In the late sixties and early seventies the processes of intensive erosion prevailed in the catchment and channel of the torrent Lonjinski Potok, Serbia (Yugoslavia). As the consequence the village Lonjin and the very important road Belgrade - Loznica - Uzice, Serbia (Yugoslavia). In the period 1973-1980, significant erosion control works (ECW) were performed in the watershed and in the channel of the Lonjinski Potok torrent. As the results of this the processes of low erosion occur in the watershed and sediment transport is under limit of the runoff regime. Now, runoff regime is balanced without the floods and long drought period. According his quality water belongs to the first classe. Results of research shows that erosion control works are, also, very important factor for balanced runoff regime and water quality.

In this paper we have pointed out the hydrogeological condition in the catchment area of the Jablanica river in the south Serbia (Yugoslavia). The two units are separately presented here. The first one is mountainous part of the catchment area upstream of the gaging station of Lebane and the second one is the part of the terrain in the plain down stream to the river mounth near Pecenjevac. The hydrogeological characteristics of the two mentioned regions are given to explain the reasons of existing the constant flow of the Jablanica to Lebane and its disappearing course in the period of recession in the plain downstream. The quality of water in the Jablanica river at Lebane is good. Down stream of this gaging station the waste water collector flows into the river. In the part of recession period the ratio between them is unfavourable. We have also discussed the quality of water at the gaging station of Pecenjevac and pointed out the function of sandy-gravel deposits in the process of natural purification of the Jablanica flow.

During the summer 1998 the second phase of Cadastre of Water Objects on the Teaching Base Goc, on the Goc mountain, in central Serbia (Yugoslavia) was done. Investigation was carried out on the territory of 20 square km, with serpentine as parent rock. Serpentine is decomposed in the surface layer, with sceletal soil up to 50 cm deep, insignificant retention attributes. Dominate surfaces under bare lands, meadows, pastures and degraded forest stands. 35 springs were registered, small volume yield (up to 0.29 l*/s), with pH=7.5 to pH8.5, electrical conductivity from 80 up to 800 microS*/cm, temperature 7.0-17.0 deg C. Springs are permanent, but on the higher parts could dry up. Water level in the serpentine has small hydraulic gradient, with slope to the zones of out flow, in other words, to the local erosion base. Hydrogeological characteristics of serpentine were analyzed detailed.

The increased inorganic nitrogen (N) deposition in the last decades has become a major concern for the health of forests. In forest ecosystem, where N might no longer be limiting to primary production, the excess N is thought to be related to forest decline and a concept of ‘N saturation ‘ has been developed. In particular, N, in the form of NH4, in excess to plant and microbial demands could lead to soil acidification if nitrified in the soil and leached, causing loss of base cations or mobilisation of phytotoxic aluminium. As part of the CORE project (CEC), investigating nutrient dynamics in European coniferous forest soils, we studied the effects of continuously increased (NH4)2SO4 deposition and soil characteristics on Norway spruce (Picea abies [L.] Karst) and Scots pine (Pinus sylvestris L.) fine root biomass, vitality and chemistry with an ingrowth core technique. The same experiment was performed in a Norway spruce stand on clay soil (Grizedale, UK) and a Scots pine stand on sandy soil (Wekerom, NL), using soil from each of the two sites. Root-free ingrowth cores reproduced organic and mineral soil horizons to 15 cm depth. They were covered to exclude native throughfall and watered every 2 weeks with throughfall or throughfall with (NH4)2SO4 added to increase deposition by 75 kg ha-1 a-1 NH4+-N. The ingrowth cores were sampled after 19 months, divided into layers, roots washed and analysed for biomass, necromass, root length, root tip number (RTN), root tip vitality and fine root chemistry. A previous field experiment had shown high soil solution Al concentrations at both sites, and an increase in NO3- and Al concentrations in response to increased (NH4)2SO4 deposition at the Grizedale site. The effects of high (NH4)2SO4 deposition depended on tree species, soil type and soil horizon. For Norway spruce, (NH4)2SO4 deposition did not result in any significant changes in root growth or vitality when growing into the native clay soil. However, when growing into the sandy soil, RTN and the proportion of dead roots were increased by N deposition. Norway spruce fine root N content was also increased in the organic horizon of both soil types. For Scots pine, (NH4)2SO4 treatment caused increased fine root Al content and a decreased Mg/Al ratio in the mineral layer of the sandy soil, with opposite effects in the clay soil. This (NH4)2SO4 treatment effect in the sandy soil for Scots pine was the only indication of a potential adverse effect of (NH4)2SO4 deposition on fine roots. Further results demonstrated the dominant importance of inherent soil characteristics and the stratification into soil horizons on fine root growth and chemical composition. For example, a negative correlation between root biomass and fine root Al content was established for Norway spruce.

International audience

Problems of the environment pollution in Ziarska basin are connected with the operation of Aluminium plant from 1953. After replacement of old production technology by a a new one by Norwegian company Hydro Aluminium emission of dust of Al2O3 dropped from 766 tons per year to 243 tons per year, emission of fluorides dropped from 847 to per year to 65.9 tons per year and of SO2 have increased from 716 to 974 tons per year. The mentioned reduction of emission reflected markedly in a great reduction of vegetation loading by fluorine. In the year 2001 we found statistically sifnificant difference for total Ksupz (coefficient of loading) in coniferous and broadleaved tree species in A polution zone in comparison with the zone B, C and D

The average defoliation of the sites located in the western part significantly increased in 2000, probably as a result of massive needle yellowing and shedding, and the G/A bud ratio decreased for all of the sites what reflected in reduction of crown regeneration. We suppose that a further increase of crown defoliation due to exceedance of stress threshold may trigger tree defensive reactions and replacement of the loss of assimilative organs

Both CO2 and ozone increased the diseased leaf area of clone V5952 in Exp. 1 in the year 2000. The size of spots increased most under ozone fumigation, and the number of spots under ozone and CO2 + O3 fumigations. In clone K1659 all fumigation treatments decreased or had no effect on the DLA, or the number and size of the leaf spots. Also the number of fallen leaves under fumigation treatments was higher in clone V5952 than in clone K1659. Analysis of the year 2001 monitoring results is currently going on

Scientific concern over air pollution impacts on forest health and ecosystem function have evolved from local (point-source), to regional (area source) and ultimately to the global scale (increasing atmospheric CO2). All three scales of investigation remain relevant to increasing our understanding of how air pollution affects forests. Presently, linking air pollution with forest health status through routine monitoring network data remains problematic. In this paper we present a brief overview of air pollutant trends, together with recent European forest condition monitoring and FACE experimental case-study evidence to illustrate the need for multiple-level investigation of air pollutant-forest interactions