The introduction of non-indigenous species (NIS) in new environments represents a major threat for coastal ecosystems. A good understanding of the mechanisms and magnitude of the impact of NIS colonisation on native ecosystems is becoming increasingly crucial to develop mitigation measures and prevent new invasions. In this present study, we asked if distinct coastal benthic communities from an oceanic island can have different vulnerability to NIS colonisation process. First, PVC settlement plates were deployed for 1 year on the rocky shore of two different locations of Madeira Island (North versus South coast). Then, we implemented a mesocosm experiment where recruited plate communities were maintained under different levels of NIS propagule pressure in order to assess their vulnerability to NIS colonisation process. Results showed that NIS colonisation success was not influenced by the level of propagule pressure, but however, final colonisation patterns varied depending on the origin of the communities. This variability can be attributed to major structural differences between the preponderant species of each community and therefore to the biotic substrate they offer to colonisers. This study highlights how biotic features can alter the NIS colonisation process and importantly, shows that in an urbanisation context, the nature of the resident communities facing invasions risks needs to be closely assessed.

中文翻译：

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海洋岛屿底栖生物群落中非土著物种定居的变异性

在新环境中引入非土著物种（NIS）对沿海生态系统构成了重大威胁。对NIS殖民化对本地生态系统影响的机制和程度的深入了解对于制定缓解措施和防止新的入侵变得越来越重要。在本研究中，我们询问来自海洋岛屿的不同沿海底栖生物群落是否对NIS殖民化过程具有不同的脆弱性。首先，在马德拉岛两个不同地点（北海岸和南海岸）的岩石海岸上部署PVC沉降板一年。然后，我们进行了一个介观试验，其中将招募的板块群落维持在不同水平的NIS繁殖压力下，以评估其对NIS定植过程的脆弱性。结果表明，NIS的定殖成功率不受繁殖压力的影响，但是最终定殖的方式因群落的起源而异。这种可变性可以归因于每个社区的优势物种之间的主要结构差异，因此归因于它们提供给定居者的生物底物。这项研究突出了生物特征如何改变NIS的定殖过程，并且重要地表明，在城市化的背景下，需要仔细评估面临入侵风险的居民社区的性质。这种可变性可以归因于每个社区的优势物种之间的主要结构差异，因此归因于它们提供给定居者的生物底物。这项研究突出了生物特征如何改变NIS的定殖过程，并且重要地表明，在城市化的背景下，需要仔细评估面临入侵风险的居民社区的性质。这种可变性可以归因于每个社区的优势物种之间的主要结构差异，因此归因于它们提供给定居者的生物底物。这项研究突出了生物特征如何改变NIS的定殖过程，并且重要地表明，在城市化的背景下，需要仔细评估面临入侵风险的居民社区的性质。