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The water status of six woody species coexisting in the Sahel (Ferlo, Senegal)

Published online by Cambridge University Press:  10 July 2009

A. Berger
Affiliation:
CEFE – CNRS, BP 5051, 34033 Montpellier Cedex, France
M. Grouzis
Affiliation:
Laboratoire d'Ecologie ORSTOM, BP 1386 Dakar, Senegal
C. Fournier
Affiliation:
CEFE – CNRS, BP 5051, 34033 Montpellier Cedex, France Laboratoire d'Ecologie ORSTOM, BP 1386 Dakar, Senegal

Abstract

In the Sahel during recent decades, anthropogenic disturbance and periods of drought have caused changes in woody species frequency. The internal water status of six coexisting species was analysed to estimate the importance of water constraints in this process. Predawn and midday xylem pressure potential and stomatal conductance were monitored monthly for two years. The relations between xylem pressure potential and transpiration made it possible to determine the hydraulic conductivity of the soil—plant system. Two types of results were obtained. First, there was considerable diversity in water status of the different species. Minimum predawn xylem pressure potentials (dry season) ranged from – 1.5 MPa to – 5 MPa depending on species, with interseasonal variation from 0.08 MPa to 2 MPa. Response to rainfall was very rapid (a few days) or very slow (several months). The three functioning types defined using these results were compared with the phytogeographical status of the species. Second, more specific phenomena were observed, (a) Some species (Balanites aegyptiaca and Boscia senegalensis) showed an imbalance between the predawn xylem pressure potential and the soil water status during the rainy season; (b) a sharp increase in xylem pressure potential was observed in deciduous species in the middle of the dry season; probably related to bud break; and (c) the water status was always favourable for Combrelum glutinosum. The few remaining individuals seem to benefit from very favourable subsoil water supply conditions.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1996

