Supplement 1. Site means (mean number of acorns counted per 30 seconds) and environmental data (from the PRISM database) used in the analyses (1994–2011).

File List Acorn_data.txt (md5: 7c7db30d39b36313243ab0042b902d11) Description Acorn_data.txt is a tab-delimited ASCII file. The file contains data for mean acorn production (measured as mean number of acorns counted per 30 sec) for Q. lobata and Q. douglasii for 12 California sites surveyed between 1994 and 2011 and weather data as estimated from the PRISM database. Column definitions: 1 = Site name 2 = Latitude (decimal degrees) 3 = Longitude (decimal degrees) 4 = Year 5 = Species 6 = Mean log-transformed count (acorns per 30 sec) 7 = Mean maximum April temperature 8 = Mean maximum March temperature 9 = March rainfall 10 = April rainfall 11 = March rainfall the prior year (year x - 1) 12 = April rainfall the prior year (year x - 1) 13 = Mean maximum summer temperature (May through August) 14 = Mean maximum summer temperature the prior year (year x - 1) 15 = Winter rainfall (Nov. of year x - 1 through Feb. of year x) 16 = Winter rainfall the prior year (Nov. of year x - 2 through Feb. of year x - 1) 17 = Mean minimum winter temperature 18 = Mean maximum autumn temperature (Sept. through Nov. of year x - 1) 19 = Mean maximum March temperature the prior year (year x - 1) 20 = Mean maximum April temperature the prior year (year x - 1) 21 = 'Combined environmental variable' for Q. lobata (see text) 22 = 'Combined environmental variable' for Q. douglasii (see text)