Mangiante Michael J, Davis Amy J S, Panlasigui Stephanie, Neilson Matthew E, Pfingsten Ian, Fuller Pam L, Darling John A
Oak Ridge Institute of Science and Education (ORISE), U.S. Environmental Protection Agency, National Exposure Research Laboratory, Research Triangle Park, NC 27711, USA.
U.S. Geological Survey, Wetland and Aquatic Research Center, Gainesville, FL 32653, USA.
Aquat Invasions. 2018 Sep 1;13(3):323-338. doi: 10.3391/ai.2018.13.3.02.
Understanding the spatial and temporal dynamics underlying the introduction and spread of nonindigenous aquatic species (NAS) can provide important insights into the historical drivers of biological invasions and aid in forecasting future patterns of nonindigenous species arrival and spread. Increasingly, public databases of species observation records are being used to quantify changes in NAS distributions across space and time, and are becoming an important resource for researchers, managers, and policy-makers. Here we use publicly available data to describe trends in NAS introduction and spread across the conterminous United States over more than two centuries of observation records. Available data on first records of NAS reveal significant shifts in dominance of particular introduction patterns over time, both in terms of recipient regions and likely sources. These spatiotemporal trends at the continental scale may be subject to biases associated with regional variation in sampling effort, reporting, and data curation. We therefore also examined two additional metrics, the number of individual records and the spatial coverage of those records, which are likely to be more closely associated with sampling effort. Our results suggest that broad-scale patterns may mask considerable variation across regions, time periods, and even entities contributing to NAS sampling. In some cases, observed temporal shifts in species discovery may be influenced by dramatic fluctuations in the number and spatial extent of individual observations, reflecting the possibility that shifts in sampling effort may obscure underlying rates of NAS introduction.
了解非本土水生物种（NAS）引入和扩散背后的时空动态，有助于深入洞察生物入侵的历史驱动因素，并辅助预测非本土物种未来的到达和扩散模式。物种观测记录的公共数据库越来越多地被用于量化NAS在空间和时间上分布的变化，正成为研究人员、管理人员和政策制定者的重要资源。在此，我们利用公开数据，通过两个多世纪的观测记录来描述NAS在美国本土引入和扩散的趋势。NAS首次记录的现有数据显示，特定引入模式的主导地位随时间推移发生了显著变化，无论是在接收区域还是可能的来源方面。大陆尺度上的这些时空趋势可能会受到与采样工作、报告和数据管理中的区域差异相关的偏差影响。因此，我们还研究了另外两个指标，即个体记录的数量和这些记录的空间覆盖范围，它们可能与采样工作联系更为紧密。我们的结果表明，大规模模式可能掩盖了不同区域、时间段甚至为NAS采样做出贡献的实体之间的显著差异。在某些情况下，观察到的物种发现的时间变化可能受到个体观测数量和空间范围剧烈波动的影响，这反映出采样工作的变化可能会掩盖NAS引入的潜在速率。
