SACRAMENTO, Calif. — There’s nothing better than seeing a new tree being planted if you’re Justin Rubio, who is a volunteer coordinator with the Sacramento Tree Foundation, and a self-confessed tree lover.

“A tree-hugger, yes. It is what I spend all my time doing,” Rubio said.

The organization offers free trees to anyone in the state’s capital.

A volunteer planting event at John H. Still Middle School in February, a prime example Rubio said of the organization’s efforts to help create a tree canopy where it’s lacking. Rubio said though no matter the tree situation in any area, there’s always a need for more.

“You don’t know when some of these trees are going to come down due to age. You don’t know when we’re going to get another storm like we had that’s going to toss down a bunch of trees,” he said.

The Sacramento urban forest can certainly use more than one leg up to keep its tree canopy healthy. A new study by UC Davis assistant professor Emily Meineke shows trees in urban areas are under pressure thanks to vehicle pollution.

“Trees from highly polluted areas, for some reason, the leaves are more attractive to herbivores and seem to be more nutritious. So caterpillars seem to like to eat trees in more heavily polluted areas,” Meineke said.

Meineke said they are yet to discover what exactly makes them more attractive but believes it may have something to do with the tree’s defenses being lowered by pollution. 

“There seems to be just this attraction to polluted leaves that I never expected to see in these caterpillars. I think it’s an exciting new area of research that shocked me,” she said.

Making sure hardy trees are planted in Sacramento is something the Sacramento Tree Foundation’s executive director Jessica Sanders said they are always looking to do, but remarked the best suited trees are not always an option.

“There’s a lot of trees, especially as we are looking toward more resilient species for the future, that just aren’t grown commercially, or maybe grown in limited quantities in the industry trade,” Sanders said.

Even with constraints on certain tree species, thankfully for the foundation, Rubio said there is no shortage of volunteers, especially young people, who want to plant trees.

 “For them to come out and see that they actually can make a difference. That’s the big part,” he said.

An encouraging prospect, Rubio said of more future tree-huggers, and the possibility of a continued healthy tree canopy even with continued pollution.