'Tis the season for giving, but it's been a down year in donations for many charities.
A research study shows, some large charities have seen a rise in contributions.
But donations of food, cash and other materials are flat or went down for most nonprofits in 2011.
Food pantries and shelters cut back their services because of more need and a drop in donations.
The nonprofit Research Collaborative conducted the study among charities nationwide.
