Aspen Bibliography

Title

Fine-root production in small experimental gaps in successional mixed boreal forests

Document Type

Book

Source

International Association for Vegetation Science. Key issues in disturbance dynamics in boreal forests: based on contributions presented at the IAVS (International Association for Vegetation Science) workshop on disturbance dynamics in boreal forests held at the University of Quebec in Abiti-Temiscamingue in Rouyn-Noranda, Canada, August 26-30, 1996

Publication Date

8-1998

Abstract

The effects of small 10mx 10m experimental

above-groundgaps on fine-root productionfor the first two years were studiedin threefire-initiatedstandsof the north- western mixed broad-leaf-coniferboreal forest of Quebec. The 48-yr-old forest is dominatedby Populus tremuloides (Tremblingaspen), the 122-yr-oldforest by a mixtureof P. tremuloides,Abies balsamea (balsam fir) and Picea glauca (whitespruce),andthe232-yr-oldforestbyThujaoccidentalis (easternwhitecedar)andA.balsamea,withsomeP.tremu- speciesdynamics(e.g.Brokaw&Scheiner1989;Lorimer loides. 40 root-ingrowthbags were installedin differentloca-

tionsinandaroundeachgap(atgapcenter,1to2meitherside

ofgapedgeandinadjacentcontrolplots).Halfoftheingrowth bagswereharvestedafteroneyearfollowinggapcreation,the other half after two years. Roots were sorted into different

species grouping. Fine-root production was statistically (P < 0.05) largerin the youngest forest comparedto the two older ones after one year, but not after two years. The indi-

vidual species or groups of species increased,decreasedor showednochangeinfine-rootproductioningaps,butoverall wedidnotobserveamajorshiftinspeciesproportionbetween gap and control plots after two years. Some herbs and also Taxus canadensis seemed to benefit in terms of fine-root growthfromsuchsmallopeningsaftertwo years.No statisti- cal differences (P > 0.10) in total fine-root productionwere foundamonglocationswithinandoutsidegapsin eitheryear. However,therewas a cleartendencyfor fine-rootproduction to be smallerin gap centerthanin the otherlocationsfor the two youngersuccessionalforeststhefirstyearaftergapcrea- tion.Weconcludethatsmallabove-groundgaps(i.e.< 100m2) do not produce a significant and long-lasting below-ground gap in termsof total fine-rootproductionin the successional forests investigated.