Abstract
During three consecutive years with contrasting precipitation, we analysed the relationship between strategies of N conservation in the dominant plant functional groups (perennial grasses and evergreen shrubs) of the Patagonian Monte and the main components of N cycling in soil. We hypothesised that the different patterns of N conservation in perennial grasses and evergreen shrubs would have direct consequences for soil-N, inorganic-N release and microbial-N flush in soil. In autumn and late spring of 1999, 2000, and 2001, we assessed N and C concentration in green and senesced leaves, N-resorption efficiency and C/N ratio in senesced leaves of three dominant species of each plant functional group. In the soil associated with species of each plant functional group, we determined N and C concentration, potential-N mineralisation, and the associated microbial-N flush. Slow-growing evergreen shrubs exhibited low N-concentration in green leaves, high N-concentration in senesced leaves and low N-resorption from senescing leaves. In contrast, fast-growing perennial grasses showed high N-concentration in green leaves, low N-concentration in senesced leaves, and high N-resorption from senescing leaves. In evergreen shrubs, the maintenance of long-lasting green leaves with low N-concentration was the most important mechanism of N conservation. In contrast, perennial grasses conserved N through high N-resorption from senescing leaves. Soil-N concentration, potential N-mineralisation, and microbial-N flush in the soil were higher underneath evergreen shrubs than beneath perennial grasses. Observed differences, however, were lower than expected considering the quality of the organic matter supplied by each plant fuctional group to the soil. A possible reason for this relatively weak trend may be the capacity of evergreen shrubs to slow down N cycling through low leaf turnover and the presence of secondary compounds in leaves. Alternatively or simultaneously, the weak relationship between plant and soil N could result from shrubs being able to colonise N-poor soils while grasses may preferably occupy fertile microsites previously influenced by the decomposition pathway of evergreen shrubs. Differences between evergreen shrubs and perennial grasses in the mechanisms of plant N-conservation and in components of N cycling in the underlying soil were consistent over the three years of the study with differing precipitation. Inter-annual differences in N concentration in green leaves and in the microbial-N flush in soil indicate that during the wettest year fast-growing perennial grasses would outcompete slow-growing evergreen shrubs and microorganisms for N uptake.
Similar content being viewed by others
References
Aerts R 1996 Nutrient resorption from senescing leaves of perennials: are there general patterns? J. Ecol. 84, 597–608.
Aerts R 1999 Interspecific competition in natural plant communities: mechanisms, trade-offs and plant-soil feedbacks. J. Exp. Bot. 330, 29–37.
Aerts R and F S Chapin III 2000 The mineral nutrition of wild plants revisited: a re-evaluation of processes and patterns. Adv. Ecol. Res. 30, 1–67.
Aerts R and Van der Peijl M J 1993 A simple model to explain the dominance of low-productive perennials in nutrient-poor habitats. Oikos 66, 144–147.
Bernhard-Reversat F 1982 Biochemical cycle of nitrogen in a semiarid savanna. Oikos 38, 321–332.
Bertiller M B 1998 Spatial patterns of the germinable soil seed bank in northern Patagonia. Seed Sci. Res. 8, 39–45.
Bertiller M B, Beeskow A M and Coronato F 1991 Seasonal environmental and plant phenology in arid Patagonia (Argentina). J. Arid Environ. 21, 1–11.
Bertiller M B and Bisigato A J 1998 Vegetation dynamics under grazing disturbance. The state-and-transition model for the Patagonian steppes. Ecol. Aust. 8, 191–199.
Bertiller M B, Sain C L, Bisigato A J, Coronato F R, Ares J O and Graff P 2002. Spatial sex segregation in the dioecious grass Poa ligularis in northern Patagonia: the role of environmental patchiness. Biodivers. Conserv. 11, 69–84.
Binkley D 1994 The influence of tree species on forest soils. Processes and Patterns. In Trees and Soil Workshop Proceedings. Eds. D Mead and G Will. pp. 1–24. Lincoln Univ., New Zealand.
Bisigato A J and Bertiller M B 1997 Grazing effects on patchy dryland vegetation in northern Patagonia. J. Arid Environ. 36, 639–653.
