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nph12647-sup-0001-FigS1-TableS1-S3.docxWord document46K

Fig. S1 Mean combined spring (March and April) temperatures in Massachusetts for the years 1852–2013.

Table S1 Collection dates for twigs in the 2011–2012 pilot study and the 2013 main study, together with chilling units and thermal units that had occurred up to the day of collection, and the day length

Table S2 Days to first leaf out for study species for each collection period under the natural day treatment and chilling categories for the first year pilot laboratory study

Table S3 Results of simple linear regressions measuring the response of leaf-out timing to mean March and April temperature for the field study in Concord, MA, USA