Effects of Human Activity on Water Enviroument of Mire

在北海道，我们仍然有许多沼泽地，特定的植物生长在那里。它们正因人类活动而逐渐消失。在Sarobetsu和Tsukiga-Umi Mire，我们对沼泽中地下水的水质进行了研究，并研究了在自然条件下维持沼泽的水栽培制度。结果表明：(1)隆起沼泽地下水水质独特，有机质含量高，腐植酸含量高，pH值低，平均为4.8。(2)隆起沼泽上层地下水中常见无机物含量低，组成与雨水相似。(3)在高沼泽区(Sphgnum Moss Area)，由于营养物质浓度低且以有机养分为主，分解活性极低。(4)Sarobetsu Mire高水位区营养状态为贫营养，低水位区营养状态为富营养化，无机形态氮占主导地位。(5)在竹草入侵区，有机物浓度与溶解氮(尤其是无机氮)浓度呈正相关。在低水位下，营养盐处于易被细菌分解的状态。(6)当竹草入侵时，铁和硅酸盐的浓度增加。不应忽视地质特征的影响。

In Hokkaido, we still have many mire fields where specific plants grow. They aregradually disappearing by human activities. We resarched the quality of ground water in the mire and studied the water cultivation system that maintains the mire under the natural condition at Sarobetsu mire and Tsukiga-Umi Mire. The results are summerized as follows ;(1) The ground water quality of rised bog is in a unique circumstance, with high concentration of organic matters composed of humic-acid and with low pH,4.8 on the average.(2) In tne ground water of the upper layr of the raised bog, the concentration of the common inorganic components is low and the composition is similar to rain water. It is absolutely necessary to cultivate the ground water by rain water to maintein the natural mire.(3) In the region of raised bog (Sphgnum moss area), the decompositon activity is extremely low as the concentration of nutrients is low and the organic nutrients are dominant.(4) While nutrient state of the high water level region of the Sarobetsu Mire is oligotrophic, that of the low ground water level region is eutrophic where inorganic form of nitrogen is dominant.(5) In the region where bamboo grass invades, the concentration of organic matters and that of dissolved nitrogen (especially inorganic nitrogen) have a positive relationship. Nutrients are in a state liable to dissolve by the bacterial decopositon under the low level of ground water.(6) Where bamboo grass invades, the concentration of Iron and Silicate increases. Influences of geological features should not be disregarded.