Ecological Archives E095-071-A1

Sacha M. O'Regan, Wendy J. Palen, Sean C. Anderson. 2014. Climate warming mediates negative impacts of rapid pond drying for three amphibian species. Ecology 95:845–855. http://dx.doi.org/10.1890/13-0916.1

Appendix A. Temperature data and degree-days across treatments.

Using the temperature data we logged for our pool treatments, we calculated degree-days as the number of degrees Celsius that the daily mean temperature exceeded a pre-specified developmental threshold of 10°C (Charnov and Gillooly 2003). R. aurora and P. regilla degree-days corresponding with the median proportion metamorphosed were nearly the same (range of 567.2 to 599.4 and 440.3 to 491.3 degree-days for R. aurora and P. regilla, respectively), regardless of drying treatment (Fig. A1). It appears that P. regilla has the lowest thermal time requirement for metamorphosis (440.3 to 491.3 degree-days). Warming hastened development time by allowing more rapid accumulation of degree-days. S. intermontana tended to remain in the pools longer when they were permanent, accumulating more than the minimum degree-days before metamorphosing, which suggests that these tadpoles slow development in the absence of a rapid-drying cue (range of 533 to 650 degree-days).

FigA1

Fig. A1. Temperature data logged hourly over the course of the experiment in the mesocosms and at three breeding sites where egg masses used in the experiment were collected. Mean temperatures of the treatments were also translated into cumulative degree-days. The cumulative degree-day on the date corresponding with the median proportion of tadpoles metamorphosed in each treatment is overlaid for each species (S, P, R).


 

Literature Cited

Charnov, E., and J. F. Gillooly. 2003. Thermal time: body size, food quality and the 10°C

rule. Evolutionary Ecology Research 5:43–51.


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