Abstract
We have studied the underlying factors responsible for the heterogeneous ecophysiological status of a semiarid Stipa tenacissima L. steppe in a subcatchment of SE Spain by assessing population composition and habitat structure of S. tenacissima stands. To do this, we measured and estimated 18 variables (11 biotic and seven abiotic) in 15 plots randomly distributed in the subcatchment, and then zoned this area by plot affinity using PCA. This analysis produced three sectors determined mainly by S. tenacissima cover and soil depth variables. The linear relationship fitted between S. tenacissima tussock biomass and tussock density in monospecific stands (both logarithmic) indicated a curve close to −1, suggesting that the system is close to the maximum constant yield state. Ecophysiological measurements (gas exchange, fluorescence and individual leaf area index) were taken in two periods with different water availability in a representative plot in each sector. The intraspecific competition (inferred from the density dependence of green biomass) and rock outcrops were the main factors influencing the ecophysiological status in the study area. While, in the wet season, intraspecific competition regulated water consumption in zones where S. tenacissima tussocks (monospecific stands) are dominant, during the dry season, stands in zones with extensive rock outcrops and stone cover (tussocks in “soil pockets”) had no access to non-rainfall water gains because of the adjacent bare soil, and so in these stands, gas exchange was lower and photoinhibition higher. This article stresses the importance of considering the connection between tussocks and bare-ground interspace in the functional and structural analysis of semiarid steppes.
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References
Armas C (2003) Balance de la interacción entre plantas superiores en ambientes semiáridos: mecanismos y procesos. PhD thesis, Universidad Autónoma de Madrid, Spain.
Armas C, Pugnaire FI (2005) Plant interactions govern populations dynamics in a semi-arid plant community. J Ecol 93:978–989. doi:10.1111/j.1365-2745.2005.01033.x
Balaguer L, Pugnaire FI, Martinez-Ferri E, Armas C, Valladares F, Manrique E (2002) Ecophysiological significance of chlorophyll loss and reduced photochemical efficiency under extreme aridity in Stipa tenacissima L. Plant Soil 240:343–352. doi:10.1023/A:1015745118689
Bertiller MB, Zaixso P, Irisarri MP, Brevedan ER (1996) The establishment of Festuca pallescens in arid grasslands in Patagonia (Argentina): the effect of soil water stress. J Arid Environ 32(2):161–171. doi:10.1006/jare.1996.0014
Bonet A (2004) Secondary succession of semi-arid Mediterranean old-fields in south-eastern Spain: insights for conservation and restoration of degraded lands. J Arid Environ 56:213–233. doi:10.1016/S0140-1963(03)00048-X
Chirino E (2003) Influencia de las precipitaciones y de la cubierta vegetal en el balance hídrico superficial y en la recarga de acuíferos en clima semiárido. PhD thesis, University of Alicante, Spain
de Kroon H, Kalliola R (1995) Shoot dynamics of the giant grass Gynerium sagittatum in Peruviam Amazon floodplains, a clonal plant that does show self-thinning. Oecologia 101:124–131. doi:10.1007/BF00328909
Domingo F, Gutiérrez L, Brenner AJ, Aguilera C (2002) Limitation to carbon assimilation of two perennial species in semi-arid south east Spain. Biol Plant 45(2):213–220. doi:10.1023/A:1015136421445
Ferrer-Castán D, Calvo JF, Esteve-Selma MA, Torres-Martínez A, Ramírez-Díaz L (1995) On the use of three performance measures for fitting species responses curves. J Veg Sci 6:57–62. doi:10.2307/3236256
Gasque M (1999) Colonización del esparto (Stipa tenacissima L.) en sectores degradadas del clima semiárido. PhD thesis, Universidad Politécnica de Valencia, Escuela Técnica Superior de Ingenieros Agrónomos, Spain
Genty B, Briantais JM, Baker NR (1989) The relationship between the quantum yield of photosynthetic electron transport and quenching of chlorophyll fluorescence. Biochim Biophys Acta 99:87–92
Guijarro JA (1981) Aproximación al clima de Alicante y su comarca. In: Excmo. Ayuntamiento de Alicante, (ed) El medio físico de la comarca de Alicante, Ayuntamiento de Alicante, Spain, pp 248–277
