外來種福壽螺（Pomavea canaliculata）對人工濕地水生植物之攝食偏好：生物控管方法對防治外來種之探討

Feeding Preference of Exotic Snails Pomacea canaliculata on Macrophytes in Constructed Wetland: Implications for Biological Control of Invasive Species

王姿婷(Tzu-Ting Wang) ； 任秀慧(Rita S. W. Yam)

《農業工程學報》 60卷1期 (2014/03) Pp. 42-53

https://doi.org/10.29974/JTAE.201403_60(1).0004

摘要

近年來，人工溼地在台灣各地廣泛興建，為補償因人類利益開發而消失或惡化的自然溼地，以及其提供的多項生態系統功能如淨化水質、防洪蓄水、調節氣候、提供野生生物棲地及人類休憩場所等。然而，因人工溼地因承接鄰近社區的生活污水及河川流域的入流水，這成為了外來種福壽螺（Ampullariidae: Pomacea canaliculata）入侵人工溼地的主要途徑，目前福壽螺已普遍入侵台灣人工溼地，並大量攝食其中水生植物，大幅降低人工溼地的去污效能，嚴重影響其中生物多樣性及生態系統服務。本研究假設福壽螺對不同種類水生植物具有攝食偏好，而攝食不同水生植物後會影響福壽螺的成長反應（生物量及殼長）。本實驗選取三種人工溼地常見的水生植物，分別為空心菜（Ipomoea aquatica）、菖蒲（Acorus calamus）、蘆葦（Phragmites australis），依據福壽螺對不同水生植物的攝食量評估其攝食偏好，並分析攝食不同植物後的成長參數，從而確定有效控制福壽螺拓殖的水生植物種類。本實驗依據福壽螺的攝食量及成長率（生物量及殼長成長量），證實空心菜為福壽螺攝食偏好最高的水生植物。此外，福壽螺對老蘆葦和菖蒲的攝食偏好同樣偏低，其成長率（包括乾重成長率、殼長成長率、生物量及殼長變化）顯著緩慢。最後我們比較線性迴歸結果，確定攝食菖蒲福壽螺的成長率為三種實驗水生植物中最低。因攝食菖蒲最不利於福壽螺成長，菖蒲對控制福壽螺入侵人工溼地實在具有潛在的重要性。本研究未來將進一步探討不同種類的水生植物化學和物理性質，配合本研究結果作分析比對，以了解福壽螺攝食不同種類水生植物的原因。我們將繼續探討藉上行生物控管方法防治福壽螺拓殖，在未來建置同時兼具去污效能及控制福壽螺拓殖的人工溼地，建立植物群集種植及管理的參考標準。

關鍵字

人工溼地 ； 福壽螺 ； 水生植物 ； 攝食偏好 ； 生物控管

並列摘要

Constructed wetlands are widely developed in Taiwan to compensate the lost and degraded natural wetlands due to human impacts and simulate the natural wetlands to provide many different ecosystem services such as water purification, climate regulations, wildlife habitat, and human recreation. However, biological invasion has become a serious threat in constructed wetland ecosystems because of their relatively low habitat stability and complexity. Nowadays, exotic apple snails (Ampullariidae: Pomacea canaliculata) have invaded most of the constructed wetlands in Taiwan and caused serious problems to the ecosystem including lowering the wastewater purification efficiency by extensively feeding on the macrophytes, competing with the native gastropods, and causing visual impacts due to their over-dominance in the constructed wetland habitats.In this study, we hypothesized that apple snails had different food preference on different macrophyte species and produced different growth responses correspondingly. We conducted laboratory feeding experiment to study the growth responses of apple snails upon feeding on 3 common wetland macrophytes including Ipomoea aquatica, Acorus calamus, and Phragmites australis. Results from ANOVA and Tukey Test showed that I. aquatica supported the highest growth rate of snails in terms of shell length and biomass increment. Pomacea canaliculata demonstrated significantly lower feeding preference on A. calamus and P. australis. However, results from regression analysis indicated that snails feeding on A. calamus showed the lowest growth rates. We therefore suggested that A. calamus would have the potential importance in controlling the establishment of P. canaliculata to the constructed wetlands.Our future work will involve analysis of the chemical and physical properties of macrophyte leaves to assess the relationship between food quality and food preferences of the apple snails. Our results could therefore provide implications for macrophyte planting in constructed wetlands as biological control measure of the invasive snails based on the bottom-up biomanipulative approach instead of applying traditional methods such as using pesticides or labor-intensive physical removal.

並列關鍵字

constructed wetlands ； apple snails ； macrophytes ； feeding preference ； biomanipulation