Spatial patterns of species diversity in sand dune plant communities in Yucatan, Mexico: importance of invasive species for species dominance patterns

<b><i>Background</i></b>: Coastal ecosystems in Mexico remain understudied in spite of their ecological, economic and conservation value and are being impacted by human activities along the coast. Knowledge on spatial patterns of plant species distribution that helps preserve these fragile ecosystems is crucial. <b><i>Aims</i></b>: We evaluated differences in species richness, species diversity and species dominance patterns in 16 plant communities as well as the degree to which differences were driven by climatic conditions in sandy dunes in Yucatán. We evaluated the importance of invasive species in mediating patterns of species diversity and species dominance patterns. <b><i>Results</i></b>: We found wide variation in plant species richness, species diversity and species dominance patterns among communities that stems from broad climatic differences along dune systems. Invasive plants represent almost one-third of total species richness and seem to be drastically changing the species dominance patterns in these communities. <b><i>Conclusions</i></b>: Regional climatic differences along the Yucatán north coast seems to be a major driver of plant diversity and species composition. Our findings suggest that invasive plants have successfully colonised and spread along the coast over the past 30 years. Even though invasive species do not alter spatial patterns of species diversity, they are becoming more dominant with potential detrimental consequences for native plants.

**<i>背景</i>**：尽管墨西哥沿岸生态系统具备重要的生态、经济与保护价值，但相关研究仍相对不足，且正遭受沿岸人类活动的持续影响。掌握有助于保护这类脆弱生态系统的植物物种空间分布格局相关知识，具有关键意义。
**<i>研究目的</i>**：本研究针对尤卡坦半岛沙丘带内的16个植物群落，评估其物种丰富度、物种多样性及物种优势度格局的差异，并探究气候条件对这些差异的驱动程度；同时分析入侵物种在调控物种多样性与物种优势度格局中的作用。
**<i>研究结果</i>**：本研究发现，不同植物群落间的物种丰富度、物种多样性及物种优势度格局存在显著差异，这种差异源于沙丘系统沿线的广泛气候异质性。入侵植物物种数约占总物种丰富度的三分之一，且似乎正大幅改变这些群落内的物种优势度格局。
**<i>研究结论</i>**：尤卡坦北沿岸的区域气候差异，是驱动植物多样性与物种组成的主要因素。本研究结果表明，入侵植物在过去30年间已成功在沿岸区域定殖并扩散。尽管入侵物种并未改变物种多样性的空间分布格局，但其优势度正不断提升，可能对本地植物造成潜在的有害影响。