| Abstract: | Canopy gaps are important structural components of forested habitats for many wildlife species. Recent improvements in the spatial accuracy of geographic information system tools facilitate accurate mapping of small canopy features such as gaps. We compared canopy-gap maps generated using ground survey methods with those derived from air-photo interpretation. We found that maps created from high-resolution air photos were more accurate than those created from ground surveys. Errors of omission were 25.6% for the ground-survey method and 4.7% for the air-photo method. One variable of inter est in songbird research is the distance from nests to gap edges. Distances from real and simulated nests to gap edges were longer using the ground-survey maps versus the air-photo maps, indicating that gap omission could potentially bias the assessment of spatial relationships. If research or management goals require location and size of canopy gaps and specific information about vegetation structure, we recommend a 2-fold approach. First, canopy gaps can be located and the perimeters defined using 1:15,000-scale or larger aerial photographs and the methods we describe. Mapped gaps can then be field-surveyed to obtain detailed vegetation data. |
| Genre: | Article |
| ProdID: | 1003012 |
| Citation Author: | Fox, T. J.; Knutson, M. G.; Hines, R. K. |
| Citation Contributing Office: | Upper Midwest Environmental Sciences Center |
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| Citation End Page: | 889 |
| Citation Issue: | 4 |
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| Citation Language: | English |
| Citation Larger Work Title: | Wildlife Society Bulletin |
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| Citation Number Of Pages: | 8 |
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| Citation Phsyical Description: | pp. 882-889 |
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| Citation Publisher: | U.S. Fish and Wildlife Service |
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| Citation Search Results Text: | Mapping forest canopy gaps using air-photo interpretation and ground surveys; 2000; Article; Journal; Wildlife Society Bulletin; Fox, T. J.; Knutson, M. G.; Hines, R. K. |
| Citation Start Page: | 882 |
| Citation Volume: | 28 |
| Citation Year: | 2000 |
| Type: | citation/reference |
| Text: | Mapping forest canopy gaps using air-photo interpretation and ground surveys; 2000; Article; Journal; Wildlife Society Bulletin; Fox, T. J.; Knutson, M. G.; Hines, R. K. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Sat, 1 Jan 2000 00:00 -0600 |
| Publisher: | U.S. Fish and Wildlife Service |
