Integrating physiological threshold experiments with climate modeling to project mangrove species' range expansion.
Predictions of climate-related shifts in species ranges have largely been based on correlative models. Due to limitations of these models, there is a need for more integration of experimental approaches when studying impacts of climate change on species distributions. Here, we used controlled experiments to identify physiological thresholds that control poleward range limits of three species of mangroves found in North America. We found that all three species exhibited a threshold response to extreme cold, but freeze tolerance thresholds varied among species. From these experiments, we developed a climate metric, freeze degree days (FDD), which incorporates both the intensity and the frequency of freezes. When included in distribution models, FDD accurately predicted mangrove presence/absence. Using 28 years of satellite imagery, we linked FDD to observed changes in mangrove abundance in Florida, further exemplifying the importance of extreme cold. We then used downscaled climate projections of FDD to project that these range limits will move northward by 2.2-3.2 km yr(-1) over the next 50 years.
['Cavanaugh|Kyle C|KC|', 'Parker|John D|JD|', 'Cook-Patton|Susan C|SC|', 'Feller|Ilka C|IC|', 'Williams|A Park|AP|', 'Kellner|James R|JR|']
D000220:Adaptation, Biological D032407:Avicennia D057231:Climate Change D029764:Combretaceae D003710:Demography D005431:Florida D005615:Freezing D005843:Geography D008962:Models, Theoretical D011157:Population Dynamics D043982:Rhizophoraceae D063809:Satellite Imagery D013045:Species Specificity D053833:Wetlands
range expansion climate change freeze tolerance Avicennia germinans Laguncularia racemosa Rhizophora mangle ecological thresholds species distribution modeling