The Effects of Temperature and Nutrient Salts on the Life History of <i>Moina </i><i>micrura</i>

在全球气候变化和水体富营养化日益加剧的背景下，温度升高与氮营养盐浓度变化已成为影响水生生态系统结构和功能的关键环境因子。作为水生生态系统的关键消费者，浮游动物的生活史特征对环境变化的响应机制是理解生态系统能量流动和物质循环的重要基础。本论文选取微型裸腹溞(Moina micrura)为实验对象开展室内试验，设置不同氮营养盐浓度梯度(0.112, 0.224, 1.12, 2.24, 11.2 mg/L)，探究了不同氮营养盐条件下浮游动物对小球藻的摄食关系；随后基于摄食关系实验选取0.224 mg/L和2.24 mg/L两个氮营养盐浓度及25℃和30℃两个温度梯度进行实验。通过对微型裸腹溞生活史进行研究，结果表明，在25℃~30℃范围内，温度升高显著加快微型裸腹溞的代谢速度，使其内禀增长率和净生殖率提升，繁殖时间与世代周期缩短，种群增长加快；而氮浓度升高能提高种群生物量，促进初期增殖，且使后代个体更大。研究揭示了温度与氮营养盐相互作用对微型裸腹溞生活史的复杂影响机制，即温度主要通过加速代谢过程影响繁殖效率，氮营养盐则从直接参与生理代谢和间接优化食物质量两方面发挥作用。In the face of intensifying global climate change and increasing aquatic eutrophication, elevated temperatures and altered nitrogen nutrient salt concentrations have become pivotal environmental factors affecting the structure and functioning of aquatic ecosystems. As keystone consumers in aquatic ecosystems, the response mechanism of zooplankton’s life history traits to environmental changes is an important basis for understanding the energy transfer and material cycling of ecosystems. This study selected Moina micrura as an experimental subject to conduct indoor experiments and set up different nitrogen nutrient salt concentration gradients (0.112, 0.224, 1.12, 2.24, and 11.2 mg/L) to study zooplankton-algal feeding relations under the conditions of different nitrogen nutrient salts. Then, it selected two nitrogen nutrient salt concentrations of 0.224 mg/L and 2.24 mg/L and two temperature gradients of 25˚C and 30˚C for further experiments based on the feeding relationship experiment. Through the study of the life history of Moina micrura, the results showed that at 25˚C~30˚C, higher temperatures sped up the metabolism of Moina micrura, increasing its intrinsic growth and net reproductive rates and shortening reproduction time and generation length, thus accelerating population growth. Higher nitrogen nutrient salt concentrations also increased the population biomass, enhanced initial reproduction, and produced larger offspring. The study revealed the complex interplay of temperature and nitrogen nutrient salt on the life history of Moina micrura. Temperature mainly affected reproduction efficiency by raising metabolic rates, while nitrogen nutrient salts influenced physiological metabolism directly and food quality optimization indirectly.