526 



THE COMMUNITY 



The following year, Bodenheimer (1938) 

 noted that the total weight of plant pro- 

 duction (producers) was greater than that 

 of the herbivores (primary consumers) of 

 an area, and the total weight of the latter 

 must be greater than that of the total pred- 

 ators (secondary consumers). 



Biomass data for domesticated animals 

 and agriculturally important plant species 

 are available, as are data on a variety of 

 organisms computed on less than an annual 

 crop basis.* Table 47 is an example of a 

 standing crop analysis in terms of weight 

 of animals per unit area. 



pounds per acre of lake; allowing for the 

 few small specimens which escaped 

 through the meshes of the seine, Juday 

 (1938) estimated the total fish biomass at 

 about 365 pounds per acre for the period 

 of investigation. 



Community analyses involving biomasses 

 are destined to become more important. 

 Hutchinson (1943b), in a philosophical 

 discussion of food, time, and culture in the 

 anthropological sense, is concerned with the 

 comparison of communities in general with 

 man's societies. He observes that it is usu- 

 ally possible to study any system S from 



Table 47. Fish Biomass of Lake Wingra, Wisconsin, on November 15 and 18, 1936 (After 



Juday, 19S8) 



Kinds of Fishes 



Carp 



Buffalo fish . . . 



Gar fish 



Black bass 



Wall-eyed pike 



Sunfish 



Crappies 



WTiite bass 



Totals 



Numbers 

 Caught 



6000 



652 



2500 



1100 



1000 



20,000 



40,000 



1500 



Total Weight 

 in Pounds 



41,850 

 1300 

 3500 

 1600 

 1500 

 6600 



13,300 

 1900 



Pounds per Acre 

 (Biomass) 



209.0 



6.5 



17.5 



8.0 



7.5 



33.0 



66.0 



9.5 



72,752 



71,550 



357.0 



This table is of interest. Lake Wingra is 

 shallow, with a maximum depth of 14 feet 

 and only a small part of its 200 acre area 

 over 10 feet deep. A small-meshed seine 

 was used, long enough to stretch entirely 

 across the lake and deep enough to cover 

 the entire depth of water. The study in- 

 volved the almost complete removal of 

 fishes from the lake, that is, the removal 

 of almost the entire population of secon- 

 dary consumers of higher grades (large 

 predators), and many primary consumers 

 (herbivores). The total fish crop was 357 



° There is a substantial amount of informa- 

 tion on partial biomasses and data for comput- 

 ing the food necessary to maintain an in- 

 dividual animal. The interested reader will find 

 such values for many domesticated animals and 

 cultivated plants in the U. S. Department of 

 Agriculture Yearbook for 1939, for limnological 

 studies in Chapman (1931), for forest snails 

 in Foster ^937) and Strandine (1941), for 

 arthropods of the forest floor litter in Lunn 

 (1939) and Williams (1941), and for grass- 

 land invertebrates in Wolcott (1937). 



two general viewpoints: (1) the holologi- 

 cal, in which energy and matter changes 

 across the system's boundaries are observed, 

 and (2) the merological, in which the be- 

 havior of individual systems of lower order 

 than S are examined. Here the biomass is 

 thought of as a total community weight 

 per unit of area, consisting of many dif- 

 ferent intracommunity biomasses. 



The original concept of biomass was the 

 weight of a species population per unit of 

 area. This will be called species biomass 

 (b); the total biomass of a community will 

 be called community biomass (B). Com- 

 munity biomass is composed of the sum of 

 many species biomasses that compose the 

 meshes of the food web, and whose popu- 

 lations make up the pyramid of numbers. 

 Such species biomasses may be treated as 

 separate populations. They may be com- 

 puted for separate infracommunity levels— 

 for example, stratum biomass, habitat-niche 

 biomass, trophic level biomass, and the 

 Uke. 



