the time may not be far off when work of this kind 

 may become possible. 



It does not seem feasible to combine the diverse 

 factors discussed above into a single classification. 

 However, there may be some value in an outline 

 that groups the streams of California under their 

 biotic zones (intro. fig. 13) (which in turn are related to 

 altitude, temperature, precipitation, vegetation, and 

 faunal origins) and, secondarily, according to source 

 and permanence of water. 



Classification of the Streams of California 



(Based on biotic provinces and source and 

 permanence of water) 



. Alpine (Arctic Alpine Life Zone; above timber- 

 line, Sierra and White Mountains) 



1. Glacial "milk" streams (Coness Creek) 



2. Snow-melt intermittent (inlets and outlets of 

 many high Sierra lakes above 9,000 feet) 



3. Spring- and snow-fed permanent (Virginia Creek) 



B. Montane (Hudsonian, Canadian, and Transition 

 zones; Boreal coniferous, midelevations, Sierra 

 Nevada, North Coast Range, and southern Calif- 

 ornia Mountains) 



1. Snow-melt intermittent (Angora Creek) 



2. Spring- and snow-fed permanent (Sagehen, Glen 

 Alpine, American, Tuolumne) 



C. North Coast Redwood (Transition Life Zone; Moist 

 Sequoia forest) 



1. Spring-fed redwood creeks 



2. Redwood phase of north coastal rivers (Smith R., 

 Eel R., Russian R., etc.) 



'D. South and Central Coast Range and Coast (Upper 

 Sonoran Life Zone; Open coast, closed-cone pine 

 forest, broad sclerophyll woodland) 



intermittent (Temescal 



1. Short-flow intermittent 



2. Long-flow, fluctuating 

 Creek) 



3. Permanent streams (Wildcat Creek, Carmel R., 

 Big Sur, etc.) 



E. Valley foothill (Upper Sonoran; Digger Pine-Oak 

 Zone Chaparral; moderate gradients) 



1. Short-flow intermittent 



2. Long-flow fluctuating intermittent (Dry Creek, 

 Fresno Co.) 



3. Spring-fed permanent streams 



4. Foothill phase of main rivers (Tuolumne R., 

 Stanislaus R., etc.) 



F. Central Valley (Lower Sonoran Life Zone; grass- 

 land, agricultural, flat) 



1. Long-flow fluctuating intermittent (Putah Creek) 



2. Permanent plant-choked sloughs (irrigation run- 

 off) 



3. Valley phase of large rivers (Sacramento, San 

 Joaquin rivers, and lower tributaries 



G. Desert Foothill (Upper Sonoran Life Zone; Pifton 

 Pine-Juniper, Chaparral) 



1. Short-flow intermittent 



2. Long-flow fluctuating intermittent (lower 

 Walker R.) 



15 



Usinger: Introduction 



3. Spring-foil permanent (lower Carson If., Hoi 

 Crook) 



4. Foothill phase of main rivers (Truckee R.) 



H. Desert (Lower Sonoran; Arteim ia, Larrea, Me-qmte) 



1. Short-flow intermittent (Mojave R.) 



2. Sporadic intermittent (Amargpsa K.) 



3. Fluctuating intermittent 



4. Spring- fed permanent (Owens R., Hat (reek, 

 Laurel Crook, Man, moth Creek, Hot Sprint' run- 

 offs, Death Valley, etc.) 



5. Desert phase of largo rivers (Colorado R.) 



Lakes 



Standing waters such as lakes and ponds differ 

 strikingly from streams not only in superficial appear- 

 ance but also in physical and biotic characterisl 

 In general, water movement is less of a dominating 

 influence, and temperature and oxygen supply are 

 more important. Temperature, in particular, exercises 

 a profound effect because of the following inherent 

 thermal properties of water: (1) specific heat, which 

 is the greatest of all but a few rare substances; 

 (2) latent heat of fusion, which requires that eight) 

 times as much heat be absorbed to transform ice to 

 water at 0°C(and a similar amount given off to reverse 

 the process) as is required to heat or cool water by 

 1°C; (3) thermal conductivity, which is so low that 

 heat transfer in lakes is largely dependent on convec- 

 tion currents and wind action; (4) density (intro. fig. 1 7), 

 which is greatest at 4°C (39.2°F), so that water sinks 

 as it cools to 4°C and then rises as it drops below 

 this, forming ice at the surface rather than at the 

 bottom; (5) evaporation, which results in heat loss 

 (cooling); (6) transparency, which determines the depth 

 of light penetration and hence also the limits of the 

 photosynthetic zone; and (7) solvent action, which is 

 very great and, in the case of oxygen, is greatest at 

 low temperatures so that cold water can hold more 

 dissolved oxygen than warm water. 



As a result of these properties lakes are warmed 

 slowly in the summer, cooled in the winter, and strat- 

 ified at certain times of the year (intro. fig. 18). The 

 period of summer stratification is characterized bj an 



TEMPERATURE 



JO' 



/. 000000 



-0399670 



Intro, fig. 17. Graph showing the relation between density 

 and temperature in pure water (Welch, 1952). 



