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Turnover of Detrital Organic Carbon in a Nutrient‐Impacted Everglades Marsh
Author(s) -
DeBusk W. F.,
Reddy K. R.
Publication year - 1998
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1998.03615995006200050045x
Subject(s) - peat , mineralization (soil science) , marsh , plant litter , nutrient , environmental science , environmental chemistry , typha , organic matter , litter , wetland , ecology , chemistry , soil science , soil water , biology
Phosphorus loading to the Everglades from nearby agricultural areas has become a major concern, and is considered to be a significant factor in the encroachment of cattail ( Typha domingensis Pers.) and other rapidly growing vegetation into endemic sawgrass ( Cladium jamaicense Crantz) marsh. The objectives of this research were to evaluate the variability in turnover of organic C in plant and soil detrital pools along a P enrichment gradient in an Everglades marsh and to identify substrate characteristics and environmental factors controlling C turnover. Potential rates of C mineralization in plant litter and peat were determined by measuring aerobic and anaerobic microbial respiration under controlled conditions in laboratory incubations. Potential C mineralization decreased with depth and, consequently, substrate age, in the plant‐soil profile. Within individual detrital pools [standing dead plant material, soil litter layer, surface peat (0–10 cm depth) and subsurface peat (10–30 cm depth)], potential C mineralization decreased down gradient from the source of nutrient loading to WCA‐2A. Overall, 91% of the variability in aerobic C mineralization in peat and plant litter was accounted for by substrate P concentration and lignocellulose composition. Anaerobic C mineralization rates were consistently about one‐third of aerobic rates. Results indicated that organic C turnover in detrital pools in WCA‐2A is significantly affected by accelerated P loading, but is also controlled by O 2 availability and substrate C quality.