Little bluestem litter dynamics in Minnesota old fields

Abstract

We studied the decay and nitrogen dynamics of little bluestem (Schizachyrium scoparium) litter in fertilized and unfertilized Minnesota old fields, using the litterbag technique. Annual decay rates and nitrogen leaching losses during the first month of decay were highly correlated with N content of litter and not with fertilizer additions. After the first month of decay, nitrogen was immobilized for at least 18 months. In contrast to decay rates and early N leaching losses, these immobilization rates were correlated with the amount of ammonium nitrate added in fertilizer rather than with initial %N. Therefore, litter quality and exogenous nitrogen supply appear to have different and independent effects on decay rates and N dynamics of little bluestem litter.

Effects of fire frequency on oak litter decomposition and nitrogen dynamics

“…1), so the lack of site eVects on rates of decomposition was surprising. Previous studies investigating the role of exogenous and litter N on decomposition also have found a lack of an eVect of exogenous N supply on decomposition (McClaugherty et al 1985;Prescott 1995;Knorr et al 2005) including previous studies at Cedar Creek (Pastor et al 1987;Hobbie 2005). However, some studies investigating the eVect of N fertilization on decomposition have shown results ranging from positive (O'Connell 1994;Hobbie 2005) to negative (Fog 1988;Prescott 1995) eVects of exogenous N on rates of mass loss.…”

Nitrogen supply differentially affects litter decomposition rates and nitrogen dynamics of sub-arctic bog species

“…In some studies, increased N supply led to increased litter N concentrations (Robinson et al 1995), although opposite results have also been found (Pastor et al 1987;Aerts and De Caluwe 1997). In general, litters with higher N-concentrations decompose faster (Robinson et al 1995;Aerts 1997;Kö chy and Wilson 1997).…”

“…Thus, potentially stimulating effects of N addition on N mineralization from decomposing litter may be counteracted by interactions with secondary compounds in that litter, leading to chemical immobilization of the added N (e.g. Pastor et al 1987;Hobbie and Vitousek 2000).…”

Effects of Nitrogen Deposition on Foliar Litter Decomposition and C, N, Ca, and P Dynamics in a Regenerating Forest

“…Many other studies, however reported either lowered decay rates Carreiro et al, 2000) or no significant change (McClaugherty et al, 1987;Pastor et al, 1987;Hunt et al, 1988;Prescott, 1995;Bryant et al, 1998;Carreiro et al, 2000). The objectives of this study was to evaluate whether external N inputs have an effect on litter decomposition and on C, N, Ca and P dynamics in the forest floor of a regenerating hardwood forest and whether liming can reverse these effects.…”

“…However some studies have reported accelerated decay rates in litter in response to increased external nitrogen inputs (Hunt et al, 1988;Carreiro et al, 2000;Hobbie, 2000;Hobbie and Vitousek, 2000) or no significant change (McClaugherty et al, 1987;Pastor et al, 1987;Hunt et al, 1988;Prescott, 1995;Bryant et al, 1998;Carreiro et al, 2000). Generally, high doses of external nitrogen accelerate decomposition when plant tissues have low contents of lignin and other recalcitrant compounds, but decelerate decomposition rate when high lignin contents are present (Berg, 1986;Fog, 1988;Berg and Matzner, 1997).…”