水土保持工程对水生萤火虫(黄缘萤)之影响

Influence of Soil and Water Conservation Structure on Aquatic Firefly(Luciola ficta)

以台湾南部屏东地区的黄缘萤栖地为研究对象,调查栖地水质环境并探讨水土保持工程(景观护岸)对黄缘萤之影响。调查结果显示:该地区的水质环境相当适合黄缘萤的生存,黄缘萤繁殖的两个高峰期分别为11月与6月,且黄缘萤求偶的高峰期约在日落后1h。土堤护岸黄缘萤数量为景观护岸的三倍以上,造成此差异的原因主要为景观护岸的设计并未考虑黄缘萤的成长及繁衍过程,所以造成影响。因此水土保持工程的设计与施作,必须考虑当地生物习性才能降低对生物栖地的破坏,以免影响生态保育。

In the 1950s,Luciola ficta was abundant in Taiwan＇s rural ecosystems.Since then,its field habitats have decreased rapidly due to agrichemical toxicity,light pollution,and habitat destruction caused by the cementing of irrigation ditches.The work presents the investigation of water quality on its field habitat and discussion about the influence of soil and water conservation structure（landscape revetment） on its number in Pingtung County of southern Taiwan.The result shows that the water quality of field habitat is suitable for the living of L.ficta.Two peak values of activity for adult L.ficta occur in November and June,and the most values of L.ficta appear after sunset 30～60 min.The number of adult L.ficta measured on soil revetment equaled about 3 times of which measured on landscape revetment.On the other hand,the soil and water conservation structure has quite obvious influence on L.ficta habitat.Therefore,the process for design and construction of soil and water conservation structure must take care of the field habitat of organism and reduce the habitat destruction.