Lichen cover mapping for caribou ranges in interior Alaska and Yukon
Previous research indicates that the effects of climate warming, including shrub expansion and increased fire frequency may lead to declining lichen abundance in arctic tundra and northern alpine areas. Lichens are important forage for caribou ( Rangifer tarandus ), whose populations are declining t...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2020-01-01
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| Series: | Environmental Research Letters |
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| Online Access: | https://doi.org/10.1088/1748-9326/ab6d38 |
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| _version_ | 1839632900418437120 |
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| author | Matthew J Macander Eric C Palm Gerald V Frost Jim D Herriges Peter R Nelson Carl Roland Kelsey L M Russell Mike J Suitor Torsten W Bentzen Kyle Joly Scott J Goetz Mark Hebblewhite |
| author_facet | Matthew J Macander Eric C Palm Gerald V Frost Jim D Herriges Peter R Nelson Carl Roland Kelsey L M Russell Mike J Suitor Torsten W Bentzen Kyle Joly Scott J Goetz Mark Hebblewhite |
| author_sort | Matthew J Macander |
| collection | DOAJ |
| description | Previous research indicates that the effects of climate warming, including shrub expansion and increased fire frequency may lead to declining lichen abundance in arctic tundra and northern alpine areas. Lichens are important forage for caribou ( Rangifer tarandus ), whose populations are declining throughout most of North America. To clarify how lichen cover might affect caribou resource selection, ecologists require better data on the spatial distribution and abundance of lichen. Here, we use a combination of field data and satellite imagery to model lichen cover for a 583 200 km ^2 area that fully encompasses nine caribou ranges in interior Alaska and Yukon. We aggregated data from in situ vegetation plots, aerial survey polygons and unmanned aerial vehicle (UAV) imagery to align with 30 m resolution Landsat pixels. We used these data to train a random forest model with a suite of environmental and spectral predictors to estimate lichen cover. We validated our lichen cover model using reserved training data and existing external datasets, and found that reserved data from aerial survey polygons ( R ^2 = 0.77) and UAV imagery ( R ^2 = 0.71) provided the best fit. We used our lichen cover map to evaluate the influence of estimated lichen cover on caribou resource selection in the Fortymile Herd from 2012 to 2018 during summer and winter. In both seasons, caribou avoided lichen-poor areas (0%–5% lichen cover) and showed stronger selection as lichen cover increased to ∼30%, above which selection leveled off. Our results suggest that terrestrial lichen cover is an important factor influencing caribou resource selection in northern boreal forests across seasons. Our lichen cover map goes beyond existing maps of lichen abundance and distribution because it incorporates extensive field data for model training and validation and estimates lichen cover over a much larger spatial extent. We expect our landscape-scale map will be useful for understanding trends in lichen abundance and distribution, as well as for caribou research, management and conservation. |
| format | Article |
| id | doaj-art-a36bf8a24d414411a16a39f06b0111f7 |
| institution | Matheson Library |
| issn | 1748-9326 |
| language | English |
| publishDate | 2020-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj-art-a36bf8a24d414411a16a39f06b0111f72025-07-11T08:04:19ZengIOP PublishingEnvironmental Research Letters1748-93262020-01-0115505500110.1088/1748-9326/ab6d38Lichen cover mapping for caribou ranges in interior Alaska and YukonMatthew J Macander0https://orcid.org/0000-0003-2808-208XEric C Palm1https://orcid.org/0000-0002-5330-4804Gerald V Frost2https://orcid.org/0000-0002-5134-0334Jim D Herriges3Peter R Nelson4Carl Roland5Kelsey L M Russell6Mike J Suitor7Torsten W Bentzen8Kyle Joly9Scott J Goetz10https://orcid.org/0000-0002-6326-4308Mark Hebblewhite11https://orcid.org/0000-0001-5382-1361ABR, Inc.—Environmental Research & Services, Fairbanks, AK 99708, United States of AmericaW A Franke College of Forestry and Conservation, University of Montana , Missoula, MT 59812, United States of AmericaABR, Inc.