- 學位論文
貧營養集水區中浮游生物體型大小和環境因子對食階能量傳遞效率之影響
Influences of Body Sizes and Environmental Changes on Trophic Transfer Efficiency of Plankton in an Oligotrophic Reservoir
若您是本文的作者，可授權文章由華藝線上圖書館中協助推廣。
摘要
貫穿整個浮游食物鏈的營養轉移效率（Trophic Transfer Efficiency, TTE）是較高營養水平的主要能量來源，受到多種因素的影響。 貧營養水庫中浮游植物和浮游動物之間的 TTE 趨於增加並表現出高度的變異性。 環境變化和不同體型物種之間的相互作用可能會導致 TTE 的改變，但這些研究普遍不足。 本研究旨在透過原位調查，綜合分析環境因素和物種體型兩個重要因素如何影響貧營養水庫中浮游植物和浮游動物之間物質的TTE（能量或碳和氮），分三章進行闡述。 第一章研究了熱帶氣旋（TC）經過期間（第一部分）和溫暖和寒冷時期（第二部分）環境因素對2 m深度的能量TTE（生物量的代表，TTEe）的影響。 第二章分析了尺寸分級的浮游植物和浮游動物的TTE之間的差異，以及溫暖和寒冷時期水溫如何影響TTE。 第三章研究了獵物（即POM 和44-74 μm 尺寸分級的浮游動物）和尺寸分級浮游動物（即>500 μm 和74-177 μm 尺寸）之間碳(C) 和氮(N) 的TTE有何不同,以及水溫和無機營養如何影響變異。2012年1月至2021年6月，在翡翠水庫（Fei-Tsui Reservoir, FTR）進行了密集的原位採樣，研究浮游生物體型和環境因素對浮游植物和浮游動物材料TTE的影響。 第一章第一部分的結果表明，受水溫影響，TTEe在溫暖時期顯著降低，在寒冷時期顯著增加。第一章第二部分表明，在熱帶氣旋週期間，TTEe隨著水溫和NO2- 濃度的升高而增加，而在緩慢移動的熱帶氣旋事件期間，TTEe減少。 快速移動的 TC 與較高的 NO2- 濃度和較低的 NO3- 濃度相結合，增強了 TTEe。第二章的結果表明，尺寸分級的浮游植物和浮游動物之間的TTEe存在顯著差異，並且發現從奈米浮游植物輸送至微型浮游植物時, TTEe變得更大。在所研究的各種浮游生物大小組別中，觀察到僅微型浮游植物和中型浮游動物（> 500 μm 和177-500 μm）之間的能量TTE 在受較高溫度負面影響的暖期和冷期之間表現出相當大的變化。 第三章的結果表明，POM與>500μm尺寸分級浮游動物之間的碳TTE（TTEc）在寒冷時期顯著增加，而氮TTE（TTEn）在溫暖和寒冷時期保持恆定。 44-74 μm 和 74-177 μm 大小分級浮游動物的 C 和 N TTE 在溫暖和寒冷時期保持在較高水準。 POM與74-177μm浮游動物之間的C和N TTE在溫暖和寒冷時期保持較低水準。 這些發現表明，不同體型的浮游生物的 C 和 N TTE 表現出差異。對 POM 和 > 500 μm 尺寸分級之間的 TTEc 的進一步分析表明，TTEc 與水溫和全柱平均 PO43- 濃度呈負相關（0-90 m 深度），與透光深度平均（0-15 m 深度）及全柱平均NO2- 濃度呈正相關。本論文強調環境因素（主要是水溫和無機營養鹽）以及浮游生物的體型大小會影響貧營養水庫中浮游植物和浮游動物之間物質的TTE。 由於浮游生物在水生食物鏈中發揮重要作用，並且對環境變化敏感，因此了解浮游生物營養級之間的 TTEc 如何隨時間變化非常重要，因為它反映了生態系統中的物質流動。
並列摘要
The trophic transfer efficiency (TTE) throughout the planktonic food chain, which is the main source of energy for higher trophic levels, is influenced by various factors. TTE between phytoplankton and zooplankton in oligotrophic reservoirs tends to increase and show high variability. Environmental changes and interactions between species with different body sizes potentially lead to alteration of TTE, but these are generally understudied. This study aimed to comprehensively analyze two considerable factors, such as environmental factors and species body sizes, influencing TTEs of materials (e.g., energy or carbon and nitrogen) between phytoplankton and zooplankton in an oligotrophic reservoir through in situ investigation, presented in three chapters. The first chapter examined the influences of environmental factors on the TTE of energy (a proxy for biomass, TTEe) at 2 m depth in warm and cold periods (first part) and during tropical cyclone (TC) passages (second part). The second chapter analyzed how TTEs of energy differ between size-fractioned phytoplankton and zooplankton and how water temperature affects the TTEe in warm and cold periods. The third chapter investigated how TTEs of carbon (C) and nitrogen (N) differ between prey (i.e., POM and 44-74 μm size-fractioned zooplankton) and consumer zooplankton (i.e., >500 μm and 74-177 μm size-fractioned zooplankton) and how water temperature and inorganic nutrients influence the variability. An intensive in situ sampling was conducted in Fei-Tsui Reservoir (FTR) from January 2012 to June 2021 to study the influences of plankton body sizes and environmental factors on TTEs of materials between phytoplankton and zooplankton. The first part of the first chapter showed that the TTEe