Root turnover in a beech and a spruce stand of the Belgian Ardennes
The theoretical basis of fine root turnover estimation in forest soils is discussed, in relation to appropriate experimental techniques of measurement. After sequential coring, the correct expression is the sum of significant positive increments of live and dead roots of the various diameter categories, to which the transfer of dead roots to organic matter derived from roots, OMDR, has to be added. This should not be confounded with dead root mineralization. The transfer rates should first be estimated in root dimensions and not in weight of dry matter.
The measurements were carried out in a 120 year old beech (Fagus sylvatica L.) stand and a 35 year old Norway spruce (Picea abies Karst) stand, in the Eastern Ardennes, Belgium.
The turnover rate of fine roots (diam. <5 mm) was 4393 kg ha−1 year−1 (root dry weight), including 711.2 kg ha−1 year−1 for dead root transfer to OMDR, for beech.
For spruce, turnover rate was 7011 kg ha−1 year−1 (root dry weight), including 1498 kg ha−1 year−1 for dead root transfer to OMDR.
Under beech, there was a slight root density increase in spring. No seasonal fluctuations were observed under spruce, but a strong irreversible drop in live root growth was found in the later season 1980–1981, corresponding to a decrease of tree height growth and trunk radius increment.
Turnover rates were further expressed in dry weight and in amounts of elements (kg ha−1 year−1) (Ca, Mg, K, Na, Al, N, P, S).
Correlative relations between root dimensions and dry weight and element concentrations show that the derived values, and in particular root specific density (dry weight volume−1) vary according to species, root category, and seasonal sampling.
Various schemes of seasonal variations of root growth, described in Europe, show that the major dependance on general climate is obscured by environmental factors (soil, exposure, species). It is suggested that root density fluctuation approach the steady state on an annual basis under mild Atlantic conditions.
Key wordsFagus silvativa fine roots Picea abies root density
Unable to display preview. Download preview PDF.
- Ågren G I, Axelsson B, Flower-Ellis J G K, Linder S, Persson H and Staaf H 1980 Annual carbon budget for a young Scots pine.In Structure and Function of Northern Coniferous Forests—An Ecosystem Study. Ecol. Bull. (Stockholm) 32, 307–313.Google Scholar
- Baldwin J P, Tinker P B and Mariott F H P 1971 The measurements of length and distribution of onion roots in the field and the laboratory. J. App. Ecol. 8, 543–554.Google Scholar
- Bohm W 1979 Methods of studying root systems. Ecological Studies 3, Springer-Verlag, Berlin.Google Scholar
- Bowen G D 1969 The uptake of orthophosphate and its incorporation into organic phosphates along roots of pinus radiata. Aust. J. Biol. Sci. 22, 1125–35.Google Scholar
- Bowman K O and Shenton L R 1975 Omnibus test contours for departure from normality based on 101-1, and b2. Biometrica 62, 2, 243–249.Google Scholar
- Dagnelie P 1973 Théorie et méthodes statistiques. Presses Agronomiques de Gembloux. Ed. Belgium. 3 vol.Google Scholar
- Fairley R I and Alexander I J 1982 Seasonal dynamics of fine roots and mycorrhizas in a sitka spruce plantation. Abstracts. Conf. Tree root system and their mycorrhizas. I.U.F.R.O. Edinburgh and Canterbury.Google Scholar
- Fogel R 1980 Mycorrhizae and nutrient cycling in natural forest ecosystems. New Phytol. 86, 199–212.Google Scholar
- Grier G C, Vogt K A, Keyes M R and Edmonds R L 1981 Biomass distribution and above-and-below-ground production in young and mature Abies amabilis zone ecosystems of the Washington Cascades. Can. J. For. Res. 11, 155–167Google Scholar
