Soil and root respiration in mature Alaskan black spruce forests that vary in soil organic matter decomposition rates

Climate warming at high latitudes is expected to increase root and microbial respiration and thus cause an increase in soil respiration. We measured the root and microbial components of soil respiration near Fairbanks, Alaska, in 2000 and 2001, in three black spruce (Picea mariana (Mill) B.S.P.) forests. We hypothesized faster decomposition correlates with greater amounts of both root and microbial contributions to soil respiration. Contrary to our prediction, the site with the coolest summer soil temperatures and slowest decomposition (site identification "high-np") had signifi- cantly (p < 0.05) greater growing season soil respiration (485 g C·m -2 ·year -1 ) than the two other sites (372 and 332 g C·m -2 ·year -1 ). Spruce C allocation to root respiration was significantly greater, and fine-root N concentration was 10% and 12% greater (p < 0.05) at high-np than at the other two sites. High-np spruce foliage was also more enriched in 13 C and depleted in 15 N, suggesting either lower available moisture or slower N turnover. Either factor could drive greater C allocation to roots; however, a literature review suggests moisture deficit corresponds to greater C allocation to roots in black spruce forests across the boreal ecosystem. Controls on spruce C allocation need to be resolved before making the generalization that soil respiration will increase with warming in this forest type. Resume : Le rechauffement du climat aux latitudes elevees devrait augmenter la contribution tant des racines que des decomposeurs heterotrophes a la respiration du sol. Les auteurs mesure les composantes racinaires et heterotrophes de la respiration du sol pres de Fairbanks en Alaska, en 2000 et 2001, dans trois forets d'epinette noire (Picea mariana (Mill.) B.S.P.) situees a differents endroits dans le paysage. Ils ont assume qu'une decomposition plus rapide corres- pondrait a une plus grande contribution racinaire et heterotrophe a la respiration du sol. Contrairement a leurs predic- tions cependant, la respiration du sol pendant la saison de croissance etait significativement plus elevee (p < 0,05) dans le site avec les temperatures estivales du sol les plus froides et la decomposition la plus lente (site ID « np-eleve »)

[1]  J. Aber,et al.  Soil warming and carbon-cycle feedbacks to the climate system. , 2002, Science.

[2]  李幼升,et al.  Ph , 1989 .

[3]  D. Jacob,et al.  An intercomparison and evaluation of aircraft-derived and simulated CO from seven chemical transport models during the TRACE-P experiment , 2003 .

[4]  F. Chapin,et al.  Scale-dependent environmental controls over species composition in Alaskan black spruce communities , 2006 .

[5]  Harden,et al.  Sensitivity of boreal forest carbon balance to soil thaw , 1998, Science.

[6]  K. Cleve,et al.  Relationships between CO2 evolution from soil, substrate temperature, and substrate moisture in four mature forest types in interior Alaska , 1985 .

[7]  C. Körner,et al.  A global survey of carbon isotope discrimination in plants from high altitude , 2004, Oecologia.

[8]  S. Gower,et al.  CARBON DYNAMICS OF ROCKY MOUNTAIN DOUGLAS-FIR: INFLUENCE OF WATER AND NUTRIENT AVAILABILITY' , 1992 .

[9]  John M. Norman,et al.  Carbon distribution and aboveground net primary production in aspen, jack pine, and black spruce stands in Saskatchewan and Manitoba, Canada , 1997 .

[10]  S. Gower,et al.  Soil surface CO2 flux in a boreal black spruce fire chronosequence , 2002 .

[11]  J. Vogel,et al.  Small root exclusion collars provide reasonable estimates of root respiration when measured during the growing season of installation , 2005 .

[12]  Leslie A. Viereck,et al.  Productivity and nutrient cycling in taiga forest ecosystems , 1983 .

[13]  S. Moosavi,et al.  Controls on CH4 and CO2 emissions along two moisture gradients in the Canadian boreal zone , 1997 .

[14]  H. Beltrami,et al.  Soil CO2 production and surface flux at four climate observatories in eastern Canada , 2002 .

[15]  Takahiro Kohno,et al.  Soil carbon cycling at a black spruce (Picea mariana) forest stand in Saskatchewan, Canada , 1997 .

[16]  Current Perspectives in Microbial Ecology. , 1985 .

[17]  K. Nadelhoffer,et al.  Roots exert a strong influence on the temperature sensitivityof soil respiration , 1998, Nature.

[18]  Wilfred M. Post,et al.  Soil carbon pools and world life zones , 1982, Nature.

[19]  Sune Linder,et al.  Botany: Constraints to growth of boreal forests , 2000, Nature.

[20]  Charles T. Garten,et al.  Separating root and soil microbial contributions to soil respiration: A review of methods and observations , 2000 .

[21]  Susan E. Trumbore,et al.  AGE OF SOIL ORGANIC MATTER AND SOIL RESPIRATION: RADIOCARBON CONSTRAINTS ON BELOWGROUND C DYNAMICS , 2000 .

[22]  P. Jarvis,et al.  Temporal and spatial variation of soil CO2 efflux in a Canadian boreal forest , 2000 .

[23]  J. Gosz,et al.  Effects of trenching on soil processes and properties in a New Mexico mixed-conifer forest , 1986, Biology and Fertility of Soils.

