Santa’s sack of toys could be a little lighter this Christmas for many of America’s neediest families who depend on the Salvation Army for everything from basic clothing and toys to holiday meals.

Salvation Army USA officials told FOXNews.com that overall Christmas donations could be down as much as 11 percent.

Compounding the dip in donations is a shortage of volunteer bell-ringers who staff Salvation Army storefront kettles.

“The fewer people we have, the fewer kettles we can put out, the less money we can bring in, the fewer people we can help," Melissa Temme of the Salvation Army USA said. "It’s a domino effect, and it’s definitely in effect this year.”

Temme guesses one reason for the shortfall is the amount of shopping now done online, which is why the Salvation Army has set up “online red kettles” to accept donations.

Wal-Mart, a major Salvation Army contributor, said online-kettle donations are up 253 percent over last year.

Major Harvey Johnson of the Salvation Army Peninsula Command in Hampton, Va., said he’s “very concerned” about the donation shortfall, which he estimated at about 30 percent from last year.

"If we can crack $250,000 this year, we’ll be happy,” Johnson said.

The shortfall could affect how well the organization serves up relief services to the general public this the winter, Johnson said.

The Salvation Army isn't the only charitable organization feeling like it's getting Scrooged.

"This year, for some reason, we're short of toys,” said Lynnette Round of the Orange County Fire Authority. “We have organizations that have requested over 365,000 toys and we're as short as 132,000, so about two-thirds."

Round is at a loss to explain why the toy shortage.

"Last year we had Hurricane Katrina and there were some disasters, so we thought that maybe people were being very generous giving to other needs and the toy drive came around and we were short,” she said. “This year we haven't encountered any disasters and we can't explain why we're having a shortage."

The United Way, the nation’s charity giant, said it isn't seeing a dip in donations as much as a change in where the money is coming from.

“A lot of contributions have come historically from workplace giving – money from paychecks," said United Way spokeswoman Sheila Consaul. “Even though our workplace giving is not as robust as it has been in the past, our major giving — people who give us $1000 or more, people who leave us in their wills — that’s up.”

Marine Corps volunteer Corp. Kevin Arnold of "Toys-for-Tots" said any decline in Christmas donations to his organization will have a profound impact.

"It means a gift on Christmas,” Arnold said. “I've actually seen some of the children receive the toys and you see their faces light up and they're just happy to get that one toy."

FOX News' Anita Vogel contributed to this report