Haase P, Pugnaire FI, Clark SC, Incoll L (1999) Environmental control of canopy dynamics and photosynthetic rate in the evergreen tussock grass Stipa tenacissima. Plant Ecol 145:327–339. doi:10.1023/A:1009892204336
Harper JL (1977) Population biology of plants. Academic Press Inc., San Diego, CA, pp 857
Ivans CY, Leffler AJ, Spaulding U, Stark JM, Ryel RJ, Caldwell MM (2003) Root responses and nitrogen acquisition by Artemisia tridentate and Agropyron desetorum following small summer rainfall events. Oecologia 134:317–324
Kays S, Harper JL (1974) The regulation of plant and tiller density in a grass Sward. J Ecol 62(1):97–105. doi:10.2307/2258882
Kira T, Ogawa H, Shinozaki N (1953) Intraspecific competition among higher plants. 1. Competition-density-yield inter-relationship in regularly dispersed populations. J Inst Polytech Osaka Univ Ser D 4:1–16
Kurc S, Small EE (2004) Dynamics of evapotranspiration in semiarid grassland and shrubland ecosystems during the summer monsoon season, central New Mexico. Water Resour Res 40:1–15. doi:10.1029/2004WR003068
Lázaro R, Rodrigo FS, Gutiérrez L, Domingo F, Puigdefábregas J (2001) Analysis of a 30-year rainfall record (1967–1997) in semi-arid SE Spain for implications on vegetation. J Arid Environ 48:373–395. doi:10.1006/jare.2000.0755
Le Houérou HN (2001) Biogeography of the arid steppeland north of the Sahara. J Arid Environ 48:103–128. doi:10.1006/jare.2000.0679
Lonsdale WM, Watkinson AR (1982) Light and self-thinning. New Phytol 90:431–445. doi:10.1111/j.1469-8137.1982.tb04476.x
Lonsdale WM, Watkinson AR (1983) Tiller dynamic and self-thinning in grassland habitats. Oecologia 60(3):390–395. doi:10.1007/BF00376857
Maestre FT (2006) Linking the spatial patterns of organisms and abiotic factor to ecosystems function and management: insights from semi-arid environments. Web Ecol 6:75–87
Maestre FT, Cortina J (2004a) Do positive interactions increase with abiotic stress? A test from a semi-arid steppe. Proc R Soc Lond B Biol Sci 271:S331–S333. doi:10.1098/rsbl.2004.0181
Maestre FT, Cortina J (2004b) Insights into ecosystem composition and function in a sequence of degraded semiarid steppes. Restor Ecol 12(4):493–501. doi:10.1111/j.1061-2971.2004.03106.x
Maestre FT, Cortina J (2006) Ecosystem structure and soil-surface condition drive the variability in the foliar δ13C and δ15N of Stipa tenacissima in semiarid Mediterranean steppes. Ecol Res 21:44–53. doi:10.1007/s11284-005-0091-4
Maestre FT, Bautista S, Cortina J (2003) Positive, negative, and net effects in grass-shrub interactions in Mediterranean semiarid grasslands. Ecology 84(12):3186–3197. doi:10.1890/02-0635
Mateo G, Crespo MB (2001) Manual para la determinación de la flora valenciana, 2nd edn. Moliner 40-Gómez Coll S. L., Valencia-Spain, pp 503
Puigdefábregas J, Sánchez G (1996) Geomorphological implications of vegetation patchiness on semi-arid slopes. In: Anderson MG, Brooks SM (eds) Advances in hillslopess processes, vol 2. John Wiley, New York, pp 1027–1060
Puigdefábregas J, Sole A, Guitierrez L, del Barrio G, Boer M (1999) Scales and processes of water and sediment redistribution in drylands: results from the Rambla Honda field site in Southeast Spain. Earth Sci Rev 48:39–70. doi:10.1016/S0012-8252(99)00046-X
Pugnaire FI, Haase P (1996) Comparative physiology and growth of two perennial tussock grass species in a semi-arid environment. Ann Bot (Lond) 77:81–86. doi:10.1006/anbo.1996.0010
Pugnaire FI, Haase P, Incoll L, Clark SC (1996) Response of tussock grass Stipa tenacissima to watering in a semi-arid environment. Funct Ecol 10:265–274. doi:10.2307/2389852
Ramírez DA (2006) Estudio de la transpiración del esparto (Stipa tenacissima L.) en una cuenca del semiárido alicantino: un análisis pluriescalar. PhD thesis, University of Alicante, Spain
Ramírez DA, Valladares F, Blasco F, Bellot A (2006) Assessing transpiration in the tussock grass Stipa tenacissima L.: the crucial role of the interplay between morphology and physiology. Acta Oecol 30(3):386–398. doi:10.1016/j.actao.2006.06.006
