遊客踩踏行為對岩岸潮間帶附著生物的影響

本研究於北海岸三芝區淺水灣的岩岸潮間帶上，進行遊客踩踏模擬實驗，來探討遊客踩踏行為對潮間帶岩岸附著生物的衝擊。選取安山岩及藻礁岩石平台各十處，每處平台設置三個樣方，從2010年6月到11月每個月初進行踩踏施予不同強度的踩踏（每個月每100平方公分踏0下、125下、500下）。並於踩踏月份的月末進行生物調查，及停止踩踏之後的1個月與3個月觀察生物相的恢復狀況。結果發現，每個月踩踏500下之樣方，在踩踏3個月後出現各種生物豐度皆較控制組低50%的情況。附著動物對踩踏影響較紅藻類敏感。附著動物受踩踏後數量立即減少，但停止踩踏後即恢復；紅藻類則是踩踏三個月後才受影響，但停止踩踏實驗後仍難恢復。人類踩踏海岸岩石可直接及間接干擾原有的潮間帶生態系，如經踩踏後紅藻類難恢復的情況下，導致與其存在空間競爭關係的石蓴（Ulva lactuca）覆蓋率增加。

關鍵字

臺灣北海岸；遊客踩踏；附著生物

並列摘要

This study performed a trampling experiment at Qianshui bay of Sanzhi township in the North coast of Taiwan to investigate effects of human trampling on attached organisms in intertidal rocky shore. We selected two types of rocky intertidal platforms, and esite rock and algal reef, in the North coast of Taiwan. There are ten rocks for each rock type and there are three types of quadrats with different trampling treatments on each rock. The trampling experiment was used 0, 125 or 500 footsteps per 100 cm2 per month on different treatment quadrats for each rock from June 2010 to November 2010. Observations were made on attached organisms at the end of each month during trampling treatment as well as 1 and 3 months after the last of trampling treatment. We found that all kinds of organisms reduced to 50% of control values at 500 footsteps per month after three months of the trampling treatment. Attached animals are more sensitive to trampling effects than red algae. Attached animals declined immediately after trampling started, but they recovered at the end of trampling treatments. By contrast, red algae were resistant to trampling effects in first three months of trampling, but they could not recover after the experiment. Human trampling can cause both direct and indirect effects on intertidal ecosystem. For example, percentage cover of sea lettuce (Ulva lactuca) increased after trampling because red algae are difficult to recover from trampling treatments, which compete for settlement space with sea lettuce.