非生物因子对外来浮游植物入侵影响的模型研究

A great volume of ballast water discharge from ocean ships in the sea area of ports is one of the important factors which cause the spread of aquatic non-indigenous phytoplankton isolated geographically by water and the frequent outbreaks of red tides. In this project, models of population dynamics are established to examine the effect of abiotic factors on the invasion of non-indigenous phytoplankton. An ecological reproductive index is defined to characterize reproductive capacity of invasive phytoplankton. Effect of temperature, seasonal climate change, phosphorus-carbon ratio on the invasion of non-indigenous phytoplankton is analyzed systematically. The invasion threshold analysis is applied to explore the competition between the indigenous phytoplankton and the non-indigenous phytoplankton and determine relations between environmental conditions and phytoplankton composition. Scientifically strategies of discharging ballast water is formulated based on the invasion threshold value of non-indigenous phytoplankton. This project provides both a method of risk assessment of invasive phytoplankton based on dynamic modeling and basis for the risk assessment and management of the non-indigenous marine organism invasion.

远洋船舶压载水在港口海域的交替排放是造成地理性隔离水体间外来海洋浮游植物传播和赤潮灾害频发的重要因素之一。本项目将基于动力学模型方法，考虑非生物因子对浮游植物入侵的影响，建立刻画近海浮游植物入侵的种群动力学模型。定义用以刻画入侵浮游植物繁殖能力的生态再生指标。系统分析温度、季节性气候变化、磷碳比等非生物因子对外来浮游植物入侵的影响。应用入侵阈值分析方法探究入侵浮游植物与土著浮游植物的竞争，得到外来浮游植物受非生物因子影响的入侵阈值。依据外来浮游植物的入侵阈值科学制定压载水的排放策略。本项目不仅为外来海洋生物入侵风险评估从动力学模型角度提供了新的方法，同时也为外来海洋生物入侵风险管理提供了重要依据。

非生物因子是诱发浮游植物水华的重要因素。本项目基于动力学模型方法，考虑非生物因子对浮游植物生长的影响，从不同角度建立了刻画浮游植物生长的动力学模型，定义了用以刻画浮游植物繁殖能力的生态再生指标，系统分析了温度、光照、营养盐等非生物因子对浮游植物生长的影响，比较了连续模型和离散模型的动力学行为差异。项目主要研究内容包括：1）磷碳比对浮游生物相互作用的模型研究；2）温度和光照对浮游植物生长影响的模型分析；3）环境毒素对水生生物生长影响的模型探究。基于项目支持，共发表SCI论文5篇。本项目为探究非生物因子对外来浮游生物入侵的影响奠定理论基础，为控制外来浮游生物入侵从动力学模型角度提供新思路。