Tree species diversity increases fine root productivity through increased soil volume filling

Journal of Ecology - Tập 101 Số 1 - Trang 210-219 - 2013
Brian W. Brassard1, Han Y. H. Chen1, Xavier Cavard2, Jérôme Laganière3, Peter B. Reich4,5, Yves Bergeron2, David Paré3, Zhongshun Yuan1
1Faculty of Natural Resources Management, Lakehead University, 955 Oliver Rd., Thunder Bay, ON, P7B 5E1, Canada
2Université du Québec en Abitibi‐Témiscamingue Chaire industrielle CRSNG‐UQAT‐UQAM en aménagement forestier durable 445 boulevard de l'Université Rouyn‐Noranda QC J9X 5E4 Canada
3Natural Resources Canada Canadian Forest Service, Laurentian Forestry Centre 1055 du P.E.P.S., P.O. Box 10380 Stn Sainte‐Foy QC G1V 4C7 Canada
4Department of Forest Resources University of Minnesota 115 Green Hall, 1530 Cleveland Ave. N. St. Paul MN 55108‐6112 USA
5Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW 2753, Australia

Tóm tắt

Summary Although fine roots (< 2 mm in diameter) account for a major share of the production of terrestrial ecosystems, diversity effects on fine root productivity and their mechanisms remain unclear. We hypothesized that: (i) fine root productivity increases with tree species diversity, (ii) higher fine root productivity is a result of greater soil volume filling due to species‐specific patterns of root placement and proliferation, and (iii) differences in fine root productivity and soil volume filling associated with tree species diversity are more pronounced in summer when plants are physiologically active and demand for water and nutrients is at its greatest. We investigated the effects of tree species diversity on fine root productivity and soil volume filling of boreal forest stands that have grown naturally for 85 years on similar sites. Annual fine root production was 19–83% higher in evenly mixed‐ than single‐species‐dominated stands, and increased with tree species evenness, but not tree species richness. Fine root biomass was higher in evenly mixed‐ than single‐species‐dominated stands in summer months, but not in spring or fall. Higher fine root productivity in evenly mixed‐ than single‐species‐dominated stands was realized by filling more soil volume horizontally and vertically in the forest floor in the mixtures of deep‐ and shallow‐rooted species vs. the deeper mineral soil in the mixtures of deep‐rooted species. Synthesis. Our results provide some of the first direct evidence for below‐ground species complementarity in heterogeneous natural forests, by demonstrating that tree species evenness increases fine root productivity by filling/exploiting the soil environment more completely in space and time, driven by differences in the inherent rooting traits of the component species and variations of root growth within species.

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Tài liệu tham khảo

10.1051/forest:2003077

10.1139/x00-141

10.1139/x02-034

10.1007/s10342-005-0075-5

10.1080/07352680902776572

10.1139/X07-125

10.1111/j.1365-2435.2010.01769.x

10.1007/BF01416099

10.1073/pnas.0805962105

10.1126/science.1189736

Casper B., 2000, The Ecological Consequences of Environmental Heterogeneity, 111

10.1146/annurev.ecolsys.28.1.545

10.1111/j.1654-1103.2011.01311.x

10.1111/j.1600-0706.2011.19294.x

10.1126/science.1183506

Environment Canada(2011)Canadian Climate Normals 1981–2010.http://www.climate.weatheroffice.ec.gc.ca/climate_normals/results_e.html. Accessed on June 25 2011.

10.1139/x96-170

10.1016/S0378-1127(01)00575-8

10.1890/0012-9658(1999)080[1118:EATQII]2.0.CO;2

10.2307/2265780

10.1093/treephys/15.5.317

10.1111/j.1365-2745.2005.01067.x

10.1111/j.1469-8137.2004.01015.x

Honer T.G., 1983, Metric Timber Tables for the Commercial Tree Species of Central and Eastern Canada

10.1890/04-0922

10.1007/s10021-009-9259-z

10.1038/nature10282

10.1073/pnas.94.14.7362

10.1007/BF00333714

10.1017/CBO9780511623516

10.1126/science.1150726

10.1111/j.1365-2745.2011.01906.x

10.1139/x05-112

10.1007/s00442-012-2259-2

10.1007/s004420000507

10.5558/tfc77351-2

10.2307/1938874

10.1007/s00442-009-1352-7

10.1007/s10021-009-9271-3

10.1046/j.1469-8137.2000.00677.x

10.1126/science.1215855

10.2307/2261181

10.1007/BF02182644

10.1016/j.foreco.2008.10.036

10.1890/0012-9615(2002)072[0293:FRAONN]2.0.CO;2

R Development Core Team, 2011, R version 2.11

10.1007/s00442-007-0706-2

Rowe J.S., 1972, Forest Regions of Canada

10.1111/j.1365-2745.2006.01124.x

10.1016/S0378-1127(01)00708-3

10.1890/10-0773.1

10.1007/s10021-010-9383-9

Soil Classification Working Group, 1998, The Canadian System of Soil Classification

10.1111/j.1600-0587.2010.06455.x

Taylor K.C. Arnup R.W. Meredith M.P. Parton W.J.&Nieppola J.(2000)A Field Guide to Forest Ecosystems of Northeastern Ontario 2ndedn. NEST Field Guide FG‐01 Northeast Science and Technology Ontario Ministry of Natural Resources Timmins Ontario Canada.

10.1023/A:1004313515294

10.2307/3546757

Warton D.I.(2007)The ‘SMATR’ Package for R. Version 2.1.http://cran.r-project.org/web/packages/smatr/index.html.

Wendel G.W.&Smith H.C.(1990)Silvics of North America: 1. Conifers. Pinus strobus L. – Eastern White Pine(edsR.M.Burns&B.H.Honkala) pp.476–488.U. S. Department of Agriculture Forest Service Washington DC USA.

10.1080/07352689.2010.483579

10.1111/j.1365-2745.2011.01944.x