黃緣螢棲地復育之調查–以臺北市大安森林公園為例

Abstract

在都市重現消失物種的蹤跡，是現代生態棲地營造的重要課題。本研究主要探討黃緣螢 (Aquatica ficta (Olivier, 1999)) 在都市中的復育棲地，與其環境因子關係，並於臺北市大安森林公園進行水文、水質、植栽、微氣候和黃緣螢成蟲數量調查。大安復育樣區分兩階段施工：第一階段為2015年9月中至2015年11月初，棲地面積375 m²，水域面積170 m²；第二階段為2016年7月初至2016年10月初，面積增至2,555 m²，水域面積480 m²。樣區水域的平均水深為20.55 cm (±6.84)，平均溶氧4.95 mg/L (±1.72)，為黃緣螢幼蟲適合棲息的水質狀態。自2016年5月至2017年8月，樣區成蟲發生期為3月至11月，高峰期為5月。相較於一般白光路燈，590 nm路燈雖然對於成蟲分布的影響較少，但照明強度仍有影響。成蟲在樣區微氣候的選擇，較偏好氣溫20~32 °C，相對溼度65 %以上，風速0.1 m/s以下和照度1 lux以下的範圍。當微氣候在一定的範圍內，成蟲於棲地分布的氣溫較都市氣溫低，公式為y = 0.8634 x + 2.3144；相對溼度則較都市相對濕度高，公式為y = 0.6891 x + 32.215。根據結果可知，在都市中復育螢火蟲棲地，需使用溶氧量充足的自然水體，搭配螢火蟲棲息的微氣候條件，選植本土原生種植栽，而低風速和低光照是必要營造。由於調查時間僅為16個月，對於樣區是否復育成功，尚無法定論。

Reappearance of disappeared species in the city is an important issue of constructing ecological habitats nowadays. This study mainly explored the effect of Aquatica ficta (Olivier, 1999) habitat restoration in urban areas, and its environmental impact factors. The research was done on a regular basis for hydrology, water quality, plantation, microclimate surveys, and the number of the firefly observed in Daan Forest Park (Taipei). The habitat restoration of A. ficta (Olivier) in Daan was divided into two stages. The first stage was from mid-September 2015 to early November 2015, with an area of 375 m²; water area of 170 m ²; the second stage was from early July 2016 to early October 2016, with the expansion of the area to 2,555 m², water area of 480 m². The average water depth of wetland was 20.55 cm (±6.84) and the average dissolved oxygen was 4.95 mg/L (±1.72), which meant a suitable habitat environment for the larvae. From May 2016 to August 2017, the adults appeared from March to November, and the peak is May. Compared with the general white street lights, the 590 nm street lights had less effect on the distribution of the adults, but the illumination still had its influence. The adults preferred temperatures 20~32 °C, relative humidity above 65 %, wind velocity below 0.1 m/s and illumination below 1 lux in the microclimate. When the microclimate is within a certain range, the temperature distribution of the adults in the habitat is lower than the urban temperature, and the formula is y = 0.8634 x + 2.3144; while the relative humidity is higher than the urban relative humidity, and the formula is y = 0.6891 x +32.215. According to the results, using natural water with enough dissolved oxygen, planting native plants to match with the microclimate, and low wind velocity and low illumination are the key constructions for firefly habitat restoration in the city. As the investigation lasted for only 16 months, there was no conclusion as to whether the habitat was successful or not.