[24]  C. C. Grier,et al.  Above- and below-ground net production in 40-year-old Douglas-fir stands on low and high productivity sites , 1981 .

[25]  R C Littell,et al.  Statistical analysis of repeated measures data using SAS procedures. , 1998, Journal of animal science.

[26]  P. Reich,et al.  Acclimation of respiration to temperature and CO2 in seedlings of boreal tree species in relation to plant size and relative growth rate , 1999 .

[27]  Chien-Lu Ping,et al.  Soil organic carbon and CO2 respiration at subzero temperature in soils of Arctic Alaska , 2003 .

[28]  L. Flanagan,et al.  Environmental regulation of carbon dioxide exchange at the forest floor in a boreal black spruce ecosystem , 2001 .

[29]  B. H. Honkala,et al.  Silvics of North America , 1990 .

[30]  C. W. Thornthwaite.  An Approach Toward a Rational Classification of Climate , 1948 .

[31]  J. Schimel,et al.  Microbial activity of tundra and taiga soils at sub-zero temperatures , 1995 .

[32]  M. Barreiros,et al.  The Influence of Dioxide Chloride on Water Quality of Balneário Camboriú Beach, Brazil , 2007, Environmental monitoring and assessment.

[33]  C. T. Dyrness,et al.  An overview of the vegetation and soils of the floodplain ecosystems of the Tanana River, interior Alaska , 1993 .

[34]  W. Oechel,et al.  Moss functioning in different taiga ecosystems in interior Alaska , 1981, Oecologia.

[35]  S. Gower,et al.  Belowground carbon allocation in unfertilized and fertilized red pine plantations in northern Wisconsin. , 1995, Tree physiology.

[36]  K. Nadelhoffer.  Nitrogen isotope studies in forest ecosystems. , 1994 .

[37]  Masahito Ueyama,et al.  Controlling factors on the interannual CO2 budget at a subarctic black spruce forest in interior Alaska , 2006 .

[38]  E. Kane,et al.  Controls over pathways of carbon efflux from soils along climate and black spruce productivity gradients in interior Alaska , 2006 .

[39]  A. Leahey,et al.  The Canadian System of Soil Classification and the Seventh Approximation1 , 1963 .

[40]  A. Michelsen,et al.  Respiration of Recently-Fixed Plant Carbon Dominates Mid-Winter Ecosystem CO2 Production in Sub-Arctic Heath Tundra , 2001 .

[41]  J. Subke,et al.  Trends and methodological impacts in soil CO2 efflux partitioning: A metaanalytical review , 2006 .

[42]  G. Spomer,et al.  Ecotypic variation in root respiration rate among elevational populations ofAbies lasiocarpa andPicea engelmannii , 1986, Oecologia.

[43]  R. Michener,et al.  Stable isotopes in ecology and environmental science , 1995 .

[44]  J. Waddington,et al.  Cutover peatlands: A persistent source of atmospheric CO2 , 2002 .

[45]  Susan E. Trumbore,et al.  Partitioning sources of soil respiration in boreal black spruce forest using radiocarbon , 2006 .

[46]  L. Flanagan,et al.  Measuring and modelling environmental influences on photosynthetic gas exchange in Sphagnum and Pleurozium , 1998 .

[47]  R. Ruess,et al.  Coupling fine root dynamics with ecosystem carbon cycling in black spruce forests of interior Alaska , 2003 .

[48]  M. Lavigne,et al.  Soil respiration responses to temperature are controlled more by roots than by decomposition in balsam fir ecosystems , 2003 .

[49]  F. Chapin,et al.  Temperature control over root growth and root biomass in taiga forest trees , 1983 .

[50]  E. Schuur,et al.  Soil carbon stabilization along climate and stand productivity gradients in black spruce forests of interior Alaska , 2004 .

[51]  K. Pregitzer,et al.  Latitudinal variation in sugar maple fine root respiration , 1995 .

[52]  R. K. Hermann,et al.  Standing crop, production, and turnover of fine roots on dry, moderate, and wet sites of mature Douglas-fir in western Oregon , 1985 .

[53]  A. Lindroth,et al.  CO2 exchange at the floor of a boreal forest , 2000 .

[54]  Knute J. Nadelhoffer,et al.  Belowground Carbon Allocation in Forest Ecosystems: Global Trends , 1989 .

[55]  J. Norman,et al.  Net Ecosystem Production of Two Contrasting Boreal Black Spruce Forest Communities , 2003, Ecosystems.

[56]  N. Buchmann,et al.  Large-scale forest girdling shows that current photosynthesis drives soil respiration , 2001, Nature.

[57]  Richard D. Boone,et al.  Contributions of aboveground litter, belowground litter, and root respiration to total soil respiration in a temperate mixed hardwood forest , 1993 .

[58]  J. P. Kimmins,et al.  Above- and below-ground biomass and production of lodgepole pine on sites with differing soil moisture regimes , 1989 .

[59]  Yiqi Luo,et al.  Acclimatization of soil respiration to warming in a tall grass prairie , 2001, Nature.

[60]  Charles T. Garten,et al.  Relationships between soil nitrogen dynamics and natural 15N abundance in plant foliage from Great Smoky Mountains National Park , 1994 .