TABLE 2.

Hypotheses.

Hypothesis	Description
1	Mortality is increasing globally due to rising sea levels and freshwater levels.
2	Mortality results from the interaction of topographic, hydrologic, and physiological factors.
3	Glycophytes will experience more rapid and widespread mortality than halophytes.
4	Hydraulic failure and carbon starvation are common processes, with taxa‐specific adaptations leading to a range of mortality thresholds.
5	Hypoxia and salinity drive similar mechanisms of mortality with the exception of toxicity associated with elevated salinity.
6	Hydraulic failure is driven by hypoxia‐ and salinity‐ induced reductions in belowground water uptake.
7	Carbon starvation is driven by reduced stomatal and mesophyll conductance, lost turgor, photosynthetic ion toxicity, phloem transfer reductions, crown loss, and elevated respiration.
8	Reduced growth predisposes plants to mortality through physical and physiological feedbacks.
9	Rising CO2 can alleviate or exacerbate mortality associated with rising water levels.
10	Rising droughts and VPD will exacerbate mortality due to rising water levels.

Note: Numerous hypotheses arise from application of the hydraulic framework to predict mortality from sea‐level and freshwater‐level rise. Here we list some of the most critical hypotheses that should be tested to allow improved understanding and prediction of future coastal woody‐plant mortality. These hypotheses address the interaction between topography and physiology, the physiological mechanisms underlying hydraulic failure and carbon starvation, and the potential interactions of changing CO₂ and climate with the physiological responses to rising inundation.