THROUGHFALL DEPOSITION OF SULFUR TO A MIXED OAK AND PINE FOREST IN ISRAEL

The deposition of sulfur in a forest site on Mt. Carmel was monitored during the years 1989-1992. Wet deposition, bulk deposition and dry de position were monitored on an open site. Throughfall and stemflow were sampled in a natural, mixed pine (Pinus halepensis) and oak (Quercus calliprinos) forest. In more than 65% of the rain events, the pH of we t deposition was acidic (less than or equal to 5.6) and in nearly 40% of the events it was strongly acidic. The average wet deposition was 1 2.5 kgha(-1)yr(-1) SO4-S. This suggested that the wet deposition of SO 4-S on the Carmel was in the upper range of unpolluted areas. Bulk dep osition contributed 14.3 kgha(-1)yr(-1) SO4-S. Coarse-grained dry depo sition averaged to 58 kgha(-1)yr(-1) and the average deposition rate o f gypsum was 4.9 kgha(-1)yr(-1) containing 0.92 kgha(-1)yr(-1) sulfur. Pine throughfall contained 38 kg ha(-1)yr(-1) S and oak throughfall c ontained 18 kgha(-1)yr(-1). Pine throughfall thus contained approximat ely twice as much S than oak throughfall, probably as a result of the much larger specific surface area of pine. Stemflow was negligible. Th e total S deposition on Mt. Carmel was considerably larger than in unp olluted forests of U.S. and Canada, but smaller than in polluted fores ts of Germany. The pine forests on the western slopes of the central m ountain range seemed to have the important function of ''filtering'' t he air masses that come From the western coastal area, thus preventing S pollution advancing inland. Copyright (C) 1996 Elsevier Science Ltd .