Ramírez DA, Bellot J, Domingo F, Blasco A (2007) Can water responses in Stipa tenacissima L. during the summer season be promoted by non-rainfall water gains in soil? Plant Soil 291:67–79. doi:10.1007/s11104-006-9175-3
Raventós J, Silva JF (1995) Competition effects and responses to variable numbers of neighbors in two tropical savanna grasses in Venezuela. J Trop Ecol 11(1):39–52
Reynolds JF, Kemp PR, Ogle K, Fernandez RJ (2004) Modifying the “pulse reserve” paradigm for deserts of North America: precipitation pulses, soil water and plant responses. Oecologia 141:194–210. doi:10.1007/s00442-004-1524-4
Sackville Hamilton NR, Matthew C, Lemaire G (1995) In defence of the −3/2 boundary rule: a re-evaluation of self-thinning concepts and status. Ann Bot (Lond) 76:569–577. doi:10.1006/anbo.1995.1134
Sánchez G, Puigdefábregas J (1994) Interactions of plant growth and sediment movement on slopes in a semi-arid environment. Geomorphology 9:243–260. doi:10.1016/0169-555X(94)90066-3
Servicio del Esparto (1953) Estudios y Experiencias sobre el Esparto, vol II. Ministerios de Industria y Comercio y de Agricultura, Madrid
Sher AA, Goldberg DE, Novoplansky A (2004) The effect of mean and variance in resource supply on survival of annual from Mediterranean and desert environments. Oecologia 141:353–362. doi:10.1007/s00442-003-1435-9
Schwinning S, Sala OE (2004) Hierarchy of responses to resources pulses in arid and semi-arid ecosystems. Oecologia 141:211–220
Silvertown JW (1982) Introduction to plant population ecology. Longman Inc., New York, pp 209
Tongway DJ, Cortina J, Maestre FT (2004) Heterogeneidad espacial y gestión de medios semiáridos. Ecosistemas 2004/1 (URL: http://aeet.org/ecosistemas/041/revision5.htm)
Valentini C, d’Herbes JM, Poesen J (1999) Soil and water components of banded vegetation patterns. Catena 37:1–24. doi:10.1016/S0341-8162(99)00053-3
Valladares F, Pugnaire FI (1999) Tradeoffs between irradiance capture and avoidance in semi-arid environments assessed with a crown architecture model. Ann Bot (Lond) 83:459–469. doi:10.1006/anbo.1998.0843
Vallejo VR, Serrasoles I, Cortina J, Seva JP, Valdecantos A, Vilagrosa A (2000) Restoration strategies and actions in Mediterranean degraded lands. In: Enne G, Zanolla Ch, Peter D (eds) Desertification in Europe: mitigation strategies land-use planning. EC DGXII Environment and Climate Program, European Commission, Brussels, pp 211–233
Watkinson AR (1984) Yield-density relationship: the influence of resource of availability on growth and self-thinning in population of Vulpia fasciculata. Ann Bot (Lond) 53:469–482
Weller D (1990) Will the real self-thinning rule please stand up?—a reply to Osawa and Sugita. Ecology 71(3):1204–1207. doi:10.2307/1937389
White J, Harper JL (1970) Correlated changes in plant size and number in plant populations. J Ecol 58:467–485. doi:10.2307/2258284
Yoda K, Kira T, Osawa H, Hozumi H (1963) Intraspecific competition among higher plants. XI Self-thinning in overcrowded pure stands under cultivated and natural conditions. J Inst Polytech Osaka City Univ 14:107–129
Zar JH (1999) Biostatistical analysis, 4th edn. Prentice-Hall Inc., New Jersey, pp 931
Acknowledgements
We thank Adela Blasco for her assistance with ecophysiological assessments and Dr. Juan R. Sánchez for his assistance with the field work. We also thank Dr. Francisco Domingo for his valuable comments on a draft of this manuscript and José Carlos Cristóbal for plant sample analyses. Financial support was provided by the “Efecto de la cubierta vegetal en el balance hídrico y en la disponibilidad y calidad del agua, propuesta para aumentar la recarga de acuíferos” Project, funded by the CICYT (REN2000-0529HID, CGL2004-03627) and by “AQUADAPT: Energy, Environment and Sustainable Development” Project founded by the European Community (EVK1-2001-00149).
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Ramírez, D.A., Bellot, J. Linking population density and habitat structure to ecophysiological responses in semiarid Spanish steppes. Plant Ecol 200, 191–204 (2009). https://doi.org/10.1007/s11258-008-9444-8
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DOI: https://doi.org/10.1007/s11258-008-9444-8