Elevated CO2 enrichment induces a differential biomass response in a mixed species temperate forest plantation.
In a free-air carbon dioxide (CO(2)) enrichment study (BangorFACE), Alnus glutinosa, Betula pendula and Fagus sylvatica were planted in areas of one-, two- and three-species mixtures (n = 4). The trees were exposed to ambient or elevated CO(2) (580 μmol mol(-1)) for 4 yr, and aboveground growth characteristics were measured. In monoculture, the mean effect of CO(2) enrichment on aboveground woody biomass was + 29, + 22 and + 16% for A. glutinosa, F. sylvatica and B. pendula, respectively. When the same species were grown in polyculture, the response to CO(2) switched to + 10, + 7 and 0% for A. glutinosa, B. pendula and F. sylvatica, respectively. In ambient atmosphere, our species grown in polyculture increased aboveground woody biomass from 12.9 ± 1.4 to 18.9 ± 1.0 kg m(-2), whereas, in an elevated CO(2) atmosphere, aboveground woody biomass increased from 15.2 ± 0.6 to 20.2 ± 0.6 kg m(-2). The overyielding effect of polyculture was smaller (+ 7%) in elevated CO(2) than in an ambient atmosphere (+ 18%). Our results show that the aboveground response to elevated CO(2) is affected significantly by intra- and interspecific competition, and that the elevated CO(2) response may be reduced in forest communities comprising tree species with contrasting functional traits.
School of the Environment, Natural Resources and Geography, Bangor University, Gwynedd, LL57 2UW, UK.|Centre for Ecology & Hydrology, Environment Centre Wales, Bangor, Gwynedd, LL57 2UW, UK.
Andrew R
AR
Smith
School of Agriculture, Policy and Development, University of Reading, Reading, Berkshire, RG6 6AR, UK.
Martin
M
Lukac
School of the Environment, Natural Resources and Geography, Bangor University, Gwynedd, LL57 2UW, UK.
Robin
R
Hood
School of the Environment, Natural Resources and Geography, Bangor University, Gwynedd, LL57 2UW, UK.
John R
JR
Healey
IBIMET-CNR, Via Caproni, 8-50145, Firenze, Italy.|FoxLab, Fondazione E. Mach, Via Mach 1, 38010, San Michele a/Adige (TN), Italy.
Franco
F
Miglietta
Institute of Forest Ecology, Universität für Bodenkultur (BOKU), 1190, Vienna, Austria.
Douglas L
DL
Godbold
D018533:Biomass; D002245:Carbon Dioxide / Q000494:pharmacology*; D017753:Ecosystem; D005308:Fertilizers; D005651:Fumigation; D009584:Nitrogen / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018547:Plant Stems / Q000033:anatomy & histology / Q000187:drug effects; D012044:Regression Analysis; D012621:Seasons; D013045:Species Specificity; D014197:Trees / Q000033:anatomy & histology / Q000187:drug effects* / Q000254:growth & development*; D006113:United Kingdom
D005308:Fertilizers; D002245:Carbon Dioxide; D009584:Nitrogen