透過生態聲學技術揭開都市綠地之直翅目昆蟲鳴叫多樣性

Abstract

生態聲學技術被認為是可靠且非侵入性的多樣性調查方法，然而過去研究主要專注於脊椎動物，許多發聲的直翅目昆蟲，例如蟋蟀與螽斯，則較少被討論。隨著都市的擴張，都市環境中昆蟲的保育與研究也漸趨受到重視。本研究探討都市綠地中直翅目昆蟲的鳴叫多樣性與族群變動，並評估六種常用聲音指標（acoustic indices）在預測鳴叫昆蟲多樣性上的適用性。此外，亦探討物種組成與棲地間的相關性。我們使用錄音機（16-bit WAV，取樣頻率達 44.1 kHz）在九個都市綠地進行監測，每月錄製三天，持續一年，並量測環境因子，分析鳴叫出現次數與多樣性。研究結果顯示，物種對棲地的偏好可由聲景資料反映，且多項環境因子與鳴叫多樣性呈正相關，推測具較高棲地異質性的地點可能支持更多樣化的直翅目昆蟲群聚。此外，比較不同月份間的聲音資料亦能呈現部分物種的族群變動趨勢。在聲音指標中，Bioacoustic Index（BI）與 Normalized Difference Soundscape Index（NDSI）與物種多樣性呈現最強正相關，而 Acoustic Complexity Index（ACI）表現最差。基於上述發現，本研究展現生態聲學方法於生物多樣性監測上的應用潛力，並強調小尺度環境因子對直翅目多樣性的影響，為都市綠地設計提供相關科學依據與建議。

The ecoacoustic method is a reliable and non-invasive approach for investigating biodiversity. While previous biophony research has primarily focused on vertebrate animals, many sound-producing Orthoptera insects, such as crickets and katydids, remain underexplored. As urbanization accelerates, understanding and conserving insect diversity in urban environments has become increasingly important. This study explores the diversity and population dynamics of orthopteran soundscapes in urban green spaces and evaluates the utility of six acoustic indices in estimating the richness of chirping insects. Nine grassland sites were monitored using sound recorders (16-bit WAV, frequency response up to 44.1 kHz), recording for three days each month over a one-year period. Environmental variables were also measured to assess their associations with calling insect diversity. The recordings were analyzed to determine the occurrence and diversity of calling patterns. Our results indicate clear species-specific habitat preferences, and several environmental variables were positively associated with chirping insect diversity, suggesting that sites with greater habitat heterogeneity may support more diverse communities. Furthermore, acoustic data revealed population dynamics across different months in some species. Among the acoustic indices, the Bioacoustic Index (BI) and Normalized Difference Soundscape Index (NDSI) showed the strongest correlations with species richness, while the Acoustic Complexity Index (ACI) was the least effective. Based on these findings, this study demonstrates the ecoacoustic method can be effectively applied to biodiversity monitoring and highlights the importance of local environmental factors in shaping orthopteran richness. These results also provide insights for enhancing insect conservation in the planning and development of urban green spaces.