Bisigato A J and Bertiller M B 1999 Seedling emergence and survival in contrasting soil microsites in Patagonian Monte shrubland. J. Veg. Sci. 10, 335–342.
Bloemhof H S and Berendse F 1995 Simulation of the decomposition and nitrogen mineralization of aboveground plant material in two unfertilized grassland ecosystems. Plant Soil 177, 157–173.
Bremmer J M and C S Mulvaney 1982 Regular Kjeldahl method. In Methods of Soil Analysis – Chemical and Microbiological Propierties. Serie Agronomy No. 9. Eds. A L Page, R H Miller and D R Keeney. pp. 595–624. Wisconsin, USA.
Cabrera A L 1976 Las Regiones Fitogeográficas Argentinas. Enciclopedia Argentina de Agricultura, Jardinería y Horticultura. ACME. Bs As, Arg.
Carrera A L, Sain C L and Bertiller M B 2000 Patterns of nitrogen conservation in shrubs and grasses in the Patagonian Monte, Argentina. Plant Soil 224, 185–193.
Chapin F S III and Kedrowski R A 1983 Seasonal changes in nitrogen and phosphorus fractions and autumn retraslocation in evergreen and deciduous taiga trees. Ecology 64, 376–391.
Coombs J, Hind G, Leegood R C, Tieszen L and Vonshsk A 1985 Analytical techniques. In Techniques in Bioproductivity and Photosyntesis. Eds. J Coombs, D O Hall, S Long and J M Scurlock. pp. 219–228. Pergamon Press, Oxford.
Correa M N 1971 Flora patagónica, parte VII. Colección Científica tomo VIII. Instituto Nacional de Tecnología Agropecuaria (INTA), Buenos Aires. 451 pp.
Crawley M J 1998 Life history and environments. In Plant Ecology. Ed. M J Crawley. pp. 73–131. Blackwell Science, Oxford.
Defossé G E, Bertiller M B and Ares J O 1990 Above-ground phytomass dynamics in grassland steppe of Patagonia, Argentina. J. Range Manage. 43, 157–160.
del Valle H F 1998 Patagonian soils: a regional synthesis. Ecol. Aust. 8, 103–123.
del Valle H F and Rosell R A 1999 Mineral composition of perennial vegetation of shrubs patches in northeastern Patagonia. Arid Soil Res. Rehab. 13, 24–35.
Eckstein R L, Karlsson P S and Weih M 1998 The significance of sorption of leaf resources for shoot growth in evergreen and deciduous woody plants from a subartics environment. Oikos 81, 567–575.
Garcia-Moya E and McKell C M 1970 Contribution of shrubs to the nitrogen economy of desert-wash plant community. Ecology 51, 81–88.
Garnier E 1998 Interspecific variation in plasticity of grasses in response to nitrogen supply. In Population Biology of Grasses. Ed. G P Garnier. pp. 155–182. Cambridge University Press, New York.
Harbone J B 1998 Plant Secondary Metabolism. In Plant Ecology. Ed. M J Crawley. pp. 132–155. Blackwell Science, Oxford.
Hooper D U and Vitousek P M 1998 Effects of plant composition and diversity on nutrient cycling. Ecol. Monogr. 68, 121–149.
Horwarth W R and Paul E A 1994 Microbial biomass. In Methods of Soil Analysis 2. Microbiological and Biochemical Properties. Eds. R A Weaver, S Angle, P Bottomley, D Bezdicek, S Smith, A Tabatal and A Wollum. pp. 753–773. Soil Science Society of America, Madison, Wisc.
Ihori T, Burke I C and Hook P B 1995 Nitrogen mineralization in native cultivated and abandoned fields in shortgrass steppe. Plant Soil. 171, 203–208.
Keeney D R and Nelson D W 1982 Nitrogen-Inorganic forms. In Methods of Soil Analysis – Chemical and Microbiological Propierties. Serie Agronomy No. 9. Eds. A L Page, R H Miller and D R Keeney. pp. 643–698. Wisconsin, USA.
Killingbeck K T 1996 Nutrients in senescent leaves: keys to the search for potential resorption and resorption proficiency. Ecology 77, 1716–1727.
