Belowground structure and production in a Mediterranean sand dune shrub community
Tóm tắt
Belowground structure and annual production in an open Mediterranean scrub were studied on a sandy substrate which had not been harvested or exposed to fire during the last 30–40 years. Estimated belowground biomass (1328 ± 93.4 g m-2) and production (548 ± 246.9 g m-2 yr-1) were lower than in other Mediterranean scrubs. However, the energy investment in belowground structures was high (root biomass/ shoot biomass = 2.7; annual belowground production/ annual aboveground production = 7.1), which is associated with a high density of fine roots in the top soil (the average distance between the fine roots = 0.76 cm). A very simple model based on nutrient diffusion was considered to analyse the resource constrains of the community. The results underline the importance of nutrients (and more specifically phosphorus) rather than water, as possible determinants of the structure and dynamics of the root system, as well as for the primary production of the community during the vegetative period.
Tài liệu tham khảo
Atkinson D 1991 Plant Root Growth. An Ecological Perspective. Blackwell Scientific Publications, Oxford, UK. 347 p.
Böhm W 1979 Methods of Studying Root Systems. Springer Verlag, Berlin. 183 p.
Caldwell M M and Richards J D 1986 Competing root systems: morphology and models of absorption. In On the Economy of Plant Form and Function. Ed. T J Givnish. pp 251–273. Cambridge University Press, Cambridge.
Day J A 1983 Mineral nutrients in mediterranean ecosystems. South African National Scientific Programmes, Report 71, Pretoria.
Ellemberg H 1971 Nitrogen content, mineralization and cycling. In Productivity of Forest Ecosystems. Ed. P Duvigneaud. pp 509–514. UNESCO, Paris.
Fabiao A, Persson H A and Steen E 1985 Growth dynamics of superficial roots in Portuguese plantations of Eucalyptus globulus Labill studied with a mesh bag technique. Plant Soil 83, 233–242.
Fernández J E, Moreno F, Martín Aranda J and Fereres E 1992 Olive-tree root dynamics under different soil water regimes. Agr. Med. 122, 225–235.
Fitter H A and Strickland T R 1991 Architectural analysis of plant root systems III. Studies on plants under field conditions. New Phytol. 121, 243–248.
Gallardo A and Merino J Soil nitrogen dynamics in response to carbon increase in a mediterranean shrubland of S.W. Spain. Biogeochemistry. (In press).
González Bernáldez F, García Novo F and Ramírez Díaz L 1975 Analyse factorielle de la végétation des dunes de la Réserve Biologique de Doñana. Israel J. Bot. 24, 106–117.
Gray J T and Schlesinger W H 1981 Nutrient cycling in Mediterranean type Ecosystems. In Resource Use by Chaparral and Matorral. Ecological Studies Vol. 39. Ed. P C Miller. pp 259–285. Springer-Verlag, New York.
Hendrick R L and Pregitzer K S 1993 Patterns of fine root mortality in two sugar maple forest. Nature 361, 59–61.
Hilbert D W and Canadell J 1995 Biomass partitioning and resource allocation of plants from mediterranean-type ecosystems: possible responses to elevated CO2. In Global Change and Mediterranean-type Ecosystems. Ecological Studies, Vol. 117. Ed. J M Moreno and W C Oechel. pp 76–101. Springer-Verlag, Berlin.
Hoffman A and Kummerow J 1978 Root studies in the Chilean Matorral. Oecologia 32, 57–69.
Jackson R B and Caldwell M M 1993 Geoestatistical patterns of soil heterogeneity around individual perennial plants. J. Ecol. 81, 683–692.
Kachi N and Irose T 1983 Limiting nutrients for plants growth in coastal sand dune soils. J. Ecol. 71, 937–944.
Kummerow J 1981 Structure of roots and root systems. In Ecosystems of the World, 11. Mediterranean-type Shrublands. Eds. F di Castri, D W Goodall and R L Specht. pp 269–288. Elsevier, Amsterdam.
Kummerow J, Montenegro G and Krause J 1981 Biomass, phenology and growth. In Resource Use by Chaparral and Matorral. Ecological Studies, Vol. 39. Ed. P C Miller. pp 69–96. Springer-Verlag, New York.
