气候变化领域集成服务门户

We developed a spatially-explicit, habitat suitability model that can be used to identify and predict areas at higher risk for non-native dwarf eelgrass (Zostera japonica) invasion. The niche-based model uses simple readily available environmental parameters (depth, near shore slope, and salinity) to quantitatively describe habitat suitable for Z. japonica invasion based on ecology and physiology from the primary literature. Habitat suitability is defined with values ranging from zero to one, where one denotes areas most conducive to Z. japonica and zero denotes areas not likely to support Z. japonica growth. Functional forms and equations for the ZJHSM were developed a priori, and the model was validated by comparison with multiple years of independent field-collected spatial Z. japonica maps from Yaquina Bay, Oregon, USA, an area that has well documented Z. japonica expansion over the last two decades. Sensitivity analysis performed to evaluate the contribution of each parameter to the model prediction revealed that depth was the most important factor. The highest suitability values for Z. japonica occurred in the mid to upper portions of the intertidal zone, with larger expanses occurring in the lower estuary. While the upper estuary did contain suitable habitat, most areas were not as large as in the lower estuary, due to inappropriate depth, a steeply sloping intertidal zone, and lower salinity. The lowest suitability values occurred below the lower intertidal zone, within the Yaquina River channel. Shallow sloping intertidal soft-bottom sediments appear to provide optimum habitat for this species. This model would allow resource managers to identify those areas at risk for future invasion, and develop proactive plans for limiting the opportunities for further introduction and spread in areas where it does not currently occur.