Index 



Page numbers in bold face type indicate illustrative material. 



Abelia, 142 



affected by length of day, 142 

 Abies a?nabilis, 276 



balsamea, 63, 240, 241, 243, 245, 248 



concolor, 70, 264, 272, 274 



fraseri, 244, 245 



grandis, 277, 279 



lasiocarpa, 244, 261, 276 



magnified, 70, 270, 271, 274 



nobilis, 276 

 Abstract communities, 69 

 Abundance, 56-58 

 Abundance scale, 58 

 Acer glabrwn, 70 



rubrum, 63, 249 



saccharum, 63, 246, 247, 248, 249, 

 253, 255 

 Acid and alkaline soils, 178-179 



see Alkalinity, pH 

 Adaptation and survival, 30 

 Adaptations, aeration 



aquatic plants, 175-176, 217-218 



emergent plants, 175-176 



lacunar tissue, 175-176 



pneumatophores, 176 



submerged leaves, 176 

 Ad eno stoma jasciculatum, 139 

 Aeration, 174 



and leaf structure, 138-139 



decreases with depth (soil), 174 



toxicity, 182 

 Aes cuius califomica, 275 



octandra, 248, 249 

 Agave, 290 

 Agricultural indicators, 352-355 



crop centers and natural vegeta- 

 tion, 352 



land evaluation, 355 



land use, 352-353-354 

 Agriculture, 326-337 



crop ecology, 326-327 



land management, 329-332-333 



land use, 328-329 



pasture problems, 333-336 



pests, 336-337 

 Agropyron, 268 



repens, 292 



smithii, 297 



spicatum, 297 

 Agrostis alba, 292 

 Ao horizon, 154 

 Air capacity of soil, 175 

 Alkalinity, of soil, 178-179 



calciphiles, 183 



causes, 183 



pH, 178-179 



plant relationships, 183 

 Alluvial soils, 149-150 



texture of, 150 

 Alnus incana, 242 

 Alpine soil, 145 

 Alpine tundra, 236, 239-240 



location, altitudes, 239 

 Alpine vegetation, 145, 236 



Krumviholz, 145 

 Altitudinal zones, 124, 133 



in Utah, 125 

 Amelanchier spp., 269 

 Ammonification, 196-197 

 Andromeda polifolia, 239, 242 

 Andropogon, 218, 219, 221 



furcatus, 292, 295 



littoral is, 51, 52 



saccharoides, 293 



scoparius, 292, 295 



tener, 293 



ternarius, 293 

 Anemometers, cup and Biram, 99 

 Animals • 



as dependents, 26 



as factors 



dissemination, 198-199 

 grazing and browsing, 201-202 

 in soil, 200 

 man, 202-210 



371 



