| Taking a example of a ecodessetera in the Botalcal Garden, Mt. Lushan underintense acid deposition, both of sulfur chendstry and its dynamics of in forestecosystem was studied by means of field monitoring and sulfur fraction analysis.Both the rooting zone soil and non-rooted soil under different vegetation and indifferent season were smpled, and the fOrest ecosystem resPOnse to aciddeposition was monitored in sitU. The purpOse of this Wor is to describe theecological effects on sulfur distributions of dynamics of the fOrest ecosystem by theacid dePosition and to help enhancement of scientific data for atmosphericdeposition control. The results were as follows:l. The total sulfur in soil of Mt. Lushan was up to 365. l7 t l l5.89mg/kg, of which40.3% being adsorbed sulfuL In the subsurface soil, adsorbed sulfor was l78.82I94.62mg/kg. Whn In-organic sulfur increased, orgboc sulfor decreases, vice versa.Adsorbed sulfur and soluble sulfur in soil under coniferous forest was higher thanthat under deciduous forest, indicating bigger caPacity for adsorbed sulfur of soilunder coniferous forest. In the rooting zone soil under coniferous forest, the totalsulfur soluble sulfur and organic sulfur were higher than tha of none-rooted soil.The roots of coniferous significantlY innuenced distribndon of sulfur fractions.2. The annua decomPOsihon rate of the litters was about 21.l% under coniferousand 24.l% under deciduous. DecomPosition the of deciduous litters were biggerthan that of coniferous litters. DecomPOsition of litters tends to enhance mobile ofsulfur in soils under coniferous foreSt, While increase adsorbed sulfor in soils underdeciduous forest.3. The average sulfate concentraion in precipitation was 2.98mg/L in l998 in thestUdied area. The anntal sulfor dePOsition by preciPitation was l.03kInOU(ha a).Acid rain was greaily buffered by forest canopy, and the canopy of deciduous wasable to bther more acidity of acid taln than canOPy of coniferous. The sulfateconcentration in throughfall and stem-flow were sighficanly higher than that inprecipitation. As comPared with coniferous ecosystem, the inPut of SO4'-deciduous ecosystem was more, while output less.4. The seasonal change pattem of acidity in water Phase and sulfate concefitrationin throughfall and stem-flow were consistent with precipitation, being signiflcanlyhigher in winter than in sununeL Sulfate concentration in throughfail andstem-flow under coniferous fOrest change greatly in differeni seasons. Fractionationof sulfur has apparently seasonal changes. Soluble sulfur was high in spring, andcontent of sulfate in rooting zone soils was higher than that of in non-rooted soil.Organic sulfur accumulated in autumn. In A horizon of soil under coniferous, therewere accumulation of adsorbed sulfate in spring and winter, while in subsoil underdeciduous adsorbed sulfated increase sharply' showing that rootS of deciduousgreatIy improved adsorption of sulfate in soils.5. The chemical coopnent in rain were various during precipitation, and thesulfate dominated the asid dePOsition to eco-system. Ligh rain and rains in auumnmade greater contribution for acid dePOsition. The chemical components inthroughfall aiso changed actively, and had close relationship with charaCer ofprecipitation. The runoff chemical under forest give prompt resPOnd tOprecipitation. During precipitation, pH of runoff declined, While electricity rose.The pH of runoff under deciduous forest was more susceptible than that ofconiferous fOrest, while the electricity of runoff under coniferous fOrest noticeabIyresponded to precipitation pulse effect. After precipitation, the nmoff chemicalunder coniferous forest recovered qulcker than that under deciduous forest. Thechange sulfate concelltr8ion in runoff under deciduous went in a pattem 4 hoursbehind under coniferous forest.In summarize, the sulfur dePOsition fiux in Mt. Lushan was great, andgradually increased.
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