Lambers H, Chapin F S III and Pons T 1998 Mineral nutrition In Plant Physiological Ecology. Eds. H Lambers, F S Chapin III and T Pons. pp 239–298. Springer Verlag, New York.
Martin M E and Aber J D 1997 High spectral resolution remote sensing of forest canopy lignin, nitrogen, and ecosystem processes. J. Ecol. Appl. 7, 431–443.
Mazzarino M J and Bertiller M B 1999 Soil N pool and processes as indicators of desertification in semi-arid woodlands and semiarid to arid steppes of Argentina. VIth Int. Rangeland Congr. Proc. 1, 101–105.
Mazzarino M J, Bertiller M B, Sain C L, Laos F and Coronato F R 1996 Spatial patterns of nitrogen availability, mineralization, and immobilization in northern Patagonia, Argentina. Arid Soil Res. Rehab. 10, 295–309.
Mazzarino M J, Bertiller M B, Sain C L, Satti P and Coronato F R 1998a Soil nitrogen dynamics in northeastern Patagonia steppe under different precipitation regimes. Plant Soil 202, 125–131.
Mazzarino M J, Bertiller M B, Schlichter T and Gobbi M 1998b Nutrient cycling in Patagonian ecosystems. Ecol. Aust. 8, 167–182.
Mazzarino M J, Oliva L, Núñez A, Núñez G and Bufa E 1991 Factors affecting N dynamics in semiarid woodland (Dry Chaco, Argentina). Plant Soil 138, 85–98.
Nelson D W and Sommers L E 1982 Total carbon, organic carbon, and organic matter. In Methods of Soil Analysis – Chemical and Microbiological Propierties. Serie Agronomy No. 9. Eds. A L Page, R H Miller and D R Keeney. pp. 539–579. Wisconsin, USA.
Norusis M J 1997 SPSS Advanced statistics 7.5. SPSS, Chicago. 579 pp.
Rostagno C M, del Valle H F and Videla L S 1991 The influence of shrubs on some chemical and physical properties of an aridic soil in north-eastern Patagonia, Argentina. J. Arid Environ. 20, 179–188.
Sala O E, Golluscio R A, Lauenroth W K and Soriano A 1989 Resource partitioning between shrubs and grasses in the Patagonian steppe. Oecologia 81, 501–505.
Schlesinger W H 1991 Biogeochemistry: An Analysis of Global Change. Academic Press, San Diego, CA.
Schlesinger W H and Hasey M M1981 Descomposition of chaparral shrubs foliage: losses of organic and inorganic constituents from deciduous and evergreen leaves. Ecology 62, 762–774.
Skujins J 1981 Nitrogen cycling in arid ecosystems. In Terrestrial Nitrogen Cycles. Eds. F E Clark and T Rosswall. Swedish Natural Science Research Council, Stockholm. Ecol. Bull. 33, 477–491.
Soil Survey Staff 1998 Keys to Soil Taxonomy. USDA, Washington, DC. 326 pp.
Sokal R R and Rohlf F J 1981 Biometry. Freeman, San Francisco, C A.
Soriano A 1950 La vegetación del Chubut. Rev. Arg. Agr. 17, 30–66.
Vinton M A and Burke I C 1995 Interaction between individual plant species and soil nutrient status in Shortgrass steppe. Ecology. 76, 1116–1133.
Vitousek P M and Matson P A 1985 Disturbance, N availability and N losses: an experimental study in an intensively managed loblolly pine plantation. Ecology 66, 1360–1376.
Vitousek P M, Gosz J R, Grier C C, Melillo J M and Reiners W A 1982 A comparative analysis of potential nitrification and nitrate mobility in forest ecosystems. Ecol. Monogr. 52, 155–177.
Wedin D A and Tilman D 1990 Species effect on nitrogen cycling: a test with perennial grasses. Oecologia 84, 433–441.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Carrera, A.L., Bertiller, M.B., Sain, C.L. et al. Relationship between plant nitrogen conservation strategies and the dynamics of soil nitrogen in the arid Patagonian Monte, Argentina. Plant and Soil 255, 595–604 (2003). https://doi.org/10.1023/A:1026087419155
Issue Date:
DOI: https://doi.org/10.1023/A:1026087419155