Biodiversity open-access databases are valuable resources in the structuring and accessibility of species occurrence data. By compiling different data sources, they reveal the uneven spatial distribution of knowledge, with areas or taxonomic groups better prospected than others. Understanding the determinants of spatial and taxonomic knowledge gaps helps in informing the use of open-access data. Here, we identified knowledge gaps' determinants within a French regional biodiversity database, in the largest administrative region in France. Knowledge gaps were assessed using two metrics, completeness and ignorance scores, for 8 taxonomic groups covering five vertebrates and three invertebrates groups. The data was analyzed for the entire region, but also at the level of the three former sub-regions, to identify the potential drivers that may account for knowledge gaps' determinants. Our findings show that invertebrates were characterized by higher knowledge gaps than vertebrates. Overall, knowledge gaps are influenced by variables related to sites' accessibility rather than ecological appeal across both metrics. All groups shared similar determinants of gaps, except for the impact of agricultural pressure which is found to be more significant for invertebrates than vertebrates. Ultimately, our study emphasizes the impact of biodiversity governance, through local funding and regional political decisions, on knowledge distribution in open-access databases. We recommend limiting these biases by redirecting biodiversity funding towards under-sampled taxonomic groups and under-prospected areas. When not possible, users of data extracted from these databases should correct for spatial-sampling biases (SSP) using knowledge gaps' maps in order to get a more accurate understanding of species occurrence.

翻译：生物多样性开放获取数据库在物种出现数据的结构化和可访问性方面是宝贵的资源。通过整合不同数据源，它们揭示了知识空间分布的不均衡性，某些地区或分类群比其他地区或分类群得到了更充分的调查。理解空间和分类知识缺口的决定因素有助于指导开放获取数据的使用。本文中，我们在法国最大的行政区域内，以一个法国区域生物多样性数据库为对象，识别了知识缺口的决定因素。知识缺口通过完整性得分和忽视度得分两个指标进行评估，涵盖八个分类群，包括五个脊椎动物群和三个无脊椎动物群。数据分析不仅针对整个区域，还基于三个历史子区域层面进行，以识别可能解释知识缺口决定因素的潜在驱动因子。我们的研究结果表明，无脊椎动物比脊椎动物表现出更高的知识缺口。总体而言，两个指标均显示，知识缺口更多受站点可访问性相关变量的影响，而非生态吸引力。除农业压力的影响对无脊椎动物比脊椎动物更为显著外，所有分类群的缺口决定因素基本相似。最终，我们的研究强调了通过地方资助和区域政治决策实施的生物多样性治理对开放获取数据库中知识分布的影响。我们建议通过将生物多样性资金重新导向采样不足的分类群和调查不充分的地区来减少这些偏差。若无法实现，从这些数据库中提取数据的使用者应利用知识缺口地图进行空间采样偏差校正，以获得更准确的物种出现理解。