was significantly decreased in warm periods and increased in cold periods, influenced by the water temperature. The results in the second part of the first chapter showed that, during a TC week, TTEe increased with higher water temperature and NO2- concentration, while it decreased during slow-moving TC events. The combined effects of a fast-moving TC, along with higher NO2- concentration and lower NO3- concentration, enhanced TTEe. The results of the second chapter revealed that TTEe significantly varied between size-fractioned phytoplankton and zooplankton, and it was found to be greater when transported from nanophytoplankton than microphytoplankton. Among the various plankton size groups studied, it was observed that merely TTEs of energy between microphytoplankton and mesozooplankton (>500 μm and 177-500 μm) exhibited considerable variations between warm and cold periods negatively influenced by higher temperature. The results of the third chapter showed that TTE of carbon (TTEc) between POM and >500 μm size-fractioned zooplankton increased significantly in cold periods, and TTE of nitrogen (TTEn) remained constant in both warm and cold periods. The TTEs of C and N between 44-74 μm and 74-177 μm size-fractioned zooplankton remained high in warm and cold periods. The TTEs of C and N between POM and 74-177 μm size-fractioned zooplankton remained low in warm and cold periods. These findings indicate that plankton of different body sizes exhibited variations in their TTEs of C and N. Further analysis on TTEc between POM and >500 μm size-fractioned zooplankton revealed that TTEc had negative relationships with water temperature and whole column-averaged PO43- concentration (0-90 m depth), and it had positive relationships with euphotic depth-averaged (0-15 m depth) and whole column-averaged NO2- concentrations. This thesis highlights that environmental factors, such as water temperature and inorganic nutrients, and plankton body sizes impact the TTEs of materials between phytoplankton and zooplankton in an oligotrophic reservoir. Since plankton play an important role in the aquatic food chain and are sensitive to environmental changes, it is important to understand how TTE between plankton trophic levels changes over time because it reflects the material flows in the ecosystem.
參考文獻
Akima, H., and Gebhardt, A. (2022). Akima: Interpolation of Irregularly and Regularly Spaced Data. R package version 0.6-3.4. https://CRAN.R-project.org/package=akima
Allen, C.D., and Breshears, D.D. (1998). Drought-induced shift of a forest-woodland ecotone: Rapid landscape response to climate variation. PNAS, 95, 14839-14842.
Alvarez-Cobelas, M., and Rojo C. (2000). Ecological goal functions and plankton communities in lakes. J Plankton Res, 22(4), 729-748. https://doi.org/10.1093/plankt/22.4.729
Andersen, T., and Hessen, D. (1991). Carbon, nitrogen, and phosphorus content of freshwater zooplankton. Limnol Oceanogr,36(4), 807-814. https://doi.org/10.4319/lo.1991.36.4.0807
Armengol, L., Calbet, A., Franchy, G., Rodríguez-Santos, A., and Hernández-León, S. (2019). Planktonic food webs structure and trophic transfer efficiency along a productivity gradient in the tropical and subtropical Atlantic Ocean. Sci Rep, 9, 2044. doi:10.1038/s41598-019-38507-9