Today’s Arbor Day! Time to hug the trees in your life and thank them. In addition to providing pretty views, soothing shade, and climbing opportunities, trees save our lives and planet.

According to a study focusing on the health benefits of trees conducted by the U.S. Forest Service and the Davey Institute, urban forests save thousands of lives every year and improