Map Production Methods
Methods
Partners in Flight Vegetation Maps
The maps presented at this site were created during 1998-1999 at the Center for Advanced Spatial Technologies at the University of Arkansas. Dates of imagery used in land cover databases are given for each below and in the metadata for each dataset. Metadata may be accessed here. These vegetation cover maps show estimates of habitat coverages based on analysis of Advanced Very High Resolution Radiometer (AVHRR) satellite imagery at a 1 square kilometer (sq km) resolution. Criteria for assigning a particular cover type to a given 1 sq km pixel vary for each database and are specified in the metadata. The nationwide scale of these databases and the resolution at which land cover categories are presented permit the creation of maps for the entire suite of Partners in Flight physiographic areas that are consistent in scale, habitat type designations, and methodology. These maps will be most useful for 1) delineating the locations of the largest remaining areas of contiguous vegetation of specific types on which to focus intense conservation efforts and 2) for showing smaller, adjacent areas of particular valued habitats where management efforts might be implemented to restore continuity and create larger patches. Due to the limitation of the resolution of the baseline data, habitat coverages are estimates and do not purport to reflect coverage of vegetation types at a finer scale than 1 sq km. The 1 sq km resolution may show continuity in a vegetation cover category where patches are, in reality, more dissected than they appear. During the time since the imagery was produced, additional habitat alterations have occurred in some areas, further changing and fragmenting the coverages shown in these maps.
Map Production Methods
A raster map of each physiographic area (PA) was created from a vector digital line graph in the Geographic Resources Analysis Support System (GRASS). A total area was then calculated for the PA. A mask was created from the raster layer which represented the entire PA. That mask was used to create the orientation map showing the PA among surrounding states. Next a mask of each PA was made, omitting urbanized areas. To create the forest type map, the USFS FIA (1991) data were displayed through the PA mask from which urban areas were removed. A tabular report was generated showing all forest types in the PA and areas and percent of total taken by each. The resulting forest cover map was then segmented to create individual maps of each forest type.
A new mask was made from the "nonforest" cover type layer from the USFS data. Through that mask was displayed the USGS land-use-land-cover (LULC, 1990) database. The resulting map is the color nonforest cover type map in each PA mapset. A table was generated to show areas of all cover types included in this map. The "nonforest" map was then segmented to create separate maps for each habitat type. The USGS Landcover dataset has 159 habitat categories; many are very similar combinations of cover types, such as "corn, soybeans, alfalfa, flax, wheat" and "corn, soybeans, pasture, woodlands". Some separate categories are identical; for example, there are 11 numerically different categories, all described as "irrigated agriculture" (see complete category in Appendix 1). By combining similar habitat types on the basis of the first listed cover type, a modified data set with 29 categories was created (Appendix 2). The recategorized data are used in the mapsets.
The table created from the "nonforest" map often shows some forest coverage in the "nonforest" area. In all Partners in Flight regions except the Western Region, each such forest category was reclassed to a nonforest habitat type. The USGS category descriptions normally include several different cover types in order of occurrence in the cell. In the reclassification scheme employed here, the first occurring nonforest habitat type is chosen for the category descriptor. For example, if a landcover type was originally described as "oak, bluestem grassland", that group of cells was reclassed as "bluestem grassland" and combined in the map and table with any other bluestem occurring in the area. In the Western Region PAs all additional forest types shown in the USGS data in the "nonforest" area were retained. Individual maps of each forest type in Western Region maps include both USFS FIA coverage, plus any additional coverage from the USGS data in the "nonforest" area.
Several physiographic areas overlap into Canada. Canadian landcover data were taken from the landcover database produced by the Canada Centre for Remote Sensing (CCRS, 1995) and were used in the color maps of Canadian vegetation created for this project. Black-and-white maps of individual cover types were also created. The categorization scheme followed by the CCRS is somewhat different from that seen in the US databases; therefore, Canadian vegetation types are listed separately on maps and summary tables.
A database showing federal, state, and some private land ownership was acquired from the Remote Sensing Research Unit in the Department of Geography at the University of California, Santa Barbara (UCSB, 1997). This database was displayed through the PA mask (including urban areas) to create the color map of managed lands.
The summary table provided for each PA at the web site incorporates coverages of all forest and nonforest cover types discussed above for that physiographic area.
Road data were taken from a US DOT Bureau of Transportation Statistics (BTS) database.
Appendix 1. Original habitat category designations for USGS LULC vegetation cover database.
