Evaluation of the influence of acid deposition on ecosystems in Cryptomeria japonica forests in snowy mountainous areas adjacent to the Sea of Japan

1.通过测定穿透雨(Tf)和树干径流(SF)化学成分，研究了新泻不同坡位柳杉林中无机物的沉降量。上坡、中坡和下坡的DAS总量分别是降雨的2.35倍、2.40倍和1.70倍。大多数无机成分，特别是来自海盐的沉积，在上坡显著高于下坡，这可能是由于风输送的物质所致。最近气象站的平均风速与DAS(除K~+和含氮化合物外)呈显著正相关，尤其是来自海盐的DAS，与研究区降水量呈显著正相关，特别是在坡度较高的位置。Tf+SF中NH4^+和K^+的DAS可能对冠层相互作用有较大影响。叶片上水滴的接触角(CA)随叶龄的增大而减小，表明表面润湿性随叶龄的增大而增大。Tf中的K+浓度与1年生叶片的CA呈负相关，而NH4+浓度与CA呈正相关。Tf中NH_4~+和NO_3~-的净DAs与CA呈正相关。叶表面润湿性的增加可能会加速K~(++)在林冠上的淋失或氮化合物的吸收。比较了邻近常绿针叶林(CFS)和落叶阔叶林(BF)的溪水化学组成。溪水化学的特点是Cl-和Na~+浓度极高，被认为主要来自海盐。2月下旬至3月中旬，当这个多雪的温带地区在寒冷的雪天后天气好转时，酸休克明显。由于两种森林类型之间的融雪模式不同，这一趋势在森林类型中比在森林类型中更为明显。

1. The deposition amounts (DAs) of inorganic constituents in a Cryptomeria japonica forest were investigated by measuring throughfall (TF) and stemflow (SF) chemistry at different slope positions in Niigata Prefecture. The total DAs at the upper, mid-, and lower slopes were 2.35, 2.40, and 1.70 times higher than that from rainfall, respectively. Deposition of most inorganic constituents, particularly those originating from sea salts, was higher significantly at the upper slope than the lower slope, which may have been due to materials transported by wind. Mean wind velocity at the nearest weather station showed a more significant positive correlation with the DAs (except for K^+ and nitrogen compounds), particularly for those originating from sea salts, than precipitation amount in the study area, especially at higher slope positions.2. The DAs of NH_4^+ and K^+ from TF+SF might have a large effect on canopy interactions. The contact angle (CA) of water droplets on the C japonica leaves decreased with leaf aging, suggesting that surface wettability increases with leaf age. The K^+ concentration in TF was negatively correlated with the CA of one-year-old leaves, while the NH_4^+ concentration was positively correlated with the CA. The net DAs of NH_4^+ and NO_3^-from TF were positively correlated with the CA. The increase in leaf surface wettability may accelerate leaching of K^+ or uptake of nitrogen compounds on the forest canopy.3. Stream water chemistry was compared between neighboring C japonica evergreen coniferous (CFs) and deciduous broad-leaved forests (BFs). The stream water chemistry was characterized by extremely high concentrations of Cl-and Na^+, which were thought to be mostly derived from sea salts. Acid shock was evident from late February to mid-March when the weather improved following cold snowy days in this snowy temperate region. This tendency was clearer in BFs than in CFs due to the different snowmelt patterns between the two forest types.