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Biogeochemistry

, Volume 15, Issue 3, pp 175–190 | Cite as

Root turnover as determinant of the cycling of C, N, and P in a dry heathland ecosystem

  • R. Aerts
  • C. Bakker
  • H. De Caluwe
Article

Abstract

Root production and turnover were studied using sequential core sampling and observations in permanent minirhizotrons in the field in three dry heathland stands dominated by the evergreen dwarfshrub Calluna vulgaris and the grasses Deschampsia flexuosa and Molinia caerulea, respectively. Root biomass production, estimated by core sampling, amounted to 160 (Calluna), 180 (Deschampsia) and 1380 (Molinia) g m-2 yr-1, respectively. Root biomass turnover rate in Calluna (0.64 yr-1) was lower compared with the grasses (Deschampsia: 0.96 yr-1; Molinia 1.68yr-1)). Root length turnover rate was 0.75–0.77 yr-1 (Deschampsia) and 1.17–1.49 yr-1 (Molinia), respectively. No resorption of N and P from senescing roots was observed in either species. Input of organic N into the soil due to root turnover, estimated using the core sampling data, amounted to 1.8 g N m-2 yr-1(Calluna), 1.7 g N m-2 yr-1 (Deschampsia) and 19.7 g N m-2 yr-1 (Molinia), respectively. The organic P input was 0.05, 0.07 and 0.55 g P M-2 yr-1, respectively. Using the minirhizotron turnover estimates these values were20–22% (Deschampsia) and 11–30% (Molinia) lower.

When the biomass turnover data were used, it appeared that in the Molinia stand root turnover contributed 67% to total litter production, 87% to total litter nitrogen loss and 84% to total litter phosphorus loss. For Calluna and Deschampsia these percentages were about three and two times lower, respectively.

This study shows that (1) Root turnover is a key factor in ecosystem C, N, and P cycling; and that (2) The relative importance of root turnover differs between species.

Key words

carbon cycling heathland minirhizotron N and P cycling N and P resorption root turnover 