1. Spring wheat
2. Soybeans, corn, cotton
3. Small grains, mixed row crops
4. Small grains
5. Small grains, mixed row crops
6. Mixed row crops, small grains
7. Mixed crops
8. Soybeans, cotton, rice, corn
9. Winter wheat
10. Soybeans, cotton, rice, corn
11. Corn, soybeans
12. Small grains, mixed row crops, pasture
13. Small grains, mixed row crops, pasture
14. Mixed crops
15. Soybeans, cotton, corn
16. Corn, soybeans, alfalfa, flax, wheat
17. Corn, soybeans
18. Mixed croplands, pasture, and woodlands
19. Soybeans, corn, cotton, vegetable crops
20. Corn, soybeans, pasture
21. Corn, soybeans, loblolly pine
22. Irrigated agriculture
23. Irrigated agriculture
24. Irrigated agriculture
25. Irrigated agriculture
26. Irrigated agriculture
27. Irrigated agriculture
28. Irrigated agriculture
29. Irrigated agriculture
30. Irrigated agriculture
31. Irrigated agriculture
32. Irrigated agriculture
33. Sorghum, small grains, irrigated agriculture
34. Irrigated agriculture, mixed row crops
35. Bluestem, grama, wheatgrass, small grains
36. Grama, buffalograss, wheat, sorghum
37. Small grains, sorghum, blue grama
38. Wheatgrass, needleandthread, wheat, peas, lentils
39. Bluestem, wheatgrass, wheat, sorghum
40, riparian woods, irrigated agriculture, blue grama
41. Soybeans, cotton, rice, corn, oak, tupelo
42. Corn, soybeans, sorghum, irrigated agriculture, m ixed woodlots
43. Mixed pine, oak, soybeans, corn
44. Pasture, small grains, douglas fir, oak
45. Soybeans, corn, peanuts, cotton, oak, pine
46. Maple, birch, beech, corn, soybeans, pasture
47. Oak, hickory, pine, soybeans, corn, pasture
48. Citrus, pasture, slash pine, longleaf pine
49. Loblolly pine, slash pine, soybeans, corn, peanuts, cotton
50. Pione, oak, soybeans, corn, pasture
51. Pasture, hay, corn, soybeans, oak, hickory
52. Forage crops, hay, woodlots
53. Oak, pine, soybeans, corn, cotton, peanuts
54. Soybeans, cotton, rice, corn, oak, pine
55. Wheatgrass, needlegrass, needleandthread
56. Wheatgrass, needlegrass, needleandthread
57. Bluestem, blue grama
58. Blue grama, wheatgrass, buffalograss
59. Wheatgrass, Blue grama, needleandthread
60. Wheatgrass, fescue, big sage
61. Wheatgrass, Blue grama, needleandthread, big sage
62. Annual grasses, manzanita, oak
63. Wheatgrass, needlegrass
64. Wheatgrass, needlegrass, needleandthread
65. Bluestem, iniangrass, switchgrass
66. Bur sage, saltbush, greasewood, shadscale
67. Greasewood, sage
68. Creosote, mesquite, saltbush, sand sage
69. Creosote, saltbush, sand sage
70. Dropseen sand sage, creosote
71. Saltbush, greasewood, big sage
72. Greasewood, sage, rabbitbrush, needlegrass
73. Sand sage, creosote, ricegrass, blue grama, dropseed
74. Big sage, rabbitbrush, wheatgrass, fescue
75. Greasewood, sage, wheatgrass, needleandthread
76. Sand sage, blue grama, wheatgrass, buffalograss
77. Creosote, sand sage, grama, wheatgrass
78. Big sage, rabbitbrush, wheatgrass, fescue
79. Sand sage, creosote, dropseed, blue grama
80. Blue grama, buffalograss, big sage, saltbush
81. Sand sage, oak. Blue grama, buffalograss
82. Grama, buffalograss, wheatgrass, creosote, mesquite
83. Grama, buffalograss, wheatgrass, creosote, mesquite
84. Annual grasses, manzanita, oak, pine
85. Annual grasses, manzanita, oak, pinyon pine, juniper
86. Bluestem, sand sage, blue grama, oak, juniper
87. Oak, juniper, bluestem, indiangrass, switchgrass
88. Oak, bluestem, indiangrass, mesquite, juniper
89. Oak, bluestem, indiangrass, switchgrass, juniper
90. Maple, birch, white pine, red pine
91. Oak, maple, ash, pasture
92. Maple, birch, beech
93. Beech, birch, maple, oak, pasture
94. Oak, hickory, mixed cropland
95. Oak, hickory, poplar, beech, walnut
96. Aspen, mountain shrubs, grasses
97. Aspen, mountain shrubs
98. Loblolly pine, longleaf pine, slash pine, shortleaf pine
99. Fir, spruce
100. Doublas fir, pacific silver fir, western hemlock
101. Western white pine, ponderosa pine, doublas fir, lodgepole pine
102. Lodgepole pine, ponderosa pine, western white pine, fir, spruce
103. Lodgepole pine, ponderosa pine, western white pine
104. Western white pine, ponderosa pine, lodgepole pine, douglas fir
105. Lodgepole pine, ponderosa pine, douglas fir
106. Ponderosa pine, lodgepole pine, western white pine, juniper
107. Lodgepole pine, ponderosa pine, western white pine
108. Ponderosa pine, pinyon pine, juniper, oak
109. Ponderosa pine, lodgepole pine
