Hydrology, Water Resources and Ecology in Headwaters (Proceedings of the HeadWater'98 Conference held at Meran/Merano, Italy, April 1998). IAHS Pub!, no. 248, 1998. 379 Using spring biota of pristine mountain areas for long-term monitoring MARCO CANTONATI Museo Tridentino di Scienze Naturali, Via Calepina 14, 1-38100 Trento, Italy KARIN ORTLER Institut fir Botanik der Universitàt Innsbruck, Stemwartestrafie 15, A-6020 Innsbruck, Austria Abstract Thirty springs in the Adamello-Brenta Regional Park (Trentino, Italy) distributed over a large altitudinal range (from 1073 to 2172 m a.s.l.) were studied between 1992 and 1996. A high diversity of plant and animal communities including algae (mainly cyanophytes and diatoms), mosses and higher plants, macroinvertebrates (the main groups being midges, stoneflies, caddisflies), water mites, microcrustaceans, and crenobiontic snails was identified. The springs situated in pristine areas allow the detection of slight shifts as well as long-term effects of impacts on their drainage basins much more clearly than freshwater environments altered by human activity. In this paper we discuss the use of spring biota for the definition of the trophic status, ongoing acidification processes, and organic pollution. After a broad screening of the biota within a basic investigation, continuous survey of water mites is recommended for checking the persistence of stable conditions and the survey of diatoms for monitoring acidification and eutrophication processes. INTRODUCTION Pristine environments in remote areas are suitable sites for the detection of environmental changes. This is particularly true for springs because of their characteristic physico-chemical stability. The specific features of these environments have caused the evolution of crenobiontic (living only in springs), crenophilous (living mainly in springs), and crenoxenic (living occasionally in springs) organisms. Most attempts to use spring organisms for monitoring pollution by organic substances and distinguish stable springs from temporary waters were essentially concentrated on macroinvertebrates (Williams, 1991; Bodon & Geiter, 1995). The present study uses for the first time a broad spectrum of organisms to detect environmental changes in order to develop a long-term monitoring programme, i.e. detection of changes and/or trends in biotope/water quality over longer time periods independent from inter-annual variability. Background information about the case study From 1992 to 1996, 30 springs from all major valleys in the Adamello-Brenta Regional Park (618 km 2 ) have been studied. The Adamello mountain group consists of igneous rocks, such as granites, whereas the Brenta group is mostly composed of limestones and dolomites. The springs, distributed over a large altitudinal range