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References

  1. Aber JD, Melillo JM, Nadelhoffer KJ, McClaugherty CA & Pastor J (1985) Fine root turnover in forest ecosystems in relation to quantity and form of nitrogen availability: a comparison of two methods. Oecologia 66: 317–321Google Scholar
  2. Aerts R (1989) Aboveground biomass and nutrient dynamics of Calluna vulgaris and Molinia caerulea in a dry heathland. Oikos 56: 31–38Google Scholar
  3. Aerts R (1990) Nutrient use efficiency in evergreen and deciduous species from heathlands. Oecologia 84: 391–397Google Scholar
  4. Aerts R, Berendse F, Klerk NM & Bakker C (1989) Root production and root turnover in two dominant species of wet heathlands. Oecologia 81: 374–378Google Scholar
  5. Aerts R, Berendse F, De Caluwe H & Schmitz M (1990) Competition in heathland along an experimental gradient of nutrient availability. Oikos 57: 310–318Google Scholar
  6. Berendse F, Beltman B, Bobbink R, Kwant R & Schmitz M (1987) Primary production and nutrient availability in wet heathland ecosystems. Acta Oecol. /Oecol. Plant. 8 (22): 265–279Google Scholar
  7. Berendse F, Bobbink R & Rouwenhorst G (1989) A comparative study on nutrient cycling in wet heathland ecosystems II. Litter decomposition and nutrient mineralization. Oecologia 78: 338–348Google Scholar
  8. Böhm W (1979) Methods of studying root systems. Springer-Verlag, BerlinGoogle Scholar
  9. Caldwell MM (1979) Root structure: the considerable cost of belowground function. In: Solbrig OT, Jain S, Johnson GB & Raven PH (Eds) Topics in plant population biology (pp 408–427). Columbia University Press, New YorkGoogle Scholar
  10. Chapman SB (1979) Some interrelationships between soil and root respiration in lowland Calluna heathland in southern England. J. Ecol. 67: 1–20Google Scholar
  11. Cheng W, Coleman DC & Box JE Jr. (1990) Root dynamics, production and distribution in agroecosystems on the Georgia Piedmont using minirhizotrons. J. Appl. Ecol. 27: 592–604Google Scholar
  12. Chapin FS (1980) The mineral nutrition of wild plants. Ann. Rev. Ecol. Syst. 11: 233–260Google Scholar
  13. De Smidt JT (1977) Heathland vegetation in the Netherlands. Phytocoenologia 4: 258–316Google Scholar
  14. Forrest GI (1971) Structure and production of North Pennine blanket bog vegetation. J. Ecol. 59: 453–479Google Scholar
  15. French DD (1988) Some effects of changing soil chemistry on decomposition of plant litters and cellulose on a Scottish moor. Oecologia 75: 608–618Google Scholar
  16. Frissel MJ (1981) The definition of residence time in ecological models. In: Clark FE & Rosswall T (Eds) Terrestrial Nitrogen Cycles (pp 117–122). Ecol. Bull. (Stockholm) 33Google Scholar
  17. Grime JP (1979) Plant strategies and vegetation processes. John Wiley and Sons, New YorkGoogle Scholar
  18. Kubiena WL (1953). The soils of Europe. Murby, LondonGoogle Scholar
  19. McClaugherty CA, Aber JD & Melillo JM (1982) The role of fine roots in the organic matter and nitrogen budgets of two forested ecosystems. Ecology 63: 1481–1490Google Scholar
  20. Persson H (1978) Root dynamics in a young Scots pine stand in Central Sweden. Oikos 30: 508–519Google Scholar
  21. Persson H (1979) Fine-root production, mortality and decomposition in forest ecosystems. Vegetatio 41: 101–109Google Scholar
  22. Raich JW & Nadelholffer KJ (1989) Belowground carbon allocation in forest ecosystems: global trends. Ecology 70: 1346–1354Google Scholar
  23. Robinson D & Rorison IH (1983) A comparison of the responses of Lolium perenne L., Holcus lanatus L. and Deschampsia flexuosa (L.) Trin. to a localized supply of nitrogen. New Phytol. 94: 263–273Google Scholar
  24. Robinson D & Rorison IH (1988) Plasticity in grass species in relation to nitrogen supply. Funct. Ecol. 2: 249–257Google Scholar
  25. SAS Institut Inc. (1985) SAS/STAT Guide for personal computers, Version 6 edition. Cary, N.C.Google Scholar
  26. Singh JS, Lauenroth WK, Hunt HW & Swift DM (1984) Bias and random errors in estimates of net root production: a simulation approach. Ecology 65: 1760–1764Google Scholar
  27. Taylor HM (1987) Minirhizotron observation tubes: Methods and applications for measuring rhizosphere dynamics. ASA Special Publication 50. ASA/CSSA/SSSA, Madison, 143 ppGoogle Scholar
  28. Tennant D (1975) A test of a modified line intersect method of estimating root length. J. Ecol. 63: 995–1001Google Scholar
  29. Tinhout A & Werger MJA (1988) Fine roots in a dry Calluna heathland. Acta Bot. Neerl. 37: 225–230Google Scholar
  30. Vogt KA & Bloomfield J (1991) Tree root turnover and senescence. In: Waisel Y, Eschel A & Kafkafi U (Eds) Plant roots, the hidden half (pp 287–306). Marcel Dekker Inc, New YorkGoogle Scholar
  31. Vogt KA, Grier CC, Vogt DJ (1986) Production, turnover, and nutrient dynamics of above-and belowground detritus of world forests. Adv. Ecol. Res. 15: 303–377Google Scholar
  32. Vogt KA, Grier CC, Meier CE & Keyes MR (1983) Organic matter and nutrient dynamics in forest floors of young and mature Abies amabilis stands in western Washington, as affected by fine root input. Ecological Monographs 53: 139–157Google Scholar
  33. Vos J & Groenwold J (1983) Estimation of root densities by observation tubes and endoscope. Plant Soil 74: 295–300Google Scholar

Copyright information

© Kluwer Academic Publishers 1992

Authors and Affiliations

  • R. Aerts
    • 1
  • C. Bakker
    • 1
  • H. De Caluwe
    • 1
  1. 1.Dept of Plant Ecology and Evolutionary BiologyUniversity of UtrechtTB UtrechtThe Netherlands

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