

Pine trees, 310, 311 



air pollutants and, 337 



Bristlecone, 61 



Loblolly, 308, 310 



Longleaf, 306 



Shortleaf, 308 

 Piscivores, 227 

 Pitts, Grover C, 390 

 Planktivorous fish, 227, 228 

 Plankton, 53, 231, 340, 344 



see also Phytoplankton; Zooplankton 

 Plant-water relationships, 219-220 

 Plants 



aerobiology and, 343 



antarctic, 313, 314 



aquatic, 236 



arctic, 314 



diseases, 341, Fig. X-8 



food chain, Fig. IX-6 



food production, 216 



growth, 288, 289 



leaves, systems analysis, 289 



spore reproduction, Fig. XI-1 

 Plasma physics, 3, 5, 8 

 Plasmapause, 8 



Plate techtonics, see Global techtonics 

 Pleistocene era, 62, 73, 74 

 Pliocene age, 204 

 Plum Island, Mass., 133, 135 

 Polar bear, 377 

 Polar caps 



absorption, 11, 14 



magnetopause, 7 

 Polar front zone, 84 



precipitation, 165 

 Polar regions 



ecosystems, 313-315 



effect of aerosols, 68 



floating oil, 362 



ice melting possibilities, 119 



information lack on magnetopause over, 7 



ionosphere and, 10 



radio communication over, 11, 14-15, 17 



shipping in, 82 



soil studies, 291 



see also Antarctica; Arctic regions 

 Polar wind: in F region of ionosphere, 10 

 Political considerations 



air pollution control, Fig. X-4, 334 



pesticides, 353 

 Point Barrow, Alaska, 313, 315 

 Pollen 



aerobiology, Fig. X-7 



air pollution, 339, 340, 343, 345-349 



profiles 



climatic change and, 59, 60, 61, 

 72, 73, 74 

 Pollinosis, see Allergens, Airborne 

 Pollution 



programs, 232 



projection, Fig. X-5 



worldwide, 190 

 Pollution, Atmospheric 



abatement by precipitation augmentation, 

 177, 178 



biological, 339-349 



chemical, 319, 320, 321, 327, 329-338, 357 

 pesticides, 354-356 



effect on temperature, 194 

 forecasting of, 101 

 forests, 298 



fire in, 213, 311, 312 

 Great Lakes area, 264, 268 

 hemispheric interchange of air, 188 

 lake eutrophication, 268 

 man-made 



influence on climatic changes, 55, 57, 



65, 66, 68, 69, 71, 72, 115 

 urban effects, 113, 116, 117, 118, 119 

 models 



dispersion, 89, 96 

 weather forecasting, 93 

 natural causes 



influence on climatic changes, 55, 69, 72 

 volcanoes, 21, 55, 56, 68, 71, 72, 329 

 nuclei for precipitation, 192, 193 

 radioactive elements, 33 

 regional controls, 332 

 smog, 385 

 turbulence and, 108 



acoustic monitoring, 112 

 upper atmosphere, 65, 69 

 see also Carbon monoxide 

 Pollution, Chemical 

 estuaries, 248 

 Great Lakes, 264, 265, 268 

 pesticides, 354-356 

 Pollution, Industrial 



atmosphere, 55, 357, 358 

 chemicals 



Great Lakes, 264 

 from petroleum products, 248 

 lake eutrophication, 268 

 Pollution, Noise, 326, 327 

 Pollution, Radioactive, 33, 323, 325 

 Pollution, Soil, see Soils 

 Pollution, Thermal, 34, 199-200, 255, 

 Fig. VIII-12, 322, 337 

 coastal areas, 248 

 fish culture and, 252 

 lakes, 254 



Great Lakes, 263, 264, 266, 268 

 Lake Michigan, 257-260, Fig. VIII-13 

 oceans, 245 

 Pollution, Water 



abatement by precipitation augmentation, 



177 

 antarctic, 241-242 

 coastal areas, Fig. VIII-7 

 enrichment of Great Lakes, 227, 228 

 forest areas, 206-207, 209, 312 

 lakes, 254, 257 

 sea farming and, 251 

 world ocean, 79, 82, 83, 244, 245, 



Fig. VIII-8 

 see also Pollution, Thermal; Sewage 

 Polygons: arctic tundra, Fig. IX-15 

 Polygyny: population structure and, 378 

 Polymorphism, 373, 374 

 Pompano, 250 

 Pompeii, 40 



Pond culture of fish, 217 

 Population density 



arable land in relation to, Fig. VII-8 

 cause of pollution, 330, 350 

 effect on forest and, 293 



control of numbei 



environmental des 



modification of earth'-. 



soil fertility and, 40, 45 



water use factors, 198 

 Porometer, 201 

 Porpoises, see Dolphins 

 Port Louis, Mauritius Isl., 135 

 Portales, Texas, 204 

 Potash, see Potassium 

 Potassium, 32, 215, 300 



eutrophication in Great Lakes, 268 

 Power-generating plants 



thermal water discharges, 199-200, 249, 

 254, 257, 325, 337 

 benefits for aqua farming, 252 

 Great Lakes, 263, 268 

 influence on Lake Michigan, 

 Fig. VIII-13 

 Prairies 



solar radiation in, 55 



climatic change, 73 

 Precambrian rocks, 30 

 Precession of the earth, 54 

 Precipitation 



atmosphere-ocean system, 67, 360 



biological particulates, Fig. X-6, 349 



climatic records, 51, 58 



dust removal by, 358 



fluctuations, 57 



forecasting, 100, 102 



forest land, 205 



in forest ecosystems, 294 



indicated by tree rings, Fig. Ill— 5 



models, 89, 95 



modification, 169-179, Fig. VI-2 



nucleation centers, 329 



urbanization and, 113, 117, 118 

 pollution in, 119, 337 



water cycle, 198, 200, Fig. VII-2 

 lake eutrophication, 268 



world-wide, 165, Fig. VI-1 



see also Rainfall; Snow 

 Precipitation stations 



National Weather Service, 197 

 Predators 



balance of nature, 280 



control of, 303 



in forest ecosystem, 292, 302 



modeling, 282 



see also Isle Royale ecosystem 

 Predictions 



air turbulence, 111 



change in shallow-water communities, 

 230-231 



climatic changes, 59, 61 



droughts, 165-168, 172, 221 



earthquakes, 35, 36, 38 



forest stream temperature, 206 



injury to ecological systems, 340, 342 



lead concentrations in ocean, 360 



long-range effects on biosphere, 280 



processes in forest ecosystems, 292-293 



responses of ecosystems to changes, 300 



responses within ecosystems, 289 



sea-air rhythms, 78, 79, 80, 81, 89 



solar activities, 5, 6, 11, 13, 16-17 



volcanic eruptions, 43-45 



415 



