本文關鍵詞： 缽水母 生活史 暴發(fā)機理 沙蜇 橫裂 基質 PM模型 CPM模型 海洋食物網模型　出處：《東北師范大學》2017年博士論文　論文類型：學位論文

【摘要】：近年來,水母暴發(fā)給人們的生產生活及海洋生態(tài)系統帶來嚴重影響,成為繼有害藻華之后最大的海洋生態(tài)災害.水母數量激增源于它復雜的生活史,對于大多數缽水母而言,沒有了海底水螅體的補充,再適宜的理化生環(huán)境都與其無關,海底水螅體的存在是水母暴發(fā)的充分條件.建立和研究水母生活史模型是揭示水母暴發(fā)機理的第一步也是關鍵一步.本文重點研究受理化環(huán)境影響的缽水母生活史模型,通過定性分析及數值模擬揭示橫裂、萌發(fā)等關鍵過程對水母生活史各階段的影響以及誘發(fā)水母數量激增的關鍵環(huán)境因子;在此基礎上建立水母與浮游生物及魚類的食物網模型,討論各功能群與水母暴發(fā)的內在聯系,揭示海底階段對水母暴發(fā)及整個浮游生態(tài)群落的影響.本文首先給出了一般的缽水母生活史模型(PM模型),討論了溫度、天敵及基質變化對水母種群的影響.相比于天敵的減少,系統對海底基質的擴張更加敏感,海底階段對種群數量的激增具有重要貢獻;在一定范圍內,溫度增加將導致水媳體和水母數量增加,但過高的溫度對二者都是有害的.本文隨后研究了嚴重困擾東亞海域的巨型水母——沙蜇的生活史模型(CPM模型),為了揭示足囊休眠與萌發(fā)對沙蜇種群的影響,先后建立了常數時滯、分布時滯及考慮海底密度制約效應的泛函微分方程模型.研究表明隨著足囊休眠時間的增加,系統經歷Hopf分支從穩(wěn)定到振蕩;足囊的波動可引起水螅體的波動,但對水母體影響不大.文中結合大連附近海域表層水溫的數據變化,指出溫度和休眠時間共同影響足囊的數量變化;足囊的休眠與萌發(fā)不應成為水母暴發(fā)的關鍵因素.參數敏感性分析刻畫了水螅體對基質擴張最為敏感,而水母體數量受橫裂率影響最明顯.此外,控制近海人為基質的擴張,可以避免海底階段生活空間的提升,從而避免溫度增加所引起的橫裂率增加,同時降低浮浪幼體的存活率,增加水螅體的競爭率,進而降低沙蜇各階段的數量,是有效可行的控制策略.水母大范圍暴發(fā)是一個不爭的事實,目前爭論的焦點在于水母的增加是一種趨勢?還是僅僅為一種周期性振蕩?本文在最后建立了基于水母生活史的四維食物網模型,分析指出橫裂率的增加并不總是對水母有利;藻類大量聚集將引起水母數量的增加;當控制橫裂率,同時適當降低藻類增長率時,不僅水母數量可以得到控制,魚類資源也可以得到恢復.數值分析不僅展現了水母數量的周期性振蕩,而且給出了保護和恢復魚類資源的控制策略.本文通過數學模型,刻畫水母生活史,揭示環(huán)境因子對生活史各階段的影響、關鍵過程和暴發(fā)機理;并將生活史耦合進食物網模型中,揭示生活史的關鍵過程對水母暴發(fā)的影響、藻華與水母暴發(fā)的內在聯系、以及水母暴發(fā)對魚類及整個海洋生態(tài)系統的影響.通過本文的研究,我們試圖為水母暴發(fā)的機理研究提供新的模型和研究思路,為控制水母暴發(fā)及魚類資源恢復提供相應的理論策略.
[Abstract]:In recent years, jellyfish bloom bring serious influence to the production and life of people and the marine ecosystem, become marine ecological disaster after the harmful algal blooms. The largest jellyfish due to the surge in the number of its complex life history, for most scyphozoan, no added submarine polyps, and appropriate physical and chemical environment and regardless of the existence of submarine hydra is a sufficient condition for the establishment and research of jellyfish bloom. The jellyfish life history model is the first step to reveal the mechanism of jellyfish bloom is a key step. This paper focuses on the acceptance of scyphomedusae life history model of environmental impact, through qualitative analysis and numerical simulation of transverse crack, the key influence on the germination process each stage of jellyfish life history and jellyfish induced surge in the number of key environmental factors; on the basis of the establishment of jellyfish and plankton and fish food web model, discuss the work Can the internal contact group and jellyfish bloom, reveal the effect of submarine stage of jellyfish bloom and the planktonic ecological community. This paper first gives the scyphomedusa life history general model (PM model), discussed the effect of changes in temperature, natural enemies and matrix on the jellyfish population. Reduce compared to natural enemies, the system is more sensitive to expansion submarine matrix, submarine stage has an important contribution to the surge in population; in a certain range, the temperature will lead to increase the quantity of water body and daughter-in-law jellyfish increased, but the high temperature is harmful to the two. This paper studied the life history model of mega - nemopilema nomurai plagued the East Asian sea jellyfish (CPM model), in order to reveal the Podocyst effect on Dormancy and germination of nemopilema nomurai population, has established a constant time delay, distributed delay and functional differential equation model of submarine density. The results show that with the consideration of the effect Increase the Podocyst sleep time, the system undergoes a Hopf bifurcation from steady to oscillatory; Podocyst fluctuations can cause polyp fluctuations, but has little effect on Medusa. Combining near Dalian sea surface temperature data changes in the text, pointed out that the temperature and time effect of changes in the number of dormant common Podocyst; Podocyst dormancy and should not become a key factor in the germination of jellyfish blooms. The sensitivity analysis of parameters characterize the polyp was most sensitive to the matrix expansion, and the number of Medusa by the cross crack rate is the most obvious influence. In addition, the offshore artificial control matrix expansion, can avoid the bottom stage of life space, so as to avoid the temperature caused by the increase of the transverse crack the rate of increase, and reduce the survival rate of planula, increase polyp competition rate, thereby reducing the number of stages of nemopilema nomurai, the control strategy is feasible and effective. A wide range of jellyfish outbreaks is an indisputable The fact that the focus of the debate in the increase of jellyfish is a trend? Or just a periodic oscillation? At the end of this paper established a four-dimensional food web model of jellyfish life history based on the analysis pointed out that the transverse crack rate increase is not always favorable to jellyfish; algae aggregation will lead to increased number of jellyfish; when control of transverse crack rate, lowering the algae growth rate, not only the number of jellyfish can be controlled, fish resources can also be restored. Numerical analysis not only shows the periodic oscillation of the number of jellyfish, and presents the control strategy of the protection and restoration of fish resources. Through the mathematical model, describe the jellyfish life history, revealing the environmental factor effects of the various stages of the life cycle and the key process and outbreak mechanism; and the life history of coupled into the food web model, reveals the key processes affecting life history of jellyfish outbreaks, Relationship of algal blooms and jellyfish bloom, and jellyfish bloom effect on fish and the marine ecosystem. Through this research, model and provide new research ideas for mechanism research we try to provide the theory of jellyfish blooms, the corresponding strategies to restore control of jellyfish blooms and fish resources.

【學位授予單位】：東北師范大學
【學位級別】：博士
【學位授予年份】：2017
【分類號】：O175

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本文編號：1519165