( ~ Pergamon Chemosphere, Vol. 36, No. 4-5, pp. 1055-1060, 1998 © 1998Elsevier Science Ltd All rightsreserved.Printedin GreatBritain 0045-6535/98$19.00+0.00 PII: S0045-6535(97) 10171-0 BIODIVERSITY AND STRESS LEVEL IN FOUR FORESTS OF THE ITALIAN ALPS P. Bonavita ~, C. Chemini ~, P. Ambrosi2, S. Minerbi3, C. Salvadori2 and C. Furlanello4 Centro di Ecologia Alpina, 1-38040 Viote del Monte Bondone, Trento, italy (bonavita@cea.itc.it) 2 Istituto Agrario di S. Michele all'Adige, U. O. Foreste, 1-38010 S. Michele a/A., Trento, Italy 3 Ispettorato per-le Foreste, Provincia Autonoma di Bolzano, I-39100 Bolzano, Italy 4 lstituto per la Ricerca Scientifica e Tecnologica, 1-38050 Povo, Trento, Italy Received in Italy 14-19 September 1996; accepted 1 February 1997 ABSTRACT Diversity patterns of plants, fungi and arthropods were studied in 4 forest sites in the Provinces of Bolzano and Trento (Italian Alps). Two deciduous mi×ed forests at low altitude (560 and 680 m), and two spruce forests close to the timber line (1750 and 1780 m) werc sampled; 2351 species were identified. Data on climate, land use and stress in the forests were correlated with species diversity. Species richness was higher in the deciduous forests, and a great turnover of species occurred between the deciduous and coniferousstands. Similar patterns in some diversityparameters were recorded. (~)1998 Elsevier Science Ltd INTRODUCTION Studies of the relationship between biodiversity and the functioning of ecosystems have often led to controversial conclusions, resulting in conflicting hypotheses and theoretical foundations [1]. Biodiversity is often evaluated as a measure of environmental quality [2, 3, 4, 5, 6], although usually in the absence of axioms concerning the functional role of species diversity. The aim of this study was to assess species diversity in assemblages of plants, fungi and arthropods from 4 mountain forests in relation to different environmental conditions and stress levels Inventory and monitoring activities were carried out under the auspices of the International Cooperative Programme on Integrated Monitoring (ICP/1M) under the UN ECE Long-Range Transboundary Air Pollution Convention, Geneva 1979 [7]. STUDY SITES The species diversity of plants, fungi and arthropods was studied in 4 permanent plots in the Provinces of Trento and Bolzano (Italian Alps). Two study sites (Monticolo, 0.95 ha; Pomarolo, 2 ha) consisted of deciduous forests at low altitude (560 and 680 m, respectively), dominated by oaks (Quercuspubescens, Q. robur), flowering ash (Fraxinus ornus), and 1055