Conservation of Water Environment and Vegetation in Mire

本研究旨在评估人类活动对泥沼地下水水质和植被的影响，如水体栽培系统的变化，并提出泥沼的保护系统。我们选择了典型的Sarobetsu泥潭和Kiritappu泥潭。以北海道沼泽为研究对象。1997 ~ 1998年共调查了Sarobetsu 7次，Kiritappu 6次。Sarobetsu沼泽的植被被破坏了。第二次世界大战后通过排水和建造农田，而其余的沼泽则因入侵莎莎而处于存在的危险之中。克里塔普沼泽的演变过程与萨罗别苏沼泽相似。研究了沼泽及其周边地区的地下水、河流、湖泊水质、泥炭草和莎草的土壤组成和生长状况。根据资料，我们发现人类活动影响了沼泽的生命。研究发现，从泥炭中抽干水，使地下水位降低，泥炭土变干，泥炭土分解导致养分浓度升高，开发混合土壤使磷和硅酸含量增加。成分的变化似乎影响植物的生长状态。在Sarobetsu泥潭中，排水导致莎草入侵，泥炭土分解导致无机养分增加，促进莎草生长。为了抑制以莎草为代表的异种植物进入泥沼，有必要对泥沼外来入侵进行控制。

This study is to estimate the influences of human activities to ground water quality and vegetation of mire, such as changes of water cultivation system and to propose the conservation system of mire. We chose Sarobetsu Mire and Kiritappu Mire, typical. mire of Hokkaido as subjects of the study. We surveyed Sarobetsu 7 times and Kiritappu 6 tomes from 1997 to 1998. Vegetation of Sarobetsu Mire has been destroyed .by draining and building farmland after World War II, and the rest of mire is in peril of existence by invasion of Sasa. Kritappu Mire is changing in similar course of development as Sarobetsu Mire. We researched water quality of ground water, rivers and lakes of the mire and surrounding area, soil composition and growing state of Sphagnum and Sasa. According to the data, we found that human activities affects life of mire. We found that by draining water from mire, ground water level lowers and peat soil gets dry, concentration of nutrients arises by decomposition of peat soil, and mixing soil by exploitation increases amount of phosphorus and silicic acid. The change of composition seems to influence the growing state of plants. In Sarobetsu Mire, drainage leads Sasa to invade causing increase of inorganic nutrients as peat soil decomposes, and promote Sasa to grow. It is necessary to check matters to invade from outside of mire in order to restrain heterogeneous plants as Sasa as a typical one to get into mire.