Population dynamics can be influenced by physical and biological factors, particularly in stressful environments. Introduced species usually have great physiological plasticity, resulting in populations with different traits. Undaria pinnatifida, a macroalga originally described from northeast Asia, was introduced in Northern Patagonia, Argentina (San Matías Gulf) around 2010. To describe the spatio-temporal variability in population structure and morphometry of U. pinnatifida, we conducted monthly field samplings for 2 years at the intertidal area of two contrasting sites in the San Matías Gulf. Individuals of U. pinnatifida were classified by developmental stage, and their morpho-gravimetric variables were measured. In both intertidal sites juveniles were found in higher proportion during austral autumn and grew and matured during the autumn-winter months (from May onwards), and individuals senesced during early austral summer (December and January). Conversely, density and biomass were largely different between sites, and individuals showed slight morphological variability between sites. Environmental (e.g., nutrient concentration, available substrate) and biological factors (e.g., facilitation, competition) may explain the observed differences. Since there is not a macroalga with U. pinnatifida morphometrical characteristics in the intertidal environments of San Matías Gulf, studying this recent introduction gives us a better understanding of its potential ecological effects.

中文翻译：

---

相同物种，不同种群动态：阿根廷北巴塔哥尼亚潮间带裙带菜（Ochrophyta、Phaeophyceae）的时空差异

人口动态可能受到物理和生物因素的影响，特别是在压力环境中。引入的物种通常具有很大的生理可塑性，导致种群具有不同的性状。裙带菜 (Undaria pinnatifida)是一种最初来自东北亚的大型藻类，于 2010 年左右被引入阿根廷巴塔哥尼亚北部（圣马蒂亚斯湾）。为了描述裙带菜种群结构和形态测量的时空变化，我们每月对 2 个国家进行实地采样。年在圣马蒂亚斯湾两个对比地点的潮间带地区进行了研究。根据发育阶段对U. pinnatifida个体进行分类，并测量其形态重量变量。在这两个潮间带地点，幼鱼在南半球秋季的比例较高，在秋冬季（五月起）生长和成熟，个体在南半球初夏（十二月和一月）衰老。相反，不同地点之间的密度和生物量有很大差异，并且不同地点之间的个体表现出轻微的形态变异。环境（例如，营养物浓度、可用底物）和生物因素（例如，促进、竞争）可以解释观察到的差异。由于圣马蒂亚斯湾潮间带环境中不存在具有U. pinnatifida形态特征的大型藻类，研究这一新近引入的藻类可以让我们更好地了解其潜在的生态影响。