—Environmental Research & Services, Fairbanks, AK 99708, United States of AmericaBureau of Land Management, Fairbanks, AK 99709, United States of AmericaUniversity of Maine-Fort Kent , Fort Kent, Maine 04743, United States of AmericaNational Park Service, Fairbanks, AK 99709, United States of AmericaDepartment of Environment, Yukon Government, Whitehorse, YT Y1A 4Y9, CanadaDepartment of Environment, Yukon Government, Dawson City, YT Y0B 1G0, CanadaAlaska Department of Fish and Game, Fairbanks, AK 99701, United States of AmericaNational Park Service, Fairbanks, AK 99709, United States of AmericaSchool of Informatics, Computing, and Cyber Systems, Northern Arizona University , Flagstaff, AZ 86011-5693, United States of AmericaW A Franke College of Forestry and Conservation, University of Montana , Missoula, MT 59812, United States of AmericaPrevious research indicates that the effects of climate warming, including shrub expansion and increased fire frequency may lead to declining lichen abundance in arctic tundra and northern alpine areas. Lichens are important forage for caribou ( Rangifer tarandus ), whose populations are declining throughout most of North America. To clarify how lichen cover might affect caribou resource selection, ecologists require better data on the spatial distribution and abundance of lichen. Here, we use a combination of field data and satellite imagery to model lichen cover for a 583 200 km ^2 area that fully encompasses nine caribou ranges in interior Alaska and Yukon. We aggregated data from in situ vegetation plots, aerial survey polygons and unmanned aerial vehicle (UAV) imagery to align with 30 m resolution Landsat pixels. We used these data to train a random forest model with a suite of environmental and spectral predictors to estimate lichen cover. We validated our lichen cover model using reserved training data and existing external datasets, and found that reserved data from aerial survey polygons ( R ^2 = 0.77) and UAV imagery ( R ^2 = 0.71) provided the best fit. We used our lichen cover map to evaluate the influence of estimated lichen cover on caribou resource selection in the Fortymile Herd from 2012 to 2018 during summer and winter. In both seasons, caribou avoided lichen-poor areas (0%–5% lichen cover) and showed stronger selection as lichen cover increased to ∼30%, above which selection leveled off. Our results suggest that terrestrial lichen cover is an important factor influencing caribou resource selection in northern boreal forests across seasons. Our lichen cover map goes beyond existing maps of lichen abundance and distribution because it incorporates extensive field data for model training and validation and estimates lichen cover over a much larger spatial extent. We expect our landscape-scale map will be useful for understanding trends in lichen abundance and distribution, as well as for caribou research, management and conservation.https://doi.org/10.1088/1748-9326/ab6d38arctic boreal vulnerability experimentcaribouclimate changefirelichenremote sensing |
| spellingShingle | Matthew J Macander Eric C Palm Gerald V Frost Jim D Herriges Peter R Nelson Carl Roland Kelsey L M Russell Mike J Suitor Torsten W Bentzen Kyle Joly Scott J Goetz Mark Hebblewhite Lichen cover mapping for caribou ranges in interior Alaska and Yukon Environmental Research Letters arctic boreal vulnerability experiment caribou climate change fire lichen remote sensing |
| title | Lichen cover mapping for caribou ranges in interior Alaska and Yukon |
| title_full | Lichen cover mapping for caribou ranges in interior Alaska and Yukon |
| title_fullStr | Lichen cover mapping for caribou ranges in interior Alaska and Yukon |
| title_full_unstemmed | Lichen cover mapping for caribou ranges in interior Alaska and Yukon |
| title_short | Lichen cover mapping for caribou ranges in interior Alaska and Yukon |
| title_sort | lichen cover mapping for caribou ranges in interior alaska and yukon |
| topic | arctic boreal vulnerability experiment caribou climate change fire lichen remote sensing |
| url | https://doi.org/10.1088/1748-9326/ab6d38 |
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