Table 16. Net primary productivity (g dry wt/m /yr) for 

 bottomland hardwood communities (primarily Zone II), com- 

 pared with other wetland and upland environments. 



Community type 



New primary 

 productivity 

 (g dry wt/m^/yr) 



Dwarfed cypress strand (FL) 367 



Okefenokee cypress forest (GA) 595 



Oak-hickory upland (MO) 600 



Cypress-water tupelo (IL) 678 



Drained cypress strand (FL) 681 



Cypress-tupelo (Green Swamp, FL) 760 



Oak-pine uplands (NY) 796 



Slash pine flatwoods (FL) 830 



Northern hardwood upland (NH) 898 



Cypress-hardwood (Green Swamp, FL) 950 



Mature cypress dome (FL) 956 



Elm-ash-sweetgum (Zone IV) (IL) 967 



Spruce-fir upland (Great Smokies) 980 



Upland cove forest (TN) 1050 



Cypress strand (FL) 1111 



Riverine cypress-water tupelo (LA) 1140 



Mixed bottomland hardwoods^ (LA) 1174 



Cypress-water ash creek forest^ (FL) 1607 



Tulip poplar upland forest (TN) 2400 



References 



Carter et al. 1973 



Schlesinger 1978 



Rochow 1974 



Mitsch et al. 1977 



Burns 1978 



Mitsch and Ewel 1979 



Whittaker and Marks 1975 



Golkin 1981 



Whittaker and Marks 1975 



Mitsch and Ewel 1979 



Brown 1981 ^ 



S. Brown (pers. comm. ) 



Whittaker and Marks 1975 



Whittaker and Marks 1975 



Burns 1978 



Conner and Day 1976 



Conner and Day 1976 



Brown 1981 



Whittaker and Marks 1975 



^Sandra Brown, Department of Forestry, University of Illinois, Urbana. 



Red maple-water tupelo-box elder-cottonwood-cypress-swamp dogwood-willow 

 (mix of Zones II and IV with pioneer species). 



''Also contains diamondleaf, oak, sweetgum, red maple (mix of Zones II and IV), 

 Flow partially regulated by low dam. 



ties is probably low because of heavy silt 

 loads. Productivity of the Satilla River 

 and Okefenokee Swamp does not seem to be 

 limited by low nutrient availability and 

 acidic conditions. Brinson observed ex- 

 tensive production of filamentous algae in 

 floodplain ponds during the winter dormant 

 season and suggested that this component 

 may provide a temporary sink for inorganic 

 nutrients during winter and early spring. 



Aquatic vascular productivity can be 

 high in localized areas, depending on 

 light intensity and water velocities. 

 Species that may contribute heavily to 

 community productivity are Alternanthera 



phi loxero ides , Myriophyllum spp., Lemna 

 spp., Sp irodela spp., Egeria densa, 

 Ceratophyllum spp., Lim^nobium spp., and 

 Azolla spp. (Dennis 1973). 



The prominence of the herbaceous 

 ground cover varies dramatically among the 

 forest cover types, as discussed in the 

 previous section on dominance types. In 

 general, the highest herb densities and 

 productivities are found on the driest 

 floodplain sites (heavy growths of various 

 composites follow drydown in Zone IV). 

 This is a function of hydroperiod and 

 light intensities. One species that can 

 produce tremendous amounts of biomass in 



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