- Harris W F, Kinerson R S and Edwards N T 1977 Comparison of below ground biomass of natural deciduous forest and loblolly pine plantations. Pedobiologica. 17, 369–381.Google Scholar
- Jenkinson D S 1977 Studies on the decomposition of plant material in soil: 5. The effect of plant cover and soil type on the loss of carbon from14C labelled ryegrass decomposing under field conditions. J. Soil. Sci. 28, 424–434.Google Scholar
- Joslin J D 1983 The Quantification of Fine Root Turnover in a White Oak Stand. Thesis. Univ. Missouri. Columbia. Ann. Arbor. Univ. Microfilms. Inter 84—062.10.Google Scholar
- Kalela E K 1957 Uber Veränderungen in den Wurzelverhältnissen der Kifernbeständer in Laufe der vegetationsperiode. Acta Forestalia Fennica 65, 5–42.Google Scholar
- Kottke I 1986 Wurzelentwichlung und Wachstum der Fichte (Picea abies (L) H Karsten) auf interschiedlichen Böden und künstlichen substraten.In Das landschafts-ökologische Forschungprojekt Naturpark Schönbuck DFG. Ed. G Einsele.Google Scholar
- Kramer P S and Bullock H C 1966 Seasonal variations in the proportions of suberized and insuberized roots of trees in relation to the absorption of water. Amer. J. Bot. 52, 200–204.Google Scholar
- Manil L, Ledant J P, van Praag H J and Manil G 1977 Distribution des Racines Fines dans les Sites Forestiers de Mirwart. dans Productivité Biologique en Belgique. Ed. P Duvigneaud et P Kestemont. Imp. Duculot. Gembloux, Belgique.Google Scholar
- McClaugherty C A, Aber J D and Melillo J M 1982 The role of fine roots in the organic matter and nitrogen budgets of two forested ecosystems. Ecology 63, 1981–1990.Google Scholar
- Ovington J D, Heitkamp D and Lawrence D B 1963 Plant biomass and productivity of prairie, savanna, oakwood and maize field ecosystems in Central Minnesota. Ecology 44, 52–63.Google Scholar
- Persson H 1978 Root dynamics in a young Scots pine stand in Central Sweden. Oikos 30, 508–519.Google Scholar
- Persson H 1980 Death and replacement of fine root in a mature Scots pine stand.In Structure and Function of Northern Coniferous Forests. An Ecosystem Study. Ecol. Bull. (Stockholm) 32, 252–260.Google Scholar
- Santantonio D 1979 Seasonal dynamics of fine roots in mature stands of Douglas—Fir of different water regimes. A preliminary report.In Physiologie des racines et symbiose. Eds. A Riedacker and J Gagnaire-Michard. pp 190–203. C.R. Réunion du groupe d'étude des racines. Nancy-France.Google Scholar
- Schumacker R 1985 Originalité de la flore et de la végétation du nord du Massif Ardennais. Publication “Les amis de la Fagne”, 180, 93–95. Verviers, Belgium.Google Scholar
- Shapiro S S and Vilk M B 1965 An analysis of variance test for normality (complete samples). Biometrica 52, 591–611.Google Scholar
- van Praag H J and Weissen F 1985 Aluminium effects on spruce and beech seedlings. Plant and Soil 83, 331–356.Google Scholar
- Vogt K A, Edmonds R L, Grier C C and Piper S R 1980 Seasonal changes in mycorrhizal and fibrous-textured root biomass in 23 and 180 years old Pacific silverfic stands in Western Washington. Can. J. For. Res. 10, 523–529.Google Scholar
- Vogt K A, Edmonds R L and Grier C C 1981 Seasonal changes in biomass and vertical distribution of mycorrhizal and fibrous-textured conifer fine roots in 23 and 180 years old subalpineAbies amabilis stands. Can. J. For. Res. 11, 223–229.Google Scholar
- Weissen F 1977 Dix années d'évolution d'une deuxième génération d'épicéas fertilisés à la plantation. I, II. Bull. Rech. Agron. Gembloux. 12 (1–2), 135–172.Google Scholar