alterations will affect the entire food web. More important (the 

 authors contend) is the value of the mangrove system to the marine 

 environment as the mangroves are rapidly disappearing as a result 

 of urbanization. (G.S.) 



Keywords: fungi, mangrove, detritus, Florida 



III-C-9 



De la Cruz, A. A., and B.C. Gabriel. 1973. Caloric, elemental, and nutri- 

 tive value changes in decomposing Juncus roemerianus leaves. Association 

 of Southeastern Biologists Bulletin 20:47" (Abstr.) 



In situ decomposition of Juncus roemerianus (Juncaceae) leaves 

 determined by litterbag method was 0.40/yr. Caloric, elemental, and 

 proximate nutritive analyses of leaves at various stages of life and 

 decay (namely: young, mature, standing dead, partially decayed, decomposed 

 fragments, and particulate detritus) showed the following: (a) increase 

 in caloric content (4630 to 4911 gcal/ash-free g); (b) decrease in 

 carbon (49.75 to 6.38 percent), nitrogen (1.09 to 0.57 percent), 

 phosphorus (0.22 to 0.17 percent); (c) decrease in crude fiber (37 to 

 9 percent), carbohydrate (47 to 11 percent), protein (8 to 4 percent) 

 and fats (2.4 to 0.85 percent). Particulate detritus recovered from 

 litterbags decomposed in incubation flasks at the rate of 0.50/36 days. 

 At intervals of 0, 5, 13, 25, and 36 days, analyses of detritus showed 

 the following: (a) decrease in organic content (67 to 32 percent) and 

 carbon (5.6 to 3.2 percent); (b) increase in nitrogen (0.44 to 1.21 per- 

 cent) and respiration rates (0.36 to 3.63 ppm 0^ hr"^ ash-free g" ) . 

 The increase in N and consequently protein is attributed to conversion 

 of plant-detritus tissue to microbial protoplasm, as evidenced by 

 increased respiration rates. (A. A.) 



Keywords: detritus, Juncus roemerianus , decomposition 



III-C-10 



De la Cruz, A. A. 1975. Proximate nutritive value changes during 

 decomposition of salt marsh plants. Hydrobiologia 47:475-480. 



Recognition of salt marsh plant detritus as a nutritious source of 

 food for estuarine consumers prompted investigation of in situ decom- 

 position and proximate nutritive values of three plants and their detritus; 

 namely: Spartina cynosuroides and Distichlis spicata (Gram.) and 

 Scirpus americanus (Cyperaceae) growing abundantly in Mississippi 

 tidal marshes. During decomposition to particulate detritus, these 

 plants retain 60-70 percent organic content, and the caloric value 

 either remains the same or increases slightly. Crude fiber, carbo- 



108 



