Ecological changes in the highest temporary pond of western Crete (Greece): past, present and future
- 351 Downloads
This study explores the past, present and future ecological changes in the highest Mediterranean temporary pond (Omalos pond) in western Crete, Greece. Data from downcore pollen analysis (including pollen and spores from both aquatic vegetation, and terrestrial herbaceous, arboreal and shrub vegetation), modern vegetation monitoring and existing climate scenarios have been combined to provide a picture of the ecological changes in the pond over the last 13,600 years. Downcore pollen analysis throughout the last 13,600 years indicated the presence of species typical of Mediterranean Temporary Pond (MTP) habitats and suggested relatively drier conditions towards the present. The low number of non-native, cultivated species (such as herbaceous Trifolium and Plantago species) observed over this period suggested relatively low impact from crop agriculture, despite the increasing grazing pressure in the area. In the absence of independent proxies, we cannot reliably distinguish between natural and human-induced changes. The presence of aquatic Isoetes in the palaeo-record indicates the existence of an ephemeral pond in the area as early as the beginning of the Holocene suggesting resilience of the ecosystem over time. However, the degraded state of pollen in depths over 55 cm (i.e. 3600 year BP) increases the uncertainty of the interpretation. Currently, the pond holds 76 plant species belonging to 25 families. Therophytes and chamaephytes were the most frequent, suggesting a typical ephemeral habitat life form spectrum. Species richness was found to increase during spring surveys whereas the highest turnover was observed between summer surveys of consecutive years. Cluster analysis demonstrated a distinct zonation in four vegetation belts from the periphery to the centre of the pond which is typical of these environments. Modelling, based on two IPPC scenarios (A2 and B2), predicted relatively low climate change impacts on the pond’s hydroperiod for the next 100 years (i.e. a decrease of 16 and 24 days, respectively). This reduction in the hydroperiod of the pond will have an effect on the physiognomy and spatial extent of vegetation, particularly for the transitional belts between the core and its outer area, while it will exert more pressure on the pond as a water resource for sheep in the region. However, cumulative effects and complex interactions of climate-driven environmental changes and other anthropogenic disturbances might act synergistically to accelerate impacts in the future.
KeywordsAegean Climate change Lefka Ori Mediterranean Pollen analysis
This research was funded by the LIFE Nature Programme ‘Actions for the conservation of Mediterranean Temporary Ponds in Crete’ LIFE04NAT/GR/000105). We are grateful to Mrs. Christina Fournaraki, curator at the Herbarium of MAICh, for her help in species identification. We would also like to thank two anonymous reviewers and the editors whose comments resulted in a much improved manuscript.
- Álvarez-Cobelas, M., J. Catalan & D. de Garcia Jalón, 2005. Impacts on inland aquatic ecosystems. In Moreno, J. M. (ed.), Effects of Climate Change in Spain. Ministerio de Medio Ambiente, Madrid, Spain: 113–146.Google Scholar
- Bartolomé, C., J. Álvarez, J. Vaquero, M. Costa, M. A. Casermeiro, J. Giraldo & J. Zamora, 2005. Los habitats de interés comunitario de España. Guía Básica. Ministerio de Medio Ambiente. Dirección General para la Biodiversidad, Madrid. http://www.mma.es/portal/secciones/biodiversidad/rednatura2000/documentos_rednatura/tipos_habit_interes.htm.
