ISSN:
1435-0661
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Larix decidua Miller], red oak [Quercus rubra L.], red pine [Pinus resinosa Ait.], white pine [Pinus strobus L.], and Norway spruce [Picea abies (L.) Karst]) and one containing six grass species (big bluestem [Andropogon gerardi Vitm.], indiangrass [Sorghastrum nutans (L.) Nash], prairie sandreed [Calamovilfa longifolia (Hook) Scrib.], switchgrass [Panicum virgatum L.], little bluestem [Schizachyrium scoparium (Michx.) Nash.], and sideoats grama [Bouteloua curtipendula (Michx.) Torr.]). The grass monocultures are burned annually. Souls were wet sieved into four size classes (〉2000, 250–2000, 53–250, and 〈53μm). Unsieved soil was incubated aerobically for 30 and 387 d to examine C and net N mineralization. For tree species, aggregate weighted mean diameter (WMD) differed between species (P=0.01), and correlated positively with fungal biomass (r=0.56). Large macroaggregate (〉2000 μm) C concentration ranged from 15 to 26 g kg–1, and was lowest for Norway spruce and red oak (P=0.07). Aggregate WMD correlated weakly (and negatively) with potentially mineralizable N (r=0.57) and in situ net N mineralization (r=0.49). Grass species had no effect on aggregate-size distribution or organic matter concentration in spite of twofold differences in root biomass and threefold differences in N cycling rates. Species-induced changes in soil aggregation explained little of the variation in whole-soil C and N cycling rates, and therefore unlikely to be an important mechanism explaining species effects on ecosystem processes.
Type of Medium:
Electronic Resource
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