Fourteen mature pepper and eucalyptus trees were reduced to stumps to clear the way for new banners promoting animal adoptions.
Animal activist-attorney Steven Jay Bernheim paid to have the trees cut and is helping fund the massive banners, which will be hung from the top of the building.
He said he's willing to do whatever it takes to make sure the banners are seen in order to get more people in the door to adopt.
"If we have to sacrifice a few trees - and I know we're going to plant a million in the city - in order to save thousands and thousands of dogs and cats, it's a good trade off," Bernheim said.
Brenda Barnette, the general manager of the Los Angeles Department of Animal Services, said she knew about the plan for the banners, but said the trees were to be only trimmed.
"It was a volunteer effort that meant that's what they wanted to do, was help us," she said. "We're all disappointed. Nobody would have cut the trees down on purpose."
The pepper trees, which circled the building and lined the front entrance, provided lots of shade and were a key part of the energy-efficient, $23 million building that opened three years ago.
"This was actually vandalism. This was not an effort to help," said Phyllis Daugherty, founder of Animal Issues Movement. "This is an attorney who should have been in control and should be totally liable."