凉水国家级自然保护区溪流水化学特征分析

Hydrochemical analysis of characteristics of stream flow in Liangshui National Nature Reserve

采用集水区对比分析方法，探讨凉水国家级自然保护区不同森林类型对溪流水化学特征的影响。结果表明：保护区内各集水区溪流水均呈弱酸性至中性；主要离子中阳离子均以Ca^2＋的质量浓度最高，Na^＋次之，阴离子均以HCO3^-的质量浓度最高，SO4^2-次之；不同集水区溪流水中TP月平均质量浓度为0．031—0．077μg/L，TN为0．682-0．942mg／L，NO3^-N的质量浓度高于NW4^＋-N；Fe的月平均质量浓度为0．030-0．037mg／L，Mn为0．010～0．012mg/L。溪流水化学季节变化规律表现为：除HCO3^-、SO4^2-、Ca^2＋、Fe和Mn外，其他元素在融雪期（4、5月）含量均较高；大多数元素在雨季的质量浓度比9月份低，而TN、TP、Fe、Mn表现为9月份的质量浓度低于雨季。保护区内原始阔叶红松林集水区溪流水质为最优，其他研究集水区溪流中的溶解物质含量增高，但除TP和SO4^2-（P〈0．05）外，差异性均不显著。说明凉水国家级自然保护区内虽进行过森林采伐和人工造林等人为干扰，但对于溪流水质并没有显著影响。

The effects of forest types on hydrochemical characteristics of streams in Liangshui National Nature Reserve were studied by the comparison experiment of watersheds. The results show that the stream flow of each watershed in reserve is weak acidic or neutral. Ca^2＋ is the most abundant cation followed by Na^2＋ in these streams. In the case of anions, HCO3^- presents the highest concentration and followed by SO4^2- . The monthly mean concentrations of TP in stream flow present from 0.031 - 0.077 mg/L, and that of TN vary from 0.682 - 0. 942 mg/L. The concentration of NO3^- -N is higher than that of NH4^＋ -N. The monthly mean concentrations of Fe and Mn are 0.030 - 0.037 mg/L and 0.010 - 0.012 mg/L, respectively. The seasonal variation of hydrochemical characteristics of streams indicate the relatively high ion concentrations during snowrnelt period （April and May） except for HCO3^- , SO4^2- , Ca^2＋ , Fe and Mn. Apart from TN, TP, Fe and Mn, the concentrations of other major elements in September are higher than that in rainy season. The streams flowing through the watershed of primitive Pinus koraiensis and broad-leaved climax forest show the best water quality. The expansion of manmade forest and secondary forest in other researched watersheds result in the increase of the soluble matter in the stream flow, however, there are no significant differences except for TP and SO4^2- （p〈0.05）. This results indicate that the influences of artificial disturbances （e. g. forest harvesting or reforestation） on the water quality of the stream flow in Liangshui National Nature Reserve are not significant.