Flooded forest

Apportioning the areas of floodplain occupied by one of the three major aquatic habitats, i.e., open water, herbaceous macrophytes, and flooded forests, and determining their temporal changes remains a challenge. As approximations required for calculations of the organic carbon balance... 

Periphyton accumulations on leaves and branches within flooded forests may be lower than those in floating meadows. For example, Doyle (199D reported a mean of about 40 mg chlorophyll m 2 in the periphyton of floating meadows of Lake Calado, while Alves (1991) measured an average of 10 mg chlorophyll m 2 in the periphyton of the flooded forest near an upland stream in Lake Calado. However, more data on periphyton biomass from a variety of sites are needed before generalizations are warranted. 

Putz (1997) estimated production as uptake of i C by periphyton that grew on artificial cellulose-acetate substrata suspended in several habitats near Manaus. Her results could not be used to compute an areal value for periphyton associated with floating macrophytes due to the complex surface of the natural substrata. To extrapolate her results to areal rates in floodplain forests requires an estimate of leaf area in the euphoric zone per unit area of water. Alves (1991) reported between about 0.5 and 1.5 m2 of leaves in the euphoric zone of flooded forest per m2 of water for simplicity we used 1.0. Based on net productivities measured by Putz (1997) at a site dominated... 

Organic carbon is lost from Amazon flood-plain lakes by permanent burial, emission as CO2 and CH4 to the atmosphere or export to the river. Sufficient data are now available to estimate most of these losses. Methane is produced predominantly in anoxic environments associated with flooded habitats. Methane emission rates have been estimated in a variety of habitats and sites along the central Amazon floodplain (Devol et al. 1988, 1990, 1994, Crill et al. 1988, Bartlett et al. 1988, 1990, Wassmann et al. 1992, Wassmann and Thein 1994, Engle and Melack 2000). The average emission rates encountered in aquatic macrophyte beds, flooded forest and open water, including... 

Throughfall and litterfall from flooded forests represent a complex aspect of nutrient dynamics in floodplain lakes that has received little attention. Filoso (1996) measured wet deposition and throughfall from igapo forest of the Anavilhanas archipelago in the lower Negro River, and calculated that about two thirds of the rain that fell on floodplain lakes in the Anavilhanas was influenced by flooded forest canopy. The deposition of dissolved P increased about seven times after rain was... 

Seasonal and regional differences in the relative importance of N or P limitation occur in the Amazon basin. Most research has concerned phytoplankton, and some recent studies have examined periphyton and floating meadows. Comparable experimental assessments of flooded forests are lacking. 

The continued construction of hydroelectric dams and expansion of agricultural and urban areas adds urgency to increasing our ability to forecast biogeochemical consequences of such developments in the Amazon basin. Applications of limnological understanding to timber management in flooded forests, to fisheries, to conservation of aquatic biodiversity, to control of waterborne disease vectors and to amelioration of... 

Filoso, S., M. R. Williams and Jim Malade. 1999. Composition and deposition of throughfall in a flooded forest archipelago (Anavilhanas, Negro River, Brazil). Biogeochemistry 45 169-195. 

Megonigal J. P., Patrick W. H., Jr., and Faulkner S. P. (1993) Wetland identification in seasonally flooded forest soils soil morphology and redox dynamics. Soil Sci. Soc. Am. J. 57, 140-149. 

Deciduous tropophilous forests deciduous gallery forests deciduous, temporarily flooded forest islands... 

Subevergreen gallery forests evergreen flooded forest islands with Caraipa Uanorum Cuatrec. and C. densifolia Mart, (saladillales)... 

The extent of this silicification process may be significant when the vast number of partially submerged trees in the study area is considered. The slow flowing movement of water within the flooded forests and the preferential attachment of diatoms to the outer wood surfaces may allow for silicon levels to build up sufficiently in microenvironments. Therefore, many of the trees within these flooded forests potentially can become reservoirs of highly reactive silica, disrupting the amount of silicon locally recycled through the freshwater system. 

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