Mapping tree cover expansion in Montana, U.S.A. rangelands using high‐resolution historical aerial imagery
Abstract Worldwide, trees are colonizing rangelands with high conservation value. The introduction of trees into grasslands and shrublands causes large‐scale changes in ecosystem structure and function, which have cascading impacts on ecosystem services, biodiversity, and agricultural economies. Sat...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2024-02-01
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| Series: | Remote Sensing in Ecology and Conservation |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/rse2.357 |
| _version_ | 1797294390904881152 |
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| author | Scott L. Morford Brady W. Allred Eric R. Jensen Jeremy D. Maestas Kristopher R. Mueller Catherine L. Pacholski Joseph T. Smith Jason D. Tack Kyle N. Tackett David E. Naugle |
| author_facet | Scott L. Morford Brady W. Allred Eric R. Jensen Jeremy D. Maestas Kristopher R. Mueller Catherine L. Pacholski Joseph T. Smith Jason D. Tack Kyle N. Tackett David E. Naugle |
| author_sort | Scott L. Morford |
| collection | DOAJ |
| description | Abstract Worldwide, trees are colonizing rangelands with high conservation value. The introduction of trees into grasslands and shrublands causes large‐scale changes in ecosystem structure and function, which have cascading impacts on ecosystem services, biodiversity, and agricultural economies. Satellites are increasingly being used to track tree cover at continental to global scales, but these methods can only provide reliable estimates of change over recent decades. Given the slow pace of tree cover expansion, remote sensing techniques that can extend this historical record provide critical insights into the magnitude of environmental change. Here, we estimate conifer expansion in rangelands of the northern Great Plains, United States, North America, using historical aerial imagery from the mid‐20th century and modern aerial imagery. We analyzed 19.3 million hectares of rangelands in Montana, USA, using a convolutional neural network (U‐Net architecture) and cloud computing to detect tree features and tree cover change. Our bias‐corrected results estimate 3.0 ± 0.2 million hectares of conifer tree cover expansion in Montana rangelands, which accounts for 15.4% of the total study area. Overall accuracy was >91%, but the producer's accuracy was lower than the user's accuracy (0.60 vs. 0.88) for areas of tree cover expansion. Nonetheless, the omission errors were not spatially clustered, suggesting that the method is reliable for identifying the regions of Montana where substantial tree expansion has occurred. Using the model results in conjunction with historical and modern imagery allows for effective communication of the scale of tree expansion while overcoming the recency effect caused by shifting environmental baselines. |
| first_indexed | 2024-03-07T21:30:33Z |
| format | Article |
| id | doaj.art-3f9e78b038a54ebaae7e637013a59fee |
| institution | Directory Open Access Journal |
| issn | 2056-3485 |
| language | English |
| last_indexed | 2024-03-07T21:30:33Z |
| publishDate | 2024-02-01 |
| publisher | Wiley |
| record_format | Article |
| series | Remote Sensing in Ecology and Conservation |
| spelling | doaj.art-3f9e78b038a54ebaae7e637013a59fee2024-02-26T17:17:13ZengWileyRemote Sensing in Ecology and Conservation2056-34852024-02-011019110510.1002/rse2.357Mapping tree cover expansion in Montana, U.S.A. rangelands using high‐resolution historical aerial imageryScott L. Morford0Brady W. Allred1Eric R. Jensen2Jeremy D. Maestas3Kristopher R. Mueller4Catherine L. Pacholski5Joseph T. Smith6Jason D. Tack7Kyle N. Tackett8David E. Naugle9Numerical Terradynamic Simulation Group University of Montana Missoula Montana 59812 USAUniversity of Montana, W. A. Franke College of Forestry and Conservation Missoula Montana 59812 USANumerical Terradynamic Simulation Group University of Montana Missoula Montana 59812 USAUnited States Department of Agriculture Natural Resources Conservation Service Portland Oregon 97232 USANumerical Terradynamic Simulation Group University of Montana Missoula Montana 59812 USAUnited States Department of Agriculture Natural Resources Conservation Service Bozeman Montana 59715 USANumerical Terradynamic Simulation Group University of Montana Missoula Montana 59812 USAUnited States Fish and Wildlife Service, Habitat and Population Evaluation Team Missoula Montana 59812 USAUnited States Department of Agriculture Natural Resources Conservation Service Bozeman Montana 59715 USAUniversity of Montana, W. A. Franke College of Forestry and Conservation Missoula Montana 59812 USAAbstract Worldwide, trees are colonizing rangelands with high conservation value. The introduction of trees into grasslands and shrublands causes large‐scale changes in ecosystem structure and function, which have cascading impacts on ecosystem services, biodiversity, and agricultural economies. Satellites are increasingly being used to track tree cover at continental to global scales, but these methods can only provide reliable estimates of change over recent decades. Given the slow pace of tree cover expansion, remote sensing techniques that can extend this historical record provide critical insights into the magnitude of environmental change. Here, we estimate conifer expansion in rangelands of the northern Great Plains, United States, North America, using historical aerial imagery from the mid‐20th century and modern aerial imagery. We analyzed 19.3 million hectares of rangelands in Montana, USA, using a convolutional neural network (U‐Net architecture) and cloud computing to detect tree features and tree cover change. Our bias‐corrected results estimate 3.0 ± 0.2 million hectares of conifer tree cover expansion in Montana rangelands, which accounts for 15.4% of the total study area. Overall accuracy was >91%, but the producer's accuracy was lower than the user's accuracy (0.60 vs. 0.88) for areas of tree cover expansion. Nonetheless, the omission errors were not spatially clustered, suggesting that the method is reliable for identifying the regions of Montana where substantial tree expansion has occurred. Using the model results in conjunction with historical and modern imagery allows for effective communication of the scale of tree expansion while overcoming the recency effect caused by shifting environmental baselines.https://doi.org/10.1002/rse2.357Afforestationagricultural land useglobal changegrasslandrangeland conservationWoody encroachment |
| spellingShingle | Scott L. Morford Brady W. Allred Eric R. Jensen Jeremy D. Maestas Kristopher R. Mueller Catherine L. Pacholski Joseph T. Smith Jason D. Tack Kyle N. Tackett David E. Naugle Mapping tree cover expansion in Montana, U.S.A. rangelands using high‐resolution historical aerial imagery Remote Sensing in Ecology and Conservation Afforestation agricultural land use global change grassland rangeland conservation Woody encroachment |
| title | Mapping tree cover expansion in Montana, U.S.A. rangelands using high‐resolution historical aerial imagery |
| title_full | Mapping tree cover expansion in Montana, U.S.A. rangelands using high‐resolution historical aerial imagery |
| title_fullStr | Mapping tree cover expansion in Montana, U.S.A. rangelands using high‐resolution historical aerial imagery |
| title_full_unstemmed | Mapping tree cover expansion in Montana, U.S.A. rangelands using high‐resolution historical aerial imagery |
| title_short | Mapping tree cover expansion in Montana, U.S.A. rangelands using high‐resolution historical aerial imagery |
| title_sort | mapping tree cover expansion in montana u s a rangelands using high resolution historical aerial imagery |
| topic | Afforestation agricultural land use global change grassland rangeland conservation Woody encroachment |
| url | https://doi.org/10.1002/rse2.357 |
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