Kummerow J, Kummerow M and Trabaud L 1990 Root biomass, root distribution and the fine root growth dynamics of Quercus coccifera L. in the garrigue of Southern France. Vegetatio 87, 37–44.
Larsson K and Steen E 1988 Changes in mass and chemical composition of grass roots during decomposition. Grass Forage Sci. 43, 173–177.
Margaris N S 1976 Structure and dynamics on a phryganic (East Mediterranean) ecosystem. J. Biogeog. 3, 249–259.
Mc Coy E L, Boersma L, Ungs M L and Akratanakul S 1984 Toward understanding soil water uptake by plant roots. Soil Sci. 137, 69–77.
Merino O 1988 Xylem water potential and phenological relationships in narrowleaf species growing on sand dunes in southern Spain. In Time Scales and Water Stress. Eds. F di Castri, Ch Floret, S Rambal and J Roy. pp 227–232. Proc. V Int. Conf. Mediterranean Ecosystems. I.U.B.S, Paris.
Merino J, García Novo F and Sánchez Díaz M 1976 Annual fluctuation of water potential in the xerophytic shrub of the Doñana Biological Reserve (Spain). Oecol. Plant. 11, 1–11.
Merino O, Martín M P, Martín A and Merino J 1990 Succesional and temporal changes in primary productivity in two mediterranean scrub ecosystems. Oecol. Plant. 11, 103–112.
Merino O, Villar R, Martín M, García D and Merino J 1995 Vegetation response to Climatic Change in a dune ecosystem in Southern Spain. In Global Change and Mediterranean-type Ecosystems. Ecological Studies, Vol. 117. Eds J M Moreno and W C Oechel. pp 225–238. Springer Verlag, Berlin.
Montenegro G, Anaya S, Aljaro M E and Avila G 1982 Seasonal fluctuations of vegetative growth in roots and shoots of Central Chilean shrubs. Oecologia 53, 235–237.
Mooney H A 1983 Carbon gaining capacity and allocation patterns of Mediterranean-climate plants. In Mediterranean-type ecosystems. The Role of Nutrients. Ecological Studies, Vol. 43. Eds. F J Kruger, D T Mitchel and J U M Jarvis. pp 103–119. Springer-Verlag, Berlin.
Mooney H A and Chu C 1974 Seasonal carbon allocation in Heteromeles arbutifolia, a Californian evergreen shrub. Oecologia 14, 295–306.
Nye P H and Tinker P B 1977 Solute Movement in the Soil-Root System. Blakwell Scientific Publications, Oxford, UK. 342 p.
Rodier J 1981 Análisis de las Aguas. Omega, Barcelona.
Rodríguez J B, Self J R, Soltanpour P N 1994 Optimal conditions for phosphorus analysis by the ascorbic acid molybdenum blue method. Soil Sci. Soc. Amer. J. 58, 866–870.
Sala O E, Biondini M E and Laurenroth W K 1988 Bias in estimates of primary production: An analytical solution. Ecol. Model. 44, 43–55.
Schulze E D, Kelliher F M, Körner Ch., Lloyd J and Leuning R 1994 Relationships among maximun stomatal conductance, ecosystem surface conductance, carbon assimilation rate, and plant nitrogen nutrition. Ann. Rev. Ecol. Syst. 25, 629–660.
ten Harkel M J and van der Meulen F 1995 Impact of grazing and atmospheric nitrogen deposition on the vegetation of dry coastal dune grasslands. J. Veg. Sci. 6, 445–452.
Tennant D 1975 A test of a modified line intersect method of estimating root length. J. Ecol. 64, 995–1001.
Voght A K and Persson H 1991 Meassuring growth and development of roots. In Techniques and Approaches in Forest Tree Ecophysiology. Eds. J P Lassoie and T M Hincley. pp 477–501. CRS, Press.
Westman W E 1983 Plant community structure-spatial partitioning of resources. In Mediterranean-type Ecosystems. The Role of nutrients. Ecological Studies, Vol. 43. Eds F J Kruger, D T Mitchell, and J U M Jarvis. pp 417–445. Springer-Verlag, Berlin.