- Belk, D., 1998. Global status and trends in ephemeral pool invertebrate conservation: Implications for Californian fairy shrimp. In Witham, C. W., D. Belk, W. R. Ferren & R. Ornduff (eds), Ecology. Conservation and Management of Vernal Pool Ecosystems, Sacramento: 147–150.Google Scholar
- Bergmeier, E., 2005. Short Report on the Environment, Flora and Vegetation of the “Omalos Pond”. University of Göttingen, Germany. LIFE Nature 2004 “Actions for the Conservation of the Mediterranean Temporary Ponds in Crete”.Google Scholar
- Blaustein, L. & S. S. Schwartz, 2001. Why study ecology in temporary pools? Journal of Zoology 47: 303–312.Google Scholar
- Brendonck, L. & W. D. Williams, 2000. Biodiversity in wetlands of dry regions (drylands). In Gopal, B., W. J. Junk & J. A. Davis (eds), Biodiversity in Wetlands: Assessment Function and Conservation, Vol. 1. Backhuys Publishers, Leiden: 181–194.Google Scholar
- Chilton, L. & N. J. Turland, 1997. Flora of Crete: a supplement. Marengo Publications, Retford.Google Scholar
- Council of Europe, 1992. Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora. Official Journal of the European Communities L 206: 7–50.Google Scholar
- Dale, V. H., 1997. The relationship between land-use change and climate change. Ecological Processes 7: 753–769.Google Scholar
- Diaz, H. F. & R. S. Bradley, 1997. Temperature variations during the last century at high elevation sites. Climatic Change 21: 21–47.Google Scholar
- Egli, B. R., 1993. Oecologie der Dolinen im Gebirge Kretas (Griechenland) Inaugural Dissertation zur Erlagung der philosophischen Doktorwurde vorgelegt der Philosophischen. Fakultat II der Universitat, Zurich.Google Scholar
- European Commission DG Environment, 2003. Interpretation manual of European Union habitats – directive. Natura 2000, Nature and Biodiversity EUR 25: 32–33.Google Scholar
- Faegri, K. & J. Iversen, 1989. Textbook of Pollen Analysis. John Wiley & Sons, New York.Google Scholar
- Firth, P. & S. G. Fisher (eds), 1992. Global Climate Change and Freshwater Ecosystems. Springer Verlag, New York.Google Scholar
- Gaudillat, V. & J. Haury (coord.), 2002. « Cahiers d’habitats » Natura 2000. Connaissance et gestion des habitats et des espèces d’intérêt communautaire. Tome 3 - Habitats humides. MATE/MAP/MNHN. Éd. La Documentation française, Paris, 457 p. + cédérom. http://natura2000.environnement.gouv.fr/habitats/cahiers.html.
- Goodson, J. M., A. M. Gurnell, P. G. Angold & I. P. Morrissey, 2001. Riparian seed banks: structure, process and implications for riparian management. Progress in Physical Geography 25: 301–325.Google Scholar
- Grillas, P., P. Gauthier, N. Yavercovski & C. Perennou, 2004. Mediterranean Temporary Pools; Vol. 1 – Issues Relating to Conservation, Functioning and Management. Station biologique de la Tour du Valat, France.Google Scholar
- Hammer, O., D. A. T. Harper & P. D. Ryan, 2009. PAST – PAlaeontological STatistics, ver. 1.88. User’s manual.Google Scholar
- IPCC (Intergovernmental Panel on Climate Change), 2007. Climate Change: Working Group I: The Scientific Basis. [Online] Retrieved from the web: http://www.grida.no/climate/ipcc_tar/wg1/008.htm.
