PREFACE BIOLOGICAL AND CHEMICAL ...

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forest decline in the Vosges Mountains (Poszwa et al., 2002). We do hope that our efforts and the high-quality scientific contributions will stimulate further interest ...
PREFACE BIOLOGICAL AND CHEMICAL PERSPECTIVES OF ECOSYSTEM DISTURBANCE A. CHABBI∗ and R. F. HÜTTL Department of Soil Protection and Recultivation, Faculty of Environmental Sciences, BTU-Cottbus, Postfach 101344, D-03013 Cottbus, Germany (∗ author for correspondence, e-mail: [email protected] fax: (49) 355 62323)

1. Introduction On a global scale, various human activities result in ecosystem disturbance. For example acid rain, a growing mining industry, intensive agriculture and widespread urbanization are processes that have disturbed many aquatic and terrestrial ecosystems. As a consequence, the boundaries of forests and grasslands have been shifting, while soil erosion and desertification are reducing the ability of these systems to support biomass production. Wetlands particularly have been destroyed at an alarming rate. Extended flooding, high sedimentation rates or nutrient transportation loads, and increased concentrations of various pollutants have impacted soils and vegetation, disrupting many natural processes within these ecosystems (Pezeshki et al., 2001). Ecosystem disturbance caused by open-cast mining leads to new land surfaces that are usually difficult to restore. There are many problems related to the restoration of ecosystems, e.g. on mined land, because we still lack a clear understanding of the functional chemistry of the spoil material (Bradshaw and Hüttl 2001). And even if we succeed in restoring a disturbed ecosystem, one of the fundamental questions that is still a matter of debate is whether or not this restoration leads to the development of an ecosystem with sufficient functional integrity to resemble the natural state. In fact, disturbances brought about by human activities not only have altered the physical and chemical conditions of the impacted sites or even landscapes, but also have lead to the profound changes in flora and fauna now occurring in most disturbed ecosystems. Moreover, basic questions on the specific interactions and functions of different processes that take place in disturbed ecosystems remain to be answered. Water, Air, and Soil Pollution 3: 3–6, 2003. © 2003 Kluwer Academic Publishers. Printed in the Netherlands.

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It is clear that we have as yet inadequate information about the functioning of ecosystems that would let us predict their responses to disturbance. In spite of the great attention to ecosystem disturbance (Walker, 1999; Schindler, 1990; Carpenter et al., 1995), the question related to predicting responses is an unresolved problem and remains among the greatest challenges to ecology. This is because (i) disturbed ecosystems are often, for a longer period, in a state of succession of species and communities in a manner that is difficult to predict and (ii) we still have a basic methodological problem of how to measure disturbance (Cole, 1998). Understanding ecosystem response to disturbance still requires a precise definition of what should be considered disturbance. The common definitions of disturbance (e.g. White and Pickett, 1985; Van Andel and Van den Burg, 1987) overlap considerably and they are relatively vague.

2. This Special Issue This Special Issue does not attempt to establish a new definition of the term disturbance, but focuses on a comprehensive and updated overview of how disturbance may change the prevailing conditions, thus creating a disorder in the normal functioning of a given biological or ecological system. The papers presented here deal with a number of environmental disturbances such as the algal growth physiology in eutrophic estuaries (Raven and Tylor, 2000), the nutrient availability and colonization in acidic lakes with respect to the importance of chemical buffering (Nixdorf et al., 2002), the chemistry and microbiology of abandoned coal and metal mines (Johnson, 2002) and metal cycling and the processes controlling alkalinity generation in acidic impacted lake sediments (Küsel, 2002). Some other studies focus on the problem of metal retention or mobilization in the rhizosphere (Jacob and Otte, 2002) and the mechanisms controlling internal metal distribution (Chabbi, 2002). Other papers present recent findings; for example, on the impacts of deforestation on stream water quality (Neal et al., 2002), the effect of leaching and fly ash amelioration on mid- to long-term chemical soil properties (Schaaff, 2002), the impact of lignite on soil organic matter composition and the biogeochemical functioning of the ecosystem (Rumpel and Kögel-Knabner, 2002) and the role of organic matter in maintaining marsh vegetation in sediment-deficient coastal environments (DeLaune and Pezeshki, 2002). And finally, two papers address the use of stable isotopes as tools to follow the retention of pollutant S in peatlands (Novák et al. 2002) or to explain the cause of forest decline in the Vosges Mountains (Poszwa et al., 2002). We do hope that our efforts and the high-quality scientific contributions will stimulate further interest in and work on this fascinating topic which we believe concerns many of the world’s ecosystems.

