Vidal E, Médail F, Tatoni T, Bonnet V
Institut Méditerranéen d'Ecologie et de Paléocologie (CNRS), case 461, Université d'Aix-Marseille III, Faculté des Sciences et Techniques de Saint-Jérôme, F-13397 Marseille cedex 20, France e-mail:
Oecologia. 2000 Feb;122(3):427-434. doi: 10.1007/s004420050049.
The analysis of long-term floristic changes was conducted on nine west-Mediterranean limestone islands (size range: 2-95 ha) which have recently undergone a severe demographic explosion in their yellow-legged gull Larus cachinnans colonies. A comparison of past and present plant inventories was used to quantify extinction-colonization events, both from a classical biogeographical perspective (per island approach) and a metapopulational perspective (per species approach). In the first approach, floristic turnover intensity was negatively related to island area and positively to gull nesting density, but was independent of island isolation. In the second, species turnover rate was compared with a set of plant species life history traits (dispersal mode, Grime CSR strategy, growth form, biogeographical type). Plants which exhibited the highest turnover rate were primarily ruderal, annual, wind-dispersed species with a wide geographic range. The severe disturbance induced by seabird activities has tended to select and favour some adapted plant species groups at the expense of indigenous island taxa. The relationships between specific turnover intensity and plant life history traits justify using the metapopulation approach and point to the importance of interspecific variations in extinction-colonization patterns.
对西地中海的九个石灰岩岛屿（面积范围：2 - 95公顷）进行了长期植物区系变化分析，这些岛屿上黄腿鸥（Larus cachinnans）的繁殖地最近经历了严重的数量激增。通过比较过去和现在的植物清单，从经典生物地理学角度（每个岛屿的方法）和集合种群角度（每个物种的方法）对灭绝 - 定殖事件进行量化。在第一种方法中，植物区系更替强度与岛屿面积呈负相关，与海鸥筑巢密度呈正相关，但与岛屿隔离程度无关。在第二种方法中，将物种周转率与一组植物物种生活史特征（传播方式、Grime CSR策略、生长形式、生物地理类型）进行比较。周转率最高的植物主要是杂草性、一年生、风媒传播且地理分布范围广的物种。海鸟活动引起的严重干扰倾向于选择并有利于一些适应性强的植物物种组，而牺牲了岛屿本土分类群。特定周转率强度与植物生活史特征之间的关系证明了使用集合种群方法的合理性，并指出了灭绝 - 定殖模式中种间差异的重要性。