- Jahn, R. & P. Schönfelder, 1995. Exkursionflora für Kreta. Ulmer, Stuttgart.Google Scholar
- Kazakis, G. & D. Ghosn, 2006. Investigation of Grazing and Watering Capacity of MTPs (Action A6). Mediterranean Agronomic Institute of Chania, Greece. LIFE Nature 2004 “Actions for the Conservation of the Mediterranean Temporary Ponds in Crete”.Google Scholar
- Kent, M. & P. Coker, 1994. Vegetation Description and Analysis: A Practical approach. Belhaven Press, London.Google Scholar
- Krebs, C. J., 1999. Ecological Methodology, 2nd ed. Addison-Wesley Educational Publishers, Inc.Google Scholar
- Lahr, J., A. O. Diallo, B. Gadji, P. S. Diouf, J. J. M. Bedaux, A. Badji, K. B. Ndour, J. E. Andreasen & N. M. Van Straalen, 2000a. Ecological effects of experimental insecticide applications on invertebrates in Sahelian temporary ponds. Environmental Toxicology and Chemistry 19: 1278–1289.CrossRefGoogle Scholar
- Lodge, D. M., 2001. Responses of lake biodiversity to global changes. In Sala, O. E., F. S. Chapin & E. Huber-Sannwald (eds), Future Scenarios of Global Biodiversity. Springer Verlag, New York: 277–313.Google Scholar
- Madhyastha, M. N., K. C. Shashikumar & P. D. Rekha, 2000. Temporary ponds – a neglected ecosystem. Proceedings of Lake 2000: Restoration of Lakes and Wetlands. Section 6, Limnology, Watershed Hydrology and Monitoring, Paper 6, Bangalore, India.Google Scholar
- Magnusson, J. J., K. E. Webster, R. A. Assel, C. J. Bowser, P. J. Dillon, J. G. Eaton, H. E. Evans, E. J. Fee, R. I. Hall, L. R. Mortsch, D. W. Schindler & F. H. Quinn, 1997. Potential effects of climate changes on aquatic ecosystems: Laurentian Great Lakes and Precambrian Shield region. Hydrological Processes 11: 825–871.CrossRefGoogle Scholar
- McCarthy, J. J., O. V. Canziani, N. A. Leary, D. J. Dokken & K. S. White (eds), 2001. Climate Change 2001: Impacts, Adaptation, and Vulnerability. Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). Cambridge University Press, Cambridge, UK. Available from: http://www.ipcc.ch.
- Metge, G., 1986. Etude des ecosystemes hydromorphes (daja et merdja) de la Meseta Occidentale Marocaine. These Doct. Fac. Sci., Marseille: 280 pp.Google Scholar
- Moore, P. D., J. A. Webb & M. E. Collinson, 1991. Pollen Analysis. Blackwell Scientific, London.Google Scholar
- Poff, N. L., M. A. Brinson & J. W. Day, 2002. Aquatic Ecosystems and Global Climate Change: Potential Impacts on Inland Freshwater and Coastal Wetland Ecosystems in the United States. PEW Center on Global Climate Change, Arlington, VA. Available from: www.pewclimate.org.
- Ramsar Convention Secretariat, 2002. Resolution VIII.33. Guidance for identifying, sustainably managing, and designating temporary pools as Wetlands of International Importance. http://www.ramsar.org/ris/key_ris.htm#type.
- Reille, M., 1995. Pollen et spores d’europe et d’afrique du nord, supplement 1. Laboratoire de Botanique historique et Palynologie, Marseille: 331 pp.Google Scholar
- Rhazi, L., P. Grillas, L. Tan Ham & D. El Khyari, 2001b. The seed bank and the between years dynamics of the vegetation of a Mediterranean temporary pool (NW Morocco). Ecologia Mediterranea 27: 69–88.Google Scholar
- Stamati, F. & N. Nikolaidis, 2006. Technical Report: Hydrology and Geochemistry of the Mediterranean Temporary Ponds of W. Crete. Actions for the Conservation of the Mediterranean Temporary Ponds in Crete, Project Life-Nature 2004. Laboratory of Hydrogeochemical Engineering and Remediation of Soils, Technical University of Crete.Google Scholar
- Thomas, C. D., A. Cameron, R. E. Green, M. Bakkenes, L. J. Beaumont, Y. C. Collingham, B. F. N. Erasmus, M. F. De Siqueira, A. Grainger, L. Hannah, L. Hughes, B. Huntley, A. S. Van Jaarsveld, G. F. Midgley, L. Miles, M. A. Ortegahuerta, A. T. Peterson, O. L. Phillips & S. E. Williams, 2004. Extinction risk from climate change. Nature 427: 145–148.CrossRefPubMedGoogle Scholar
- Turland, N. J., L. Chilton & J. R. Press, 1993. Flora of the Cretan Area. Annotated Checklist and Atlas. HMSO, London.Google Scholar
- Zacharias, I., A. Parasidou, E. Bergmeier, G. Kehayias, E. Dimitriou & P. Dimopoulos, 2008. A “DPSIR” model for Mediterranean temporary ponds: European, national and local scale comparisons. Annales de Limnologie-International Journal of Limnology 44: 243–256.Google Scholar