Vegetation . Sabine Refuge is located on the Gulf Coastal Plain. Soil 

 salinity, elevation, and fire are the chief factors regulating vegetation on 

 the lands. The dominant plant on all areas except the lowest elevations is 

 marshhay cordgrass; it forms rank stands that cover thousands of acres. This 

 dominant species is characteristic of brackish marshes throughout the entire 

 gulf coast region. Salt grass frequently replaces marshhay cordgrass (or 

 codominates) in low areas subject to flooding by brackish water. Rushes and 

 sedges commonly associated with cordgrass include Olney's threesquare ( Scirpus 

 olneyi ), saltmarsh bulrush ( Scirpus robustus ), and nutgrass ( Cyperus sp. ). 

 Grazed lakefront meadows often harbor jointgrass ( Paspalum vaginatum ); the 

 tail slopes of ridges are commonly dominated by bullwhip (or southern bulrush, 

 Scirpus californicus ), hogcane ( Spartina cynosuroides ), and/or roseau cane. 

 The highest elevations of some ridges are often covered with the latter species 

 and/or gulf cordgrass. 



Grazing and fires can disturb the natural succession toward marshhay cord- 

 grass and encourage the growth of annuals, such as panic grass ( Panicum 

 dichotomiflorum ), sprangletop, and millet. These annuals are excellent duck 

 and goose food. 



Prior to the mid-1950's, sewgrass ( Cladium jamaicensis ) dominated exten- 

 sive low areas of the refuge marshes. A die-off (presumably due to high soil 

 -alinity; Valentine, 1962) occurred following hurricane Audrey (1957), and 

 these areas were invaded by emergents such as bulltongue, millet, and smart- 

 weed ( Polygonum spp. ). 



The vegetation of the impoundments and natural ponds depends almost en- 

 tirely on the water levels and salinities. Floating and submerged vegetation 

 found in deeper portions of water bodies include white water lily ( Nymphaea 

 odorata ), duckweed, pondweed, and coontail ( Ceratophyllum demersum ). Sedges, 

 rushes, and other emergents line the borders of standing water bodies; alliga- 

 torweed is also found here. Roseau cane, maidencane, hogcane, or marshhay 

 cordgrass may dominate the tops of levees. 



Wildlife . The majority of the faunal groups of Sabine Refuge are aquatic 

 or semiaquatic. The numerous canal spoil banks have allowed several terres- 

 trial mammals to penetrate the interior of refuge lands - white-tailed deer, 

 grey fox, opossum, skunk, and armadillo. Swamp rabbits, cottontails, and 

 small rodents are also present. 



Economically important mammals include the mink, otter, muskrat, and 

 nutria. The latter two species are voracious feeders on rushes and sedges. 

 During population explosions, they frequently denude large areas of land. 

 These extensive "eatouts" then may become shallow ponds and undergo invasion 

 by openwater species. When present in smaller numbers, these rodents serve as 

 one important mechanism to opening dense stands of vegetation to waterfowl and 

 other species (Lynch et al., 1947). 



75 



