鸭绿江口及邻近海域生物群落的胁迫响应

利用ABC曲线法结合粒径谱理论对鸭绿江口近岸海域的生物群落特征、优势种演替、多样性水平、稳定性状况等进行了分析,并尝试构建了鸭绿江口近岸海域生物群落稳定性的评估模型.研究结果表明,鸭绿江口滨海湿地生物群落结构相对简单,优势种演替明显,受外界干扰较大.春、夏季浮游植物以r-对策者为主,群落数量偏离平衡点；秋季以r-对策者为主的微小型浮游植物逐渐被中大型k-对策者演替,群落完成反馈调节,恢复到平衡点.浮游动物由于较高的能量供应其幼体全年一直处于较高优势水平,但生态效率转换相对较慢.潮间带底栖生物群落结构相对简单,优势种演替明显,系统具有低多样性低密度的特点,群落在夏季受外界扰动较大.游泳生物群落主要以小型个体为主,已处于极不稳定状态.构建的群落稳定性评估模型测算结果与上述结论基本一致,这也验证了该评估模型具有一定的有效性与实用性.综合以上分析结果,说明鸭绿江口近岸海域生物群落稳定性较差,受外界干扰比较严重.

The stress response of biological communities in China's Yalu River Estuary and neighboring waters

This paper analyzes the features of the biological community, succession of dominant species, diversity, and stability of the Yalu River Estuary offshore waters using an ABC curve method combined with particle-size spectrum theory, and establishes a model to evaluate the stability of the Yalu River Estuary ecosystem area. The aim is to understand the ecological health and status of the Yalu River Estuary wetland reserve nature reserve and to analyze problems related to this ecosystem. The results show the structure of the Estuary's biological community is relatively simple; the patterns of succession are obvious for the dominant species and this ecosystem is susceptible to outside interference. Sufficient sunlight, appropriate temperatures and the accumulation of nutrients provide favorable conditions for phytoplankton growth in spring, so microorganisms based on R-countermeasures multiply rapidly (Skeletonema costatum, Asterionella kariana), causing the community to deviate from the point of equilibrium. Rivers constantly supply nutrients from land-based sources in the summer, so the dominant species are replaced by Nitzschia delicatissima. In fall, more nutrients are consumed than are replaced by the river, so the micro bio-based R-countermeasures will be gradually replaced by k-countermeasures (Coscinodiscus spp., Fragilaria spp., Ceratium fusus), the community completes its cycle of natural feedback-driven regulation and returns to equilibrium. Similarly, the supply of high energy phytoplankton leads to zooplankton blooms; small herbivorous copepod (section) larvae have been present in high numbers throughout the year. Based on the ABC curve results and standard biomass spectrum analysis, external disturbances impact the benthic community in summer because migratory waders feed on benthos. At the peak of migration waders have a more significant influence on intertidal food organisms. After migration peaks, the benthic food biomass recovers gradually, and the community gradually tends to stabilize to former population levels. Standard biomass spectrum analysis confirms the nekton community is comprised primarily of small numbers of individuals, and a stability assessment also shows the nekton community is in a serious state of imbalance. The characteristics of the ABC curve show the Yalu River Estuary biological community has three different seasons, but according to W statistics, phytoplankton and zooplankton communities in the spring and summer are affected significantly by external disturbances; this phenomenon is also observed in the intertidal benthic community in the summer, while the nekton community is always in an unstable state. The characteristics of the standard biomass spectrum slope, the residual variance of spectral lines and correlation coefficient of the regression line also confirm these results. The estimation results of the model evaluating community stability in this paper are basically in accord with the above conclusions, indicating the evaluation model is effective and practical. Above all, it indicates the biological community of the Yalu River Estuary has poor stability, and is seriously impacted by external pressures. Inorganic nitrogen and inorganic phosphorus, which come from terrestrial input and marine aquaculture, are the main environmental factors affecting the biological community stability in the offshore wetlands of the Yalu River Estuary.