Index 



529 



Moisture, in soil, 111 



influence on growth and distribution, 

 121-128 

 Mollusks, nutrition in, 293 



production of, 502 

 Monophagous animals, 294 

 Mortality, 5-10, 333-334, 459 

 Mosquito larvae, feeding of, 62-63 

 Mud-bottom community, 409, 443 

 Muskeg, 183, 431 

 Muskox, 329 

 Mussels, 64, 390, 443 

 Mutualism, with continuous contact, 

 364-370 



without continuous contact, 370-374 

 Mycorrhizae, 366-367 



Nannoplankton, 478 



see also Plankton 

 Natality, 333-334 

 Nekton, 36 

 Neritic province, 30 

 Neuston, 62 

 Niche, 468-469 

 Nitrates, in lakes, 288 



in plant growth, 280-283 



in oceans, 288-289, 306-307 



in soil, 284 

 Nitrification, 298-299 

 Nitrogen, availabihty of, 80, 280 



release of, 299-301 



requirement of plants, 280 

 Nitrogen cycle, 299 

 Nitrogen fixation, 299 

 Nomadism, 357 

 Non-conservative factors, 21 

 Nutrients, availability for plants, 284 



in fresh water, 287 



in oceans, 287-289, 475-476 



in soil, 80, 284-286 



influence on animals, 292-297 



limitation by, 283-292 



regeneration of, 304-308 



requirements of animals, 292 



requirements of plants, 280-292 



stagnation of, 303-304 



trace elements, 280, 285, 297 

 Nutrition, modes of, 278-280 



Ocean, bottom, 66-69 



calcium carbonate in, 272-276 



Ocean, circulation in, see Currents 



currents, 42-44, 250 



ecological cycle of, 473-481 



light penetration in, 191-198, 230- 

 233 



nutrient cycle in, 301-308 



nutrients in, 287-289, 305-307 



O2 supply in, 242-251 



pW and carbon dioxide in, 263-265 



photosynthesis in, 235-241 



salinity, 93 



utilization of resources by man, 500- 

 503 



vertical temperature structure of, 

 136, 139-141 



zones of, 30 

 Old-field succession, 436-438 

 Oligotrophic lakes, 287 

 Optimal yield, 344-348 

 Organic matter, decomposition of, 300 



dissolved, 478 

 Orientation, 207-216 



in anadromous fish, 267—268 



in bats, 61 



in bees, 215 



in birds, 355 

 Osmotic pressure, of elasmobranchs, 95 



of natural waters, 93-95 



of plants, 96-97 



of teleost fishes, 95 

 Overturn of lakes, 13 

 Owls, 335, 377, 395 

 Oxidation-reduction potential, 251-253 

 Oxygen, adaptations of aquatic animals, 

 255-256 



availabihty in air, 243, 253 



availability in aquatic environment, 

 244-251 



availabihty in soil, 243, 253 



consumption, 256-257 



effect on distribution, 253-259 



partial pressure in aquatic environ- 

 ment, 255 



pulse, 245 



requirements of animals, 253, 257 



requirements of plants, 253 



saturation values, 244 



supersaturation, in sea and lakes, 

 244-245 



supply to deep waters, 246-251 

 Oyster, population sizes in, 326 



