H 



Habitat(s) (see also Adjustment(s) 



to Terrestrial Habitat(s); 



Microhabitats): 



addition of organic matter to, 19 



adjacent segregation of related 



species into, 255 

 and average densities of popula- 

 tions, 219 

 and equilibrium with communities 



through plant succession, 163 

 as affected by dispersal of propa- 



gules in biotic succession, 22 

 carrying capacity of and death 



rate, 211 

 characteristics of sand dune as, 



106-107 

 choice of and threshold limits of 



environmental factors, 10 

 continuing process of change in, 21 

 control of by pond- marsh fish, 85 

 defined, in ecology, 6 

 expression of dominance in, 19 

 fertile, wide variety of species in, 



255 

 food resources of as sustaining 

 populations of competing species 

 because of predation, 252-253 

 forest- edge, in clay sere, 113 

 genetic inheritance of preferences 



for, 251 

 grassland and forests, vertical 



gradients in, 122-123 

 grassland, forest- edge, and forest- 

 interior compared as, 121-122 

 growth rates and environmental 



resistance offered by, 217 

 impoverished, little variety in 



species of, 255 

 in alpine tundra, rugged terrain of, 



316 

 increase in fertility of during 



succession, 207 

 in forest- edge vegetation, 120 

 in lakes: 

 and littoral zone, 69-71 

 and profundal zone, 71-73 

 compared with those in streams, 



59 

 control of in lake management, 27 

 dystrophic, 64 

 eutrophic, 64 

 oligotrophic, 64 

 in streams: 

 falls, 42-43 

 in headwaters, 52 

 invasion of as part of evolution, 



53 

 mud-bottom ponds, 42-43, 43 

 rapids, 42-43, 43 

 riffles, 42-43, 43 

 sand-bottom pools, 42-43, 43 



Habitat(s) (Continued) 

 intertidal: 

 adjustments of organisms of to 



alternate submergence and 



exposure, 352 

 anchoring devices of organisms 



in, 362 

 and infralittoral fringe, 362 

 and midlittoral or balanoid zone, 



362 

 and supralittoral fringe, 362 

 and supralittoral zone, 362 

 and tidal pools, 364 

 avoidance of desiccation by 



organisms in, 362 

 effect of water temperature 



variations on organisms of, 354 

 mud and sand burrows compared 



as, 352 

 proper choice of by animals 



according to zone, 362-363 

 protective devices of animals of, 



352, 364 

 species of animals in, 363 

 large, functioning of natural selec- 

 tion in, 265 

 less favorable: 

 inhabitants of rarely vulnerable 



to epizootics, 231 

 occupation of in years of popula- 

 tion pressure, 150 

 local, persistence of flora and 



fauna in despite mass retreat 



of vegetation, 297 

 marine: 

 adjustments of plankton to 



through flotation mechanisms, 



357-358 

 and characteristics of sublittoral 



zone of balanoid- gastropod- 



thallophyte biome, 363 

 and species in estuaries, 368 

 and zonation in pelycopod- 



annelid biome, 365 

 characteristics of crustaceans 



in, 365 

 coral reefs as, 366-367 

 deep-sea, as unchanged from 



early geological time, 360 

 deep-sea, derivation of organ- 

 isms of from intermediate 



depth organisms, 360 

 deep-sea, development of bio- 

 luminescence by organisms of, 



360 

 deep-sea, examination of cores 



from as providing information 



about ancient forms, 360 

 deep-sea, persistence of ancient 



forms in, 360 

 deep-sea, special structures for 



vision in, 360 

 division of sea into, 351-352 



Habitat(s) (Continued) 



filter-feeding mechanisms of 



organisms in, 361 

 fragility of skeletons of animals 



in, 360 

 gradual changes in to fresh- 

 water habitats, 368 

 light in, 354 

 maintenance of hydrostatic 



equilibrium in, 359 

 muddy-bottom burrowing as 

 characteristic of animals in, 

 365 

 muddy bottom, conditions of, 364 

 muddy- bottom, epifauna in, 365 

 muddy-bottom, food coactions in, 



365-366 

 muddy-bottom, microscopic 



forms in, 365 

 muddy-bottom, plants in, 365 

 muddy-bottom, productivity in, 



366 

 muddy- bottom, species of 



animals in, 365 

 oxygen in, 356 

 pressure in, 353 

 salinity of, 354-356 

 substratum of, 352-353 

 temperatures in, 353-354 

 tidal pools as, 364 

 tides in, 352 

 measuring primary production of 



energy in, 203-204 

 measuring secondary production 



of energy in, 204-205 

 new, invasion of and formation of 

 secondary dispersal center, 

 154 

 new, production of and consequent 



dispersal of species, 150 

 of beavers, 86-87 

 of frogs, 90 

 of muskrats, 86-90 

 of pond fish, 90 

 of salamanders, 90 

 of small mammals in forest 



communities, 136 

 of swamp birds, 90 

 optimum, stabilization of popula- 

 tions as occurring in, 233 

 origination of in ponds, 79 



primary bare areas in, 22 

 saturation of and rise of competi- 

 tion, 253 

 secondary bare area in, 22 

 shape of and sample plots, 32 

 small, functioning of natural 



selection in, 265 

 temperature of and effect on 

 cold-blooded animals, 98 

 use of term in naming aquatic 



communities, 29 

 water conditioning in, 172-173 



422 Index 



