefiles and https://research.fs.usda.gov/rmrs/projects/norwest respectively.
- CS1980patches_w_BLT_confirmed.csv: This file contains proprietary fish survey data and cannot be shared. The fish survey data are the property of the Idaho Department of Fish and Game (https://idfg.idaho.gov/data/request), U.S. Forest Service (https://www.fs.usda.gov/about-agency/foia/contact-service-centers), U.S. Bureau of Reclamation (https://data.usbr.gov/), and Idaho Power Company (https://tools.idahopower.com/forms/ContactUs/Submit). The authors will gladly facilitate third-party data requests to proprietary owners of survey data upon request.
- Voss_etal_2026_BrookTroutPredictions_AllScenarios_05-12-26.csv: This file is available through the Dryad repository.
- NorWeST_AIDPUCG_w_CSBLT2080_IDs.csv: This file is a simple intersection of two publicly available datasets (Bull Trout Cold-Water Habitat Patches for the 2080s, and NorWeST stream flowline segments) that can be downloaded at https://research.fs.usda.gov/rmrs/products/dataandtools/climate-shield-arcgis-shapefiles and https://research.fs.usda.gov/rmrs/projects/norwest respectively.
- CS2080patches_paired_w_occupied1980_patches.csv: This file is a simple intersection of two publicly available datasets (Bull Trout Cold-Water Habitat Patches for the 1980s–2010s and Bull Trout Cold-Water Habitat Patches for the 2080s), both of which can be downloaded at https://research.fs.usda.gov/rmrs/products/dataandtools/climate-shield-arcgis-shapefiles.
- Bull Trout Core Areas SSA 2024.shp: This shapefile is the property of the U.S. Fish and Wildlife Service and requests for file sharing should be directed to Daniel_Nolfi@fws.gov.
Input files listed in Conditioning_RME_metrics_for_MediumRes_NHD_flowlines.R:
- rme_MoI_500m.gpkg: The input file containing Riverscape Metrics Engine (RME; https://data.riverscapes.net) prediction points encoded with habitat metrics of interest.