Seasonal responses of consumers of several trophic classes to re- 

 source availability raise interesting questions concerning salt marsh 

 community structure and in particular the relationship between seasonal 

 richness and resource partitioning. The mosaic of vegetational parts 

 increases in the spring when primary production beings. Subsequently, 

 an increase in plant biomass and structural complexity occurs. 



Several strategies are given concerning resource utilization by 

 seasonal versus persistent species. One of these strategies is over- 

 lapping niches. In this situation, each species satisfies its own 

 requirements while jointly using resources with other species. Over- 

 lapping niches lead to severe competitive interactions between species 

 groups and, consequently, decreased diversity. Another strategy in- 

 volves physiological adaptations to particular elements along the 

 temperature-humidity gradient. Seasonal species could thus utilize 

 resources in their zone of physiological tolerance more efficiently 

 than, and without interference from, persistent species. 



The strategy which the author believes to be operating assumes that 

 seasonal and persistent species are both specialists, alleviating com- 

 petition by resource subdivision. Specialization enables more species 

 to coexist in an available habitat. (A. A. and H.D.) 



Keywords: insects, trophic diversity, salt marshes 



V-D-9 



Barnes, R.D, 1953. The ecological distribution of spiders in non-forest 



maritime communities at Beaufort, North Carolina. Ecological Monographs 



23:315-337. 



Spiders as a group constitute one of the best indexes for the 

 investigation of community structure, stratification, and succession 

 of animals. The great degree of adaptive radiation which the order 

 has undergone has resulted in their filling almost every ecological 

 niche. Despite this and other advantages of study, few ecological 

 studies had been made of spiders at the time of writing. Of the nine 

 principal maritime plant communities in the region, the study was 

 concerned with three in which the presence of salt water, directly 

 or indirectly, was the determining factor as to their presence: 

 Spartina alterni flora , Spartina-Distichlis-Salicornia , and Juncus 

 roemerianus . 



The variation in the saline water table was found to be the primary 

 factor determining the formation of the major maritime plant communities 

 and the zonational and successional series in which they occur. On 

 the coast of North Carolina, the zonation and succession of vegetation 

 consist of the following series of communities beginning in the inter- 

 tidal zone and ending in the climax maritime forest: Spartina 



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