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Acknowledgements We wish to thank all the authors for preparing the papers for this special issue. This project could not have been accomplished without a large number of outstanding peers that did a great job helping us in the review process. References Bradshaw, A. D. and Hüttl, R. F.: 2001, ‘Future minesite restoration involves a broader approach’, Ecol. Eng. 17, 87–90. Carpenter S. R., Chisholm, S. W., Krebs, C. J., Schindler, D. W. and Wright, R. F.: 1995, ‘Ecosystem experiments’, Science 269, 324–327. Cole, C. A.: 1998, ‘Theoretical function or functional theory? Issues in wetland creation’, in A. J. McComb and J. A. Davis (eds.), Wetland for the Future, Gleneagles Publishing, Adelaide, pp. 679–690. Chabbi, A.: 2002, ‘Metal concentrations in porewater of Lusatian lignite mining sediments and internal metal distribution in Juncus bulbosus’, Water, Air and Soil Pollution: Focus 3, 105–117. DeLaune, R. D. and Pezeshki, S. R.: ‘The role of soil organic carbon in maintaining surface elevation in rapidly subsiding U. S. Gulf of Mexico coastal marshes’, Water, Air and Soil Pollution: Focus 3, 167–179. Jacob, D. L. and Otte, M. L.: 2002, ‘Conflicting processes in the wetland plant rhizosphere: Metal retention or mobilization?, Water, Air and Soil Pollution: Focus 3, 91–104. Johnson, D. B.: 2002, ‘Chemical and microbiological characteristics of mineral spoils and drainage waters at abandoned coal and metal mines’, Water, Air and Soil Pollution: Focus 3, 47–66. Küsel, K.: 2002, ‘Microbial cycling of iron and sulphur in acidic coal mining lake sediments’, Water, Air and Soil Pollution: Focus 3, 67–90. Neal, C., Reynolds, B., Neal, M., Wickham, H., Hill L. and Pugh, B.: 2002, ‘The impact of conifer harvesting on stream water quality: A case study in mid-Wales’, Water, Air and Soil Pollution: Focus 3, 119–138. Novák, M., Adamová, M. and Miliˇci´c, J.: 2002, ‘Sulfur metabolism in two polluted Sphagnum peat bogs: A combined 34 S – 35 S – 210 Pb study’, Water, Air and Soil Pollution: Focus 3, 181–200. Nixdorf, B., Lessmann, D. and Steinberg, C. E. W.: 2002, ‘The importance of chemical buffering for pelagic and benthic colonization in acidic waters’, Water, Air and Soil Pollution: Focus 3, 27–46. Pezeshki, S. R., Chabbi, A. and Ernst, W. H. O.: 2001, ‘Plant and organisms in wetland environments’, Env. & Exp. Bot. 46, 191–193. Poszwa, A., Wickman, T., Dambrine, E., Ferry, B., Dupouey, J., Helle, G., Schleser, G. and Breda, N. A.: 2002 ‘Retrospective isotopic study of spruce decline in the Vosges mountains (France)’, Water, Air and Soil Pollution: Focus 3, 201–222. Raven, J. A. and Taylor, R.: 2002, ‘Macroalgal growth in nutrient-enriched estuaries: A biogeochemical perspective’, Water, Air and Soil Pollution: Focus 3, 7–26. Rumpel, C. and Kögel-Knabner, I.: 2002, ‘Characterisation of organic matter and carbon cycling in rehabilitated lignite-rich mine soils’, Water, Air and Soil Pollution: Focus 3, 153–166. Schaaf, W.: 2002, ‘Leaching induced changes in substrate and solution chemistry of mine soil microcosms’, Water, Air and Soil Pollution: Focus 3, 139–152. Schindler, D.: 1990, ‘Experimental perturbations of whole lakes as test of hypotheses concerning ecosystem structure and function’, Oikos 57, 25–41. Van Andel, J. and Van den Burg, J. P.: 1987, ‘Disturbance of grasslands. Causes, effects, and processes’, in J. Van Andel, J. P. Bakker and R. W. Snaydon (eds.), Geobotany 10, Junk, Dordrecht, pp. 3–13.

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Walker, L.: 1999, Ecosystem of Disturbed Ground, Elsevier, 868 pp. White, P. S. and Pickett, S. T. A.: 1985, ‘Natural disturbance and patch dynamics: An introduction’, in S. T. A. Pickett and P. S. White (eds.), The Ecology of Natural Disturbance and Patch Dynamics, Academic press, Orlando, Florida, pp. 3–13.