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References

LITERATURE CITED

Akpo, L. E. 1993. Influence du couvert ligneux sur la structure et le fonctionnement de la strate herbacée en milieu sahélien. Document ORSTOM No. 93. 174 pp.Google Scholar
Ameglio, T. & Cruiziat, P. 1992. Alternance tension/pression de la sève dans le xylème chez le Noyer pendant l'hiver: rôle des températures. Comptes Rendus de l'Académie des Sciences de la Vie, Paris 315, Série 111:429435.Google Scholar
Bate, G. C., Furniss, P. R. & Pendle, B. G. 1982. Water relations of southern African savannas. Pp. 336358 in Huntley, B. J. & Walker, B. H. (eds). Ecology of tropical savannas. Ecological Studies 42. Springer-Verlag, Berlin, Heidelberg, New York.CrossRefGoogle Scholar
Berger, A. 1969. Transpiration, potentiel hydrique et résistance à la circulation de l'eau dans une culture d'Hélianthus annum L. Oecologia Plantarum 4:123154.Google Scholar
Berger, A. & Ramadan, I. 1979. Transferts d'eau dans le système sol-plante. Revue d'Ecologie (Terre et Vic) Suppl. 2:93102.Google Scholar
Boaler, S. B. 1966. Ecology of miombo site, Lupa North Forest Reserve, Tanzania. II – Plant communities and seasonal variation in the vegetation. Journal of Ecology 54:465479.CrossRefGoogle Scholar
Borchert, R. 1994. Water status and development of tropical trees during seasonal drought. Trees: Structure and Function 8:115125.CrossRefGoogle Scholar
Boudet, G. 1977. Contribution au contrôle continu des pâturages tropicaux en Afrique occidentale. Revue de l'élevage et de la médicine vétérinaire des pays tropicaux 30:387406.Google Scholar
Boyer, J. S. 1969. Free energy transfer in plants. Science 163:12191220.CrossRefGoogle ScholarPubMed
Braun, H. J. 1984. The significance of the hydrosystem for osmotic water shifting as the second principle of water sap ascent, with some thoughts concerning the evolution of trees. IAWA Bulletin 5:275294.CrossRefGoogle Scholar
Brouwer, R. 1954. Water absorption by the roots of Vicia faba at various transpiration strengths. III. Changes in water conductivity artificially obtained. Proceedings of the Koninklijke Nederlandse Akademie van Wetenschapen Series C, 57:6880.Google Scholar
Bullock, S. H. & Solis-Magallanes, J. A. 1990. Phenology of canopy trees of a tropical deciduous forest in Mexico. Biotropica 22:2235.CrossRefGoogle Scholar
Cortes, P. M. & Sinclair, T. R. 1985. The role of osmotic potential in spring sap flow of mature sugar maple trees (Acer saccharum Nark). Journal of Experimental Botany 36:1224.CrossRefGoogle Scholar
Cresswell, C. F., Ferrar, P., Grunow, J. O., Grossman, D., Rutherford, M. C. & Van Wyk, J. J. P. 1982. Phytomass, seasonal phenology and photosynthetic studies. Pp. 476497 in Huntley, B. J. & Walker, B. H. (eds). Ecology of tropical savannas. Ecological Studies 42. Springer-Verlag, Berlin, Heidelberg, New York.CrossRefGoogle Scholar
Daubenmire, R. 1972. Phenology and other characteristics of tropical semi-deciduous forest in northwestern Costa Rica. Journal of Ecology 60:147170.CrossRefGoogle Scholar
Frederiksen, P. & Lawesson, J. E. 1992. Vegetation types and patterns in Senegal based on multivariate analysis of field and NOAAA-AVHRR satellite data. Journal of Vegetation Science 3:535544.CrossRefGoogle Scholar
Goldstein, G. & Sarmiento, G. 1987. Water relations of trees and grasses and their consequences for the structure of savanna vegetation. Pp. 1338 in Walker, B. H. (ed.). Determinants of tropical savanna. IUBS Monograph Series No. 3.Google Scholar
Goldstein, G., Sarmiento, G. & Meinzer, F. 1986. Patrones diarios y estacionales en las relaciones hidricas de arboles siempreverdes de la sabana tropical. Acta Oecologica, Oecologio Plantarum 7:107119.Google Scholar
Grouzis, M. & Sicot, M. 1980. A method for the phenological study of browse population in the Sahel: the influence of some ecological factors. Pp. 233240 in Le Houérou, H. N. (ed.). Browse in Africa. ILCA, Addis Ababa.Google Scholar
Haas, R. M. & Dodd, J. D. 1972. Water stress patterns in Honey Mesquite. Ecology 53:674680.CrossRefGoogle Scholar
Hopkins, B. 1970. Vegetation of the Olokemeji Forest Reserve, Nigeria. VI – The plants of the forest site with special reference to their seasonal growth. Journal of Ecology 58:765793.CrossRefGoogle Scholar
Jones, H. G. 1978. Modelling diurnal trends of leaf water potential in transpiring wheat. Journal of Applied Ecology 15:613626.CrossRefGoogle Scholar
Kaufmann, M. R. 1977. Soil temperature and drying cycle effects on water relations of Pinus radiata. Canadian Journal of Botany 55:24132418.CrossRefGoogle Scholar
Khalfaoui, J. L. B. 1991. Determination of potential length of the crop growing period in semi-arid regions of Senegal. Agricultural and Forest Meteorology 55:251263.CrossRefGoogle Scholar
Kuppers, M., Neales, T. F., Kuppers, B. I. L., Swan, A. G. & Myers, B. A. 1987. Hydraulic flow characteristics in the lignotuberous mallee Eucalyptus beheriana F. Muell. in the field. Plant, Cell and Environment 10:2737.CrossRefGoogle ScholarPubMed
