Juniperus virginiana encroachment into upland oak forests alters arbuscular mycorrhizal abundance and litter chemistry

Williams, RJ; Hallgren, SW; Wilson, GWT; Palmer, MW

HERO ID

2009654

Reference Type

Journal Article

Year

2013

HERO ID 2009654
In Press No
Year 2013
Title Juniperus virginiana encroachment into upland oak forests alters arbuscular mycorrhizal abundance and litter chemistry
Authors Williams, RJ; Hallgren, SW; Wilson, GWT; Palmer, MW
Journal Applied Soil Ecology
Volume 65
Page Numbers 23-30
Abstract Upland oak forests in the ecotone between the eastern deciduous forest and the southern Great Plains are threatened by encroachment of eastern redcedar (Juniperus virginiana) due to fire suppression. The rapid rate of encroachment caused concern about concomitant alterations of site characteristics including nutrient cycling and the soil microbial communities (SMC) that could lead to positive feedbacks reinforcing eastern redcedar encroachment. We studied eight upland oak forests across central and western Oklahoma with stands representing three levels of encroachment: oak-dominated, eastern redcedar-dominated, and an intermediate mixture of both species. We analyzed litter chemistry (carbon, lignin, and nitrogen), soil chemistry (soil organic matter, NH4N, NO3-N, PO4, K, and pH), and profiled soil microbial communities using phospholipid fatty acid analysis (PLFA). Eastern redcedar encroachment was accompanied by reduced litter carbon along with higher levels of arbuscular mycorrhizal (AM) fungi while litter N was lower in mixed stands. However, we detected no change in soil chemistry. Our results indicate eastern redcedar encroachment in these upland oak forests reduced litter quality and altered the SMC through increases in AM fungi, a symbiont associated with eastern redcedar. These alterations may create positive soil-microbial feedbacks by reducing the fitness of the dominant oak species and facilitating rapid increase in eastern redcedar in this threatened, oak-dominated ecosystem. (C) 2013 Elsevier B.V. All rights reserved.
Doi 10.1016/j.apsoil.2012.12.020
Wosid WOS:000316584000003
Is Certified Translation No
Dupe Override No
Is Public Yes
Keyword Arbuscular mycorrhizae; PLFA; Quercus stellata; Soil microbial communities; Juniperus virginiana