Across the country, food banks and homeless shelters have seen a staggering drop in donations. Giving to the Salvation Army is down 22 percent this year in Massachusetts alone. And these charitable declines are coupled with the fact that this time of year is crucial for the nonprofit sector’s bottom line. According to a recent Charity Navigator survey, charities nationwide receive approximately 41 percent of their annual contributions between Thanksgiving and New Year’s. Yet, 59 percent of nonprofits are reporting that their donation income is flat or lower this year than in 2010.