Linares Cristina, Doak Daniel F, Coma Rafel, Díaz David, Zabala Mikel
Centre d'Estudis Avançats de Blanes, Accés Cala Sant Francesc 14, 17300 Blanes, Girona, Spain.
Ecology. 2007 Apr;88(4):918-28. doi: 10.1890/05-1931.
The red gorgonian Paramuricea clavata is a long-lived, slow-growing sessile invertebrate of ecological and conservation importance in the northwestern Mediterranean Sea. We develop a series of size-based matrix models for two Paramuricea clavata populations. These models were used to estimate basic life history traits for this species and to evaluate the viability of the red gorgonian populations we studied. As for many other slow-growing species, sensitivity and elasticity analysis demonstrate that gorgonian population growth is far more sensitive to changes in survival rates than to growth, shrinkage, or reproductive rates. The slow growth and low mortality of red gorgonians results in low damping ratios, indicating slow convergence to stable size structures (at least 50 years). The stable distributions predicted by the model did not differ from the observed ones. However, our simulations point out the fragility of this species, showing both populations in decline and high risk of extinction over moderate time horizons. These declines appear to be related to a recent increase in anthropogenic disturbances. Relative to their life span, the values of recruitment elasticity for Paramuricea clavata are lower than those reported for other marine organisms but are similar to those reported for some long-lived plants. These values and the delayed age of sexual maturity, in combination with the longevity of the species, show a clear fecundity/mortality trade-off. Full demographic studies of sessile marine species are quite scarce but can provide insight into population dynamics and life history patterns for these difficult and under-studied species. While our work shows clear results for the red gorgonian, the variability in some of our estimates suggest that future work should include data collection over longer temporal and spatial scales to better understand the long-term effects of natural and anthropogenic disturbances on red gorgonian populations.
红色柳珊瑚（Paramuricea clavata）是一种寿命长、生长缓慢的固着无脊椎动物，在地中海西北部具有重要的生态和保护意义。我们为两个红色柳珊瑚种群开发了一系列基于大小的矩阵模型。这些模型用于估计该物种的基本生活史特征，并评估我们所研究的红色柳珊瑚种群的生存能力。与许多其他生长缓慢的物种一样，敏感性和弹性分析表明，柳珊瑚种群增长对存活率变化的敏感度远高于对生长、收缩或繁殖率变化的敏感度。红色柳珊瑚生长缓慢且死亡率低，导致阻尼比低，这表明向稳定大小结构的收敛缓慢（至少50年）。模型预测的稳定分布与观察到的分布没有差异。然而，我们的模拟指出了该物种的脆弱性，表明两个种群都在衰退，并且在中等时间尺度上有很高灭绝风险。这些衰退似乎与近期人为干扰增加有关。相对于它们的寿命，红色柳珊瑚的补充弹性值低于其他海洋生物的报道值，但与一些长寿植物的报道值相似。这些值以及性成熟的延迟年龄，再加上该物种的长寿，显示出明显的繁殖力/死亡率权衡。对固着海洋物种进行全面的种群统计学研究相当稀少，但可以为这些难以研究且研究不足的物种的种群动态和生活史模式提供见解。虽然我们的工作对红色柳珊瑚得出了明确结果，但我们一些估计值的变异性表明，未来的工作应包括在更长的时间和空间尺度上收集数据，以更好地了解自然和人为干扰对红色柳珊瑚种群的长期影响。
