Winter cold and micro-refugia

Last Saturday night (2/10) as Honolulu suffered with temperatures dropping to 64F (the Hawaiian “coolmageddon”), a few miles away temperatures at the ridge directly above me dropped to below 50F.

However, for those concerned about me and the bitter Hawaiian cold, don’t be as I am protected in the gulch below from the worst of it. Based on the data collected so far, temperatures vary widely between where I am and on the exposed ridge just a few feet away. During the day, soil temperatures on the ridge may be more than 8F warmer than here; and during the night as much as 3F colder up there.

Scientists think that this large local variation in climate allows some species to persist in so called ‘micro-refugia’ as the climate changes. Past research suggests that small pockets of forests (i.e., micro-refugia) allowed the northern hemisphere to be rapidly reforested as glaciers retreated at the end of the last ice age. Detailed forest environmental data collected here and elsewhere may clarify the importance of micro-refugia in helping Hawaiian plants persist in a rapidly changing climate.