Romero-Alvarez Daniel, Escobar Luis E, Varela Sara, Larkin Daniel J, Phelps Nicholas B D
Hospital General Enrique Garcés, Unidad de Epidemiología, Quito, Ecuador.
Minnesota Aquatic Invasive Species Research Center, Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota, St. Paul, MN, United States of America.
PLoS One. 2017 Jul 13;12(7):e0180930. doi: 10.1371/journal.pone.0180930. eCollection 2017.
Starry stonewort (Nitellopsis obtusa) is an alga that has emerged as an aquatic invasive species of concern in the United States. Where established, starry stonewort can interfere with recreational uses of water bodies and potentially have ecological impacts. Incipient invasion of starry stonewort in Minnesota provides an opportunity to predict future expansion in order to target early detection and strategic management. We used ecological niche models to identify suitable areas for starry stonewort in Minnesota based on global occurrence records and present-day and future climate conditions. We assessed sensitivity of forecasts to different parameters, using four emission scenarios (i.e., RCP 2.6, RCP 4.5, RCP 6, and RCP 8.5) from five future climate models (i.e., CCSM, GISS, IPSL, MIROC, and MRI). From our niche model analyses, we found that (i) occurrences from the entire range, instead of occurrences restricted to the invaded range, provide more informed models; (ii) default settings in Maxent did not provide the best model; (iii) the model calibration area and its background samples impact model performance; (iv) model projections to future climate conditions should be restricted to analogous environments; and (v) forecasts in future climate conditions should include different future climate models and model calibration areas to better capture uncertainty in forecasts. Under present climate, the most suitable areas for starry stonewort are predicted to be found in central and southeastern Minnesota. In the future, suitable areas for starry stonewort are predicted to shift in geographic range under some future climate models and to shrink under others, with most permutations indicating a net decrease of the species' suitable range. Our suitability maps can serve to design short-term plans for surveillance and education, while future climate models suggest a plausible reduction of starry stonewort spread in the long-term if the trends in climate warming remain.
亮叶刚毛藻（钝节拟丽藻）是一种藻类，已成为美国备受关注的水生入侵物种。在其已定居的地方，亮叶刚毛藻会干扰水体的娱乐用途，并可能产生生态影响。明尼苏达州亮叶刚毛藻的初期入侵提供了一个预测未来扩张的机会，以便进行早期检测和战略管理。我们使用生态位模型，根据全球分布记录以及当前和未来的气候条件，确定明尼苏达州亮叶刚毛藻的适宜区域。我们使用来自五个未来气候模型（即CCSM、GISS、IPSL、MIROC和MRI）的四种排放情景（即RCP 2.6、RCP 4.5、RCP 6和RCP 8.5）评估了预测对不同参数的敏感性。从我们的生态位模型分析中，我们发现：（i）来自整个分布范围的出现情况，而不是仅限于入侵范围内的出现情况，能提供更有参考价值的模型；（ii）Maxent中的默认设置并未提供最佳模型；（iii）模型校准区域及其背景样本会影响模型性能；（iv）对未来气候条件的模型预测应限于类似环境；（v）对未来气候条件的预测应包括不同的未来气候模型和模型校准区域，以更好地捕捉预测中的不确定性。在当前气候条件下，预计明尼苏达州中部和东南部是亮叶刚毛藻最适宜的区域。未来，在一些未来气候模型下，亮叶刚毛藻的适宜区域预计会在地理范围上发生转移，而在其他模型下则会缩小，大多数情况表明该物种适宜范围将净减少。我们的适宜性地图可用于设计短期监测和教育计划，而未来气候模型表明，如果气候变暖趋势持续，从长远来看亮叶刚毛藻的扩散可能会合理减少。
