Woody plant encroachment by Juniperus virginiana in a mesic native grassland promtoes rapid carbon and nitrogen accrual

dc.contributor.authorMcKinley, D. C.
dc.contributor.authorBlair, J. M.
dc.date.accessioned2012-02-10T14:41:47Z
dc.date.available2012-02-10T14:41:47Z
dc.date.issued2008
dc.description.abstractThe cover and abundance of Juniperus virginiana L. in the U.S. Central Plains are rapidly increasing, largely as a result of changing land-use practices that alter fire regimes in native grassland communities. Little is known about how conversion of native grasslands to Juniperus-dominated forests alters soil nutrient availability and ecosystem storage of carbon (C) and nitrogen (N), although such land-cover changes have important implications for local ecosystem dynamics, as well as regional C and N budgets. Four replicate native grasslands and adjacent areas of recent J. virginiana encroachment were selected to assess potential changes in soil N availability, leaf-level photosynthesis, and major ecosystem C and N pools. Net N mineralization rates were assessed in situ over two years, and changes in labile soil organic pools (potential C and N mineralization rates and microbial biomass C and N) were determined. Photosynthetic nitrogen use efficiencies (PNUE) were used to examine differences in instantaneous leaf-level N use in C uptake. Comparisons of ecosystem C and N stocks revealed significant C and N accrual in both plant biomass and soils in these newly established forests, without changes in labile soil N pools. There were few differences in monthly in situ net N mineralization rates, although cumulative annual net N mineralization was greater in forest soils compared to grasslands. Conversely, potential C mineralization was significantly reduced in forest soils. Encroachment by J. virginiana into grasslands results in rapid accretion of ecosystem C and N in plant and soil pools with little apparent change in N availability. Widespread increases in the cover of woody plants, like J. virginiana, in areas formerly dominated by graminoid species suggest an increasing role of expanding woodlands and forests as regional C sinks in the central U.S.
dc.format.extent454–468
dc.identifier1432-9840
dc.identifier.citationMcKinley, D. C. and Blair, J. M. 2008. "<a href="https://repository.si.edu/handle/10088/17732">Woody plant encroachment by Juniperus virginiana in a mesic native grassland promtoes rapid carbon and nitrogen accrual</a>." <em>Ecosystems</em>, 11 454–468.
dc.identifier.issn1432-9840
dc.identifier.urihttp://hdl.handle.net/10088/17732
dc.relation.ispartofEcosystems 11
dc.titleWoody plant encroachment by Juniperus virginiana in a mesic native grassland promtoes rapid carbon and nitrogen accrual
dc.typearticle
sro.description.unitSERC
sro.identifier.itemID74524
sro.identifier.refworksID59372
sro.identifier.urlhttps://repository.si.edu/handle/10088/17732

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