Impact of land use in catchment and human activities on water, sediment and vegetation of Mediterranean temporary pools.

The vegetation and physical and chemical characteristics of the water and sediment in ten temporary pools submitted to various anthropogenic disturbance were studied in Morocco over two hydrological cycles (1997-1998 and 1998-1999). Results of multivariate and parametric analyses show that disturbance has a significant impact on water and sediment. Agriculture in the catchment resulted in higher levels of N and the use of detergent to higher levels of phosphorus in both water and sediment. Mineral extraction resulted in higher depth and longer duration of flooding. Vegetation characteristics were better correlated to hydrology (water depth, duration of flooding) than to nutrient variables. These results suggest that although agriculture in the catchment contribute in modifying the sediment characteristics, the impact on vegetation and its conservation value is limited. However, care should be taken of the long-term effects of agriculture through cumulative effects and of the possible consequences of changing the agricultural practices.

[1]  Richard A Vollenweider.  Les bases scientifiques de l'eutrophisation des lacs et des eaux courantes sous l'aspect particulier du phsophore et de l'azote comme facteurs d'eutrophisation , 1970 .

[2]  James B. Grace,et al.  The relationship between species richness and community biomass: the importance of environmental variables. , 1994 .

[3]  J. L. Doust,et al.  Wetland management and conservation of rare species , 1995 .

[4]  G. E. Hutchinson,et al.  A treatise on limnology. , 1957 .

[5]  F. Woodward,et al.  Patterns in tree species richness as a test of the glacial extinction hypothesis , 1989, Nature.

[6]  T. Lopez,et al.  Limnological comparison of two peridunar ponds in the Doñana National Park (Spain) , 1991, Archiv für Hydrobiologie.

[7]  J. Toja,et al.  Limnological description of four temporary ponds in the Doñana National Park (SW, Spain) , 1995 .

[8]  Darren S. Ryder,et al.  Australian Freshwater Ecology: Processes and Management , 1999 .

[9]  James B. Grace,et al.  A Structural Equation Model of Plant Species Richness and Its Application to a Coastal Wetland , 1997, The American Naturalist.

[10]  M. Godron,et al.  Profils écologiques et liaisons interspécifiques. Deux approches complémentaires appliquées à l'étude des groupements de mauvaises herbes des cultures du Saïs (Maroc central) , 1995 .

[11]  David J. Currie,et al.  Large-scale biogeographical patterns of species richness of trees , 1987, Nature.

[12]  Jenny Davis,et al.  Wetlands for the future , 1998 .

[13]  Dan B. Martin,et al.  The effect of cultivation on sediment composition and deposition in prairie pothole wetlands , 1987 .

[14]  A. Page.  Methods of soil analysis. Part 2. Chemical and microbiological properties. , 1982 .

[15]  P. Keddy,et al.  Prediction of Rarities from Habitat Variables: Coastal Plain Plants on Nova Scotian Lakeshores , 1992 .

[16]  D. Whigham,et al.  Wetlands of the World I: Inventory, Ecology and Management. , 1995 .

[17]  W. F. Millington,et al.  The biology of aquatic vascular plants , 1967 .

[18]  Carlos M. Duarte,et al.  Biomasa de macrófitos acuáticos en la marisma del parque nacional de Doñana (SW España): importancia y factores ambientales que controlan su distribución , 1990, Limnetica.

[19]  Robert M. May,et al.  The Search for Patterns in the Balance of Nature: Advances and Retreats , 1986 .

[20]  P. White,et al.  Topographic models of vascular plant richness in the southern Appalachian high peaks , 1988 .

[21]  A. Thiéry,et al.  La faune des mares temporaires, son originalité et son intérêt pour la biodiversité des eaux continentales méditerranéennes , 1998 .

[22]  Irmgard Blindow,et al.  Decline of charophytes during eutrophication: Comparison with angiosperms , 1992 .

[23]  Elizabeth A. Crowe,et al.  Vegetation zones and soil characteristics in vernal pools in the Channeled Scabland of eastern Washington , 1994 .

[24]  P. Quézel.  La végétation des mares transitoires à Isoetes en région méditerranéenne, intérêt patrimonial et conservation , 1998 .