the seeds are eaten by squirrels. 



Although the rice rat occasionally 

 appears In Zone II, small mammals are usu- 

 ally absent In most of it. Mink, raccoon, 

 beaver and otter may use tupelo gur.,- 

 cypress forests (Zones II and III) in par- 

 ticular. 



FAUNA OF ZONE IV 



Invertebrates 



The invertebrate fauna of Zone IV can 

 be subdivided according to their dominant 

 use of this floodplain zone: 



(1) inundation fauna -- inverte- 

 brates occupying the substrate 

 and water column during periods 

 of flooding 



(2) litter fauna — invertebrates 

 occupying the leaf litter layer 

 during dry periods 



(3) persistent fauna -- inverte- 

 brates occupying the floodplain 

 habitats in various life history 

 stages throughout most of the 

 year. 



Sniffen (1980) characterized the 

 inundation fauna of the Creeping Swamp 

 (NC) floodplain (Zone IV) as a large and 

 diverse component of this small blackwater 

 floodplain. The most conspicuous inverte- 

 brates were six species of "red" lumbricu- 

 lid worms and four species of "white" 

 enchytraeid worms, three tubellarian flat- 

 worm species, and several roundworm spe- 

 cies. Oligochaete worms and copepods were 

 numerically the most abundant inverte- 

 brates (16,470/m2). Isopods, although 

 fewer in number than the worms, were the 

 dominant biomass component (1114 mg dry 

 wt/m2). Ostracods were numerous (829/m^, 

 as were nematodes (4348/m2), Kidge fly 

 larvae, amphipods, water mites and ccllem- 

 bola were also abundant. 



There are relatively few definitive 

 studies of the litter fauna of floodplain 

 communities in Zone IV. Grey (1973) con- 

 ducted the most thorough faunal survey of 

 this particular habitat. His study of the 

 Santee River (SC) floodplain determined 

 that mites (Acari) and springtails (Col- 



lembola) were by far the dominant litter 

 organisms, accounting for about 92% to 95% 

 of the organisms during any season. The 

 mites comprised 48.1% and 77.4% of the 

 total population count in the summer and 

 fall, respectively; the springtails, 47.6% 

 and 13.1%. Both groups are detrital 

 "shredders" important to the decomposition 

 processes in the upper litter and humus 

 layers. 



Earthworms, important food sources 

 for salamanders and shrews, are also an 

 abundant and important component of the 

 litter fauna. Parsons and Wharton (1978) 

 found three genera of earthworms ( Eisenia , 

 Al lolobophora , and Sparganophi lus ) in the 

 floodplain of the Alchovy River (GA). 

 Harper (1938) noted that earthworms 

 (principally the genera Diplocardi a and 

 Helodrilus ) preferred dense, packed flood- 

 plain soils with water tables below 23 cm 

 (9 inches). 



Other invertebrate fauna using Zone 

 IV throughout the year and throughout 

 their entire life cycles are principally 

 crayfish and insects. Some 23 chimney- 

 building floodplain crayfish species occur 

 east of the Mississippi River and 19 east 

 of the Escambia River (FL) (Wharton et al. 

 1981). Several, such as Procambarus 

 pubischelae and £. seminolae , seem to 

 favor blackwater floodplains; others on 

 almost all floodplains are Cambarus 

 dioqenes and Procambarus acutus . Many 

 insect species whose larvae inhabited 

 sloughs and pools within Zones II and III 

 may be found in Zone IV as flying adults 

 during drydown. Mobile species, such as 

 dragonflies and butterflies, span many 

 zones. Some, like the abundant snout 

 butterfly ( Libytheana bachmanii ) and the 

 hackberry butterfly ( Asterocampa c eltis ), 

 can be categorized by their larval prefer- 

 ence for sugarberry, a Zone IV tree. 



Vertebrates 



Amphibians, especially salamanders, 

 are abundant in Zone IV. The marbled sal- 

 amander ( Amby stoma opacum ) is generally 

 restricted to this zone; others such as 

 the mud salamander ( Pseudotriton m ontanus ) 

 seldom occur elsewhere. The dominant 

 plethodontid salamanders include the two- 

 and three-lined salamanders ( Eurycia ). 

 The four-toed salamander ( Hemidactylum ) 

 occurs here and in Zone II. The green and 



90 



