Ottermanns Richard, Szonn Kerstin, Preuβ Thomas G, Roβ-Nickoll Martina
Institute for Environmental Research, RWTH Aachen University, Aachen, Germany.
PLoS One. 2014 May 8;9(5):e96270. doi: 10.1371/journal.pone.0096270. eCollection 2014.
In this study we present evidence that anthropogenic stressors can reduce the resilience of age-structured populations. Enhancement of disturbance in a model-based Daphnia population lead to a repression of chaotic population dynamics at the same time increasing the degree of synchrony between the population's age classes. Based on the theory of chaos-mediated survival an increased risk of extinction was revealed for this population exposed to high concentrations of a chemical stressor. The Lyapunov coefficient was supposed to be a useful indicator to detect disturbance thresholds leading to alterations in population dynamics. One possible explanation could be a discrete change in attractor orientation due to external disturbance. The statistical analysis of Lyapunov coefficient distribution is proposed as a methodology to test for significant non-linear effects of general disturbance on populations. Although many new questions arose, this study forms a theoretical basis for a dynamical definition of population recovery.
在本研究中，我们提供了证据表明人为压力源会降低年龄结构种群的恢复力。在基于模型的水蚤种群中增强干扰会导致混沌种群动态受到抑制，同时增加种群年龄组之间的同步程度。基于混沌介导生存理论，揭示了暴露于高浓度化学压力源下的该种群灭绝风险增加。李雅普诺夫系数被认为是检测导致种群动态变化的干扰阈值的有用指标。一种可能的解释是由于外部干扰导致吸引子方向发生离散变化。提出对李雅普诺夫系数分布进行统计分析作为一种方法，以检验一般干扰对种群的显著非线性影响。尽管出现了许多新问题，但本研究为种群恢复的动态定义奠定了理论基础。
