THE ENVIRONMENT 



337 



TABLE 17.5 ECOLOGICAL SEASONS AND SOME PLANT AND ANIMAL ASSOCIATIONS' 



Aspect 



Sector 



Duration 



Plants 



Invertebrates 



Vertebrates 



Hiemal 



Hiemine 



No\.-Dec. 



Hibernine Dec. -Mar. 



Emergine Jan. -Apr. 



Lichens and mosses con- 

 spicuous; some mosses 

 form capsules; herbs 

 mostly dead; deciduous 

 trees mostly bare 



Most to all plants are 

 dormant, especially 

 flowering plants 



Vegetative growth, swell- 

 ing buds and sprout- 

 ing foliage but no 

 flowers 



Most enter hibernation; 

 active forms are mostly 

 insects and small; some 

 active insects "swarm" 



Maximum hibernation, 

 but some species are 

 active 



First hibernators emerge 

 from dormancy 



.'\mphibians, reptiles, and 

 some mammals entering 

 hibernation; a few slug- 

 gish amphibians are 

 found; last bird migra- 

 tion 



Maximum hibernation, 

 except for some birds 

 and mammals 



Hibernators emerge; some 

 amphibians enter breed- 

 ing ponds; migrant 

 birds appear 



Vernal 



Prevernine Mar. -May 



First spring 

 pear 



flowers ap- 



Vernine 



Apr-June 



Plants fully foliated; 

 shade-tolerant species 

 flower; maximum flow- 

 ering 



Most hibernators emerge 

 and activity increases 



New forms become ac- 

 tive; become abundant 

 throughout habitat in 

 tree, shrub, etc., layers. 



Most amphibians enter 

 ponds and lay eggs; 

 resident birds and mam- 

 mals begin reproductive 

 activities 



Many amphibians become 

 subterranean or ter- 

 restrial; reptile repro- 

 ductive activities; peak 

 of migrant bird entry; 

 birds are nesting and 

 mammals bearing young 



Aestival Cisaestine May-Aug. 



Aestine 



July-Aug. 



Fully foliated; reduced 

 flowering, only sum- 

 mer-blooming species; 

 period of maximum 

 vegetative growth 



Habitat dries; fruiting of 

 some herbs; many wilt 

 or dry; flowering very 

 limited 



Reduction of midday ac- 

 tivity in diurnal forms 



Last terrestrial amphib- 

 ians aestivate; reptiles 

 decrease during mid- 

 day; bird nesting peak; 

 diurnal mammals re- 

 duce midday activity 

 Many aestivate; foliage Reptiles and some mam- 

 insects reach peak mals aestivate; birds be- 

 come quiet and enter 

 molt.somemigrate south 



Autumnal Serotinine Aug. -Oct. 



Autumnine Oct. -Nov. 



Last fruits ripen; herb 

 leaves become yellowed 

 and ragged; blooming 

 and fruiting of fall- 

 flowering species 



Deciduous leaves color 

 and fall; herbs mostly 

 dead; fungi form fruit- 

 ing bodies 



Many species disappear Renewed activity of some 



from the surface 

 higher layers 



and amphibians and rep- 

 tiles; maximum south- 

 ward bird migration; 

 maximum mammal pop- 

 ulations 

 Insects and spiders move Some amphibian and rep- 

 from plants to ground tile activity when warm; 



birds mostly residents; 

 mammals decrease 



^After Macnab, J. A. 1958, Biotic Aspectation in the Coast Range Mountains of Northwest Oregon Ecological Monographs 28: 21-54. 



The dynamic nature of success is revealed by living 

 organisms. Living creatures are mostly evolved de- 

 scendants of unsuccessful (extinct) species. More- 

 over, most living species are about a million years 



old; only a few really old species are known and none 

 of these appear to date back as far as one-half billion 

 years in the probably more than three billion years of 

 life. Even if discussion is limited to the relatively 



