Journal cover Journal topic
Hydrology and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Hydrol. Earth Syst. Sci., 16, 3165-3182, 2012
© Author(s) 2012. This work is distributed
under the Creative Commons Attribution 3.0 License.
Research article
06 Sep 2012
A novel approach to analysing the regimes of temporary streams in relation to their controls on the composition and structure of aquatic biota
F. Gallart1, N. Prat2, E. M. García-Roger2,*, J. Latron1, M. Rieradevall2, P. Llorens1, G. G. Barberá3, D. Brito4, A. M. De Girolamo5, A. Lo Porto5, A. Buffagni6, S. Erba6, R. Neves4, N. P. Nikolaidis7, J. L. Perrin8, E. P. Querner11, J. M. Quiñonero3, M. G. Tournoud8, O. Tzoraki7, N. Skoulikidis9, R. Gómez10, M. M. Sánchez-Montoya10, and J. Froebrich11 1IDAEA, CSIC, Jordi Girona 18, 08034 Barcelona, Spain
2FEM, D. Ecologia, UB, 08028 Barcelona, Spain
3CEBAS, CSIC, 30100 Murcia, Spain
4IMAR, 3004-517 Coimbra, Portugal
5IRSA, CNR, 70132 Bari, Italy
6IRSA, CNR, 20861 Brugherio MB, Italy
7EED, TUC, 73100 Chania, Greece
8Université Montpellier 2, 34095 Montpellier, France
9HCMR, 19013 Anavissos, Athens, Greece
10Dept. Ecología e Hidrología, UMU, 30100 Murcia, Spain
11Alterra, 6708 PB, Wageningen, The Netherlands
*present address: ICBIBE, UV, 46980 Paterna, València, Spain
Abstract. Temporary streams are those water courses that undergo the recurrent cessation of flow or the complete drying of their channel. The structure and composition of biological communities in temporary stream reaches are strongly dependent on the temporal changes of the aquatic habitats determined by the hydrological conditions. Therefore, the structural and functional characteristics of aquatic fauna to assess the ecological quality of a temporary stream reach cannot be used without taking into account the controls imposed by the hydrological regime. This paper develops methods for analysing temporary streams' aquatic regimes, based on the definition of six aquatic states that summarize the transient sets of mesohabitats occurring on a given reach at a particular moment, depending on the hydrological conditions: Hyperrheic, Eurheic, Oligorheic, Arheic, Hyporheic and Edaphic. When the hydrological conditions lead to a change in the aquatic state, the structure and composition of the aquatic community changes according to the new set of available habitats. We used the water discharge records from gauging stations or simulations with rainfall-runoff models to infer the temporal patterns of occurrence of these states in the Aquatic States Frequency Graph we developed. The visual analysis of this graph is complemented by the development of two metrics which describe the permanence of flow and the seasonal predictability of zero flow periods. Finally, a classification of temporary streams in four aquatic regimes in terms of their influence over the development of aquatic life is updated from the existing classifications, with stream aquatic regimes defined as Permanent, Temporary-pools, Temporary-dry and Episodic. While aquatic regimes describe the long-term overall variability of the hydrological conditions of the river section and have been used for many years by hydrologists and ecologists, aquatic states describe the availability of mesohabitats in given periods that determine the presence of different biotic assemblages. This novel concept links hydrological and ecological conditions in a unique way. All these methods were implemented with data from eight temporary streams around the Mediterranean within the MIRAGE project. Their application was a precondition to assessing the ecological quality of these streams.

Citation: Gallart, F., Prat, N., García-Roger, E. M., Latron, J., Rieradevall, M., Llorens, P., Barberá, G. G., Brito, D., De Girolamo, A. M., Lo Porto, A., Buffagni, A., Erba, S., Neves, R., Nikolaidis, N. P., Perrin, J. L., Querner, E. P., Quiñonero, J. M., Tournoud, M. G., Tzoraki, O., Skoulikidis, N., Gómez, R., Sánchez-Montoya, M. M., and Froebrich, J.: A novel approach to analysing the regimes of temporary streams in relation to their controls on the composition and structure of aquatic biota, Hydrol. Earth Syst. Sci., 16, 3165-3182, doi:10.5194/hess-16-3165-2012, 2012.
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