Greetings Donnie:
Well, it depends on what kind of tree seed! Some tree seed needs to be planted prior to dessication; however, some seed such as ash, maple, cherry, yellow-poplar, etc. can be "dry-stored" for extended periods (3-7 years) at proper temperature and moisture levels without affecting germination potential.
However, excessive heat and dessication will most certainly result in germination failure. For your edification, please refer to the Illinois Direct Seeding Handbook:
ftp://ftp-fc.sc.egov.usda.gov/IL/forestry/species.pdf
Best of luck!