La Wesson, J. E. 1990. Sahelian woody vegetation in Senegal. Vegetatio 86:161174.CrossRefGoogle Scholar
Le Houérou, H. N. 1989. The grazing land ecosystems of the African Sahel. Ecological Studies, Vol. 75. Springer-Verlag. 282 pp.CrossRefGoogle Scholar
Maydell, H. J. von. 1983. Arbres el arbustes du Sahel. Leurs caractéristiques et leurs utilisations. Schriftenreihe No. 147. Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ), Eschborn, Germany.Google Scholar
Meinzer, F., Seymour, V. & Goldstein, G. 1983. Water balance in developing leaves of four tropical savanna woody species. Oecologia 60:237243.CrossRefGoogle ScholarPubMed
Monson, R. K. & Smith, S. D. 1982. Seasonal water potential components of Sonoran desert plants. Ecology 63:113123.CrossRefGoogle Scholar
Myers, B. A. & Neales, T. F. 1984. Seasonal changes in the water relations of Eucalyptus beheriana F. Muell. and E. microcarpa (Maiden) in the field. Australian Journal of Botany 32:495510.CrossRefGoogle Scholar
Njoku, E. 1963. Seasonal periodicity in the growth and development of some forest trees in Nigeria. I – Observations on mature trees. Journal of Ecology 51:617624.CrossRefGoogle Scholar
Ourcival, J. M. & Berger, A. 1995. Equilibrium between soil water potential and predrawn water potential of two pre-saharian shrub species of Tunisia. Journal of Arid Environment 30:175183.CrossRefGoogle Scholar
Passioura, J. B. 1980. The transport of water from soil to shoot in wheat seedlings. Journal of Experimental Botany 31:333345.CrossRefGoogle Scholar
Piot, J. & Diaite, I. 1983. Systimes de production d'élevage au Sénégal. Etude du couvert ligneux. GRIZA/LAT, CTFT, Nogent/Marne, ISRA/LNERV, Dakar. 37 pp.Google Scholar
Poulet, A. R. & Poupon, H. 1978. L'invasion d'Arvicanthus hiloticus dans les Sahel sénégalais en 1975–1976 et ses conséquences pour la strate ligneuse. Revue d'Ecologie (Terre et Vie) 32:161193.Google Scholar
Poupon, H. & Bille, J. C. 1974. Recherches écologiques sur une savane sahélienne du Ferlo septentrional, Sénégal: Influence de la sécheresse de l'année 1972–1973 sur la strate ligneuse. Revue d'Ecologie (Terre et Vie) 28:4975.Google Scholar
Ranney, T. G. & Davidson, D. 1992. Analysis of pressure-volume data using segmented, non-linear regression algorithms. Horticultural Science 27:275.Google Scholar
Ritchie, G. A. & Roden, J. R. 1985. Comparison between two methods of generating pressure-volume curves. Plant, Cell and Environment 8:4953.CrossRefGoogle Scholar
Sarmiento, G., Goldstein, G. & Meinzer, F. 1985. Adaptative strategies of woody species in neotropical savannas. Biological Review 60:315355.CrossRefGoogle Scholar
Sauter, J. J. 1980. Seasonal variation of sucrose content in the xylem sap of Salix. Zeitschrift für Planzenphysiologie B 98:377391.CrossRefGoogle Scholar
Sauter, J. J. 1988. Seasonal changes in the efflux of sugars from parenchyma cells into the apoplast in poplar stems (Populus × canadensis ‘robusta’). Trees: Structure and function 2:242249.CrossRefGoogle Scholar
Schulte, P. J. & Hinckley, T. M. 1985. A comparison of pressure-volume curve data analysis techniques. Journal of Experimental Botany 36:15901602.CrossRefGoogle Scholar
Schulze, E. D., Hall, A. E., Lange, O. L., Evenari, M., Kappen, L. & Bushbom, U. 1980. Long-term effects of drought on wild and cultivated plants in the Negev Desert. Oecologia 45:1118.CrossRefGoogle ScholarPubMed
Sedgley, R. H., Seaton, K. A. & Stern, W. R. 1973. A field method for determining soil water availability to crops. Pp. 527530 in Slatyer, R. A. (ed.). Plant response to climatic factors. Ecology and Conservation 5, Paris.Google Scholar
Sharman, M. 1987. Vegetation ligneuse sahélienne. Global Environment Monitoring System, Série Sahel 7:185.Google Scholar
Sobrado, M. A. 1986. Aspects of tissue-water relations and seasonal changes of leaf water potential components of evergreen and deciduous species coexisting in tropical dry forests. Oecologia 68:413416.CrossRefGoogle ScholarPubMed
Steudle, E. 1992. The biophysics of plant water: compartmentadon, coupling with metabolic processes, and flow of water in plant roots. Pp. 173204 in Somero, G. N., Osmond, C. B. & Bolis, C. L. (eds). Comparative analysis of water relationships of the organismic, cellular, and molecular levels. Springer-Verlag, Heidelberg.Google Scholar
Stoker, R. & Weatherley, P. E. 1971. The influence of the root system on the relationship between the rate of transpiration and depression of leaf water potential. New Phytologist 70:547554.CrossRefGoogle Scholar
Tinker, P. B. 1976. Transport of water to plant roots in soil. Philosophical Transactions of the Royal Society of London B 273:445461.Google Scholar
Ullman, I. 1985. Diurnal courses of transpiration and stomatal conductance of sahelian and saharian Acacias in the dry season. Flora 176:383409.Google Scholar
Ullman, I. 1989. Stomatal conductance and transpiration of Acacia under field conditions: similarities and differences between leaves and phyllodes. Trees: Structure and Function 3:4556.Google Scholar