This Port-Orford-cedar mapping effort was initiated by Frank Betlejewski, Interregional Port-Orford-cedar Program Manager, USDA Forest Service; source aerial photos (Biscuit Fire only) utilized in this effort are stored at the Southwest Oregon Forest Insect and Disease Service Center; other aeriel photography is from the following sources: the Coos Bay District office, Bureau of Land Management, the Gold Beach and Wild Rivers Ranger Districts (Rogue River - Siskiyou National Forest), the Klamath National Forest, the Shasta-Trinity National Forest, the Siuslaw National Forest, and the Six Rivers National Forest. The enterprise geospatial dataset resides on each of the above mentioned administrative units, the Regional Offices for Forest Service Region 5 (Vallejo, California) and Region 6 (Portland, Oregon). The source of the data: - Varies by each polygon (specified in "Source" column of the Polygon Attribute Table) -1:12,000 scale true color aerial photo transparencies taken in 1986/87 (A/1986 or 1987), 1997, 2001, or 2002. (Region 5 and Region 6). -1:12,000 scale true color aerial photo prints taken in 1997 (P/1997) - Field verification or other field derived information (F/2007) -1992 Interregional Mapping Data Base of POC and its root disease. -Existing stand examinations (exams must be indexed on a map to be useful).(T/date of exam) -Stocking surveys for each harvest unit.(T/date of exam) -USFS (Oregon) roadside mapping of POC and its disease. (F/date if known) -"Identification Of Port-Orford Cedar And Associated Species On Large Scale Color and Color-IR Aerial Photos" by Bill Ciesla (former Director R-6 Forest Pest Management) and Mike Hoppus of the USFS Nationwide Forestry Application Program. -Serpentine soil maps from the USDA Natural Resources Conservation Service -2005 orthophoto maps (Oregon) with 1992 mapping data overlayed Region 5 only: Due to the greater detail in the original mapping (site visits, seral stage classification, size class classification, and plant association classification), the inventory updates were derived from aerial photo interpretation only. Region 6 only, Gold Beach and Wild Rivers Ranger Districts, outside of the Biscuit Fire perimeter, Rogue River - Siskiyou National Forest: Important Factors Affecting The Mapping of Live Port Orford Cedar: 1A. On the Gold Beach RD BLM 2002 aerial photo transparencies (APT's) were available in all of 1/4 quads 16d, 17c, 17d, 18c, 28a, 28b, 29b, most of 18a, and about ½ of 17b, 28c, and 29d. APT's are important because their color and detail resolution is much improved over normal print aerial photos. This improves the accuracy of live POC identification. 1B. On the Wild Rivers RD four different sources of aerial photo transparencies (APT's) were used. APT's from the 1986/87 set, BLM 1996 set, BLM 2001 set and the 2002 Biscuit fire set. Of the four sets the 2002 set was the best and the 2001 next in accuracy. The 1996 and 1986/87 set resulted in significantly lower accuracy mainly because the distinctive color of the POC was not as readily apparent. The Source column indicates which photo set was used for each polygon. 1C. As listed below, the minimum mapping size standards for live POC polygons was 2.5 acres along streams and 5 acres in upland situations. 1D. Much effort was made to assess live POC distribution within 300 feet or more along roads. Since this species regenerates particularly well on disturbed surfaces, roadsides commonly have a much greater concentration of POC than is present on non disturbed or natural forest land. For this reason roadside POC that was judged to be road disturbance associated was disregarded in this mapping. 1E. The dead trees and their generally distinctive pattern of POC root disease can be reliably (with some errors) detected on print aerial photos. 1F. The above factors, in addition to not using wide road and stream side buffers, cause this mapping to be distinctively different from that done in 1992. 1G. In the remarks many polygons will have IC & POC. This indicates that incense cedar is likely to be present in the polygon along with Port-Orford cedar. The interpreter was unable to accurately distinguish between the two since their photo characteristics are very similar. 1H. In the Illinois Valley area root disease mapping was done under a previous BLM contract. When available, polygons, root disease only, were printed on the base 1/4 quads for this mapping effort. To avoid "sliver" polygons, these root disease polygons were often expanded to enclose adjacent live POC. 2. A) Importantly, this project did not rescan the land base for live POC or root disease not identified in the 1992 Data Base or other documented delineations. The focus was to review and evaluate the accuracy of the existing mapping and make appropriate changes. If additional areas of live POC or root disease were detected in the course of this work they were mapped and documented. 2. B) Limitations to mapping accuracy: 1) For identification of live POC using aerial photo transparencies (APT's), the distinctive color of the species is most apparent to the photo interpreter when photos are taken either earlier or later in the day or year. For example, the Biscuit fire photos were taken on September 24th and the POC color was easily detected. For this reason the identification of live POC on the APT's other than the Biscuit photos is more difficult and the photo interpretation more prone to errors of commission and omission. An exception to this rule is serpentine soil areas and some other areas where the color of live POC is readily apparent. To partially compensate for this situation photo interpretation involved frequent use of the 6 power binoculars, reliance on notes from field reviews and the interpreter's knowledge of site conditions where POC is most likely to occur. 2) Locations where incense cedar (IC) and Port-Orford cedar (POC) are present: On positive transparencies the color and crown appearance of these two species are similar. To separate them the interpreter had to look for a slight brownish color to the yellow green of the IC and the fact that this species can grow on drier sites than the POC. In these situations (both on the Gold Beach and Wild Rivers R.D.'s) the risk of errors of omission and commission increases. In many situations, including riparian areas, these species are intermixed. The interpreter has indicated the above situations with the term IC & POC in the remarks column. In most situations the interpreter made a separation between areas with likely IC and not included that with live POC mapping. The user should be aware that these decisions increase the risk of missing POC (errors of omission). 3) In many situations live POC is adjacent to root disease polygons. If this POC met the 2.5 and 5 acre minimum polygon size requirements it was mapped. Otherwise it was either included with the root disease polygon or left out. This is a systemic source of error for live POC mapping.