110. Douglas fir, pacific silver dir, western hemlock
111. Ponderosa pine, lodgepole pine, juniper
112. Douglas fir, sitka spruce, western hemlock
113. Lodgepole pine, ponderosa pine, western white pine
114. Ponderosa pine, pinyon pine, douglas fir, juniper, aspen
115. Ponderosa pine, lodgepole pine, douglas fir, oak
116. Ponderosa pine, lodgepole pine, western white pine, douglas fir
117. Lodgepole pine, ponderosa pine, western white pine, douglas fir, aspen
118. Ponderosa pine, douglas fir
119. Douglas fir, ponderosa pine, sugar pine, oak
120. Ponderosa pine, douglas fir, oak
121. Ponderosa pine, sugar pine, douglas fir, oak
122. Douglas fir, western hemlock, western redcedar, sitka spruce
123. Western hemlock, western redcedar, douglas fir, sitka spruce, pasture
124. Ponderosa pine, sugar pine, douglas fir, redwood, oak
125. Ponderosa pine, western hemlock, redwood, western redcedar, douglas fir, oak
126. Grasses, ponderosa pine, lodgepole pine
127. Sage, annual grasses, oak, pine
128. Ponderosa pine, lodgepole pine, wheatgrass, sage
129. Ponderosa pine, pinyon pine, juniper
130. Pinyon pine, juniper, grasses, ponderosa pine
131. Ponderosa pine, western white pine, grasses
132. Pinyon pine, juniper, grasses, ponderosa pine, grasses, sage
133. Maple, beech, birch, jack pine, red pine
134. Maple, birch, beech, spruce, fir
135. Spruce, pine, wetlands, northern hardwoods
136. Oak, maple, ash, beech, birch, jack pine, red pine
137. Beech, birch, maple, spruce, fir, hemlock
138. Slash pine, longleaf pine, oak, palm, mangrove, wetlands
139. Loblolly pine, slash pine, oak, gum, soybeans, corn, cotton
140. Loblolly pine, longleaf/shortleaf pine, slash pine, oak, gum, cypress
141. Loblolly pine, slash pine, shortleaf pine, oak, gum, poplar
142. Lodgepole pine, douglas fir, aspen, mountain shrubs
143. Lodgepole pine, western white pine, ponderosa pine, western white pine, aspen, mountain shrubs
144. Lodgepole pine, western white pine, ponderosa pine, western white pine, aspen, mountain shrubs
145. Lodgepole pine, western white pine, ponderosa pine, western white pine, aspen, mountain shrubs
146. Lodgepole pine, douglas fir, aspen
147. Ponderosa pine, lodgepole pine, aspen
148. Ponderosa pine, lodgepole pine, aspen
149. Water
150. Fresh/salt water marsh
151. Fresh/salt water marsh
152. Fresh/salt water marsh
153. Fresh/salt water marsh, baldcypress, mangrove, oak, gum
154. Fresh/salt water marsh, oak, gum, cypress
155. Barren or sparsely vegetated
156. Lodgepole pine, douglas fir, aspen, alpine tundra
157. Alpine tundra
158. Alpine tundra
159. Alpine tundra
Appendix 2. New categories used in "nonforest" area cover type habitat classification. New categories are derived from, and incorporate, one or more cover categories from the original USGS Landcover database shown in Appendix 1.
|
Combined categories in new dataset |
Categories from original USGS database |
|
|
|
|
1. Wheat, small grains |
1-5, 7, 9, 12-14, 33, 37 |
|
2. Corn, soybeans |
6, 8, 10-11, 15-17, 19-21, 41-42, 45, 54 |
|
3. Irrigated agriculture |
22-32, 34 |
|
4. Bluestem grassland |
35, 39, 57, 65, 86 |
|
5. Grama grassland |
36, 58, 80, 82-83 |
|
6. Wheatgrass grassland |
38, 55-56, 59-61, 63-64 |
|
7. Riparian woods |
40 |
|
8. Mixed oak-pine forest |
43, 50, 53 |
|
9. Pasture, hay, mixed crops |
18, 44, 48, 51, 52 |
|
10. Maple, birch, beech forest |
46, 90, 92, 93, 133, 134, 137 |
|
11. Oak-hickory forest |
47, 94-95 |
|
12. Open oak-bluestem woodland |
87-89 |
|
13. Loblolly-slash pine forest |
49, 98, 139 |
|
14. Loblolly-shortleaf pine |
140-141 |
|
15. Annual grasses, manzanita, oak |
62, 84-85 |
|
16. Sagebrush |
66, 73-74, 76, 78-79, 81, 127 |
|
17. Geasewood brushland |
67, 71, 72, 75 |
|
18. Creosote brushland |
68-70, 77 |
|
19. Oak-maple |
91, 136 |
|
20. Longleaf-slash pine forest |
138 |
|
21. Aspen forest |
96-97 |
|
22. Fir-spruce forest |
99-100, 110, 112, 119, 122-123, 135 |
|
23. Ponderosa pine forest |
101, 104, 106, 108-109, 111, 114-116, 118, 120-121, 124-126, 129, 131, 147-148 |
|
24. Lodgepole pine forest |
102-103, 105, 107, 113, 117, 142-146, 156 |
|
25. Pinyon pine, juniper forest |
130, 132 |
|
26. Water |
149 |
|
27. Fresh/salt water marsh |
150-154 |
|
28. Barren, sparse vegetation |
155 |
|
29. Alpine tundra |
157-159 |
Center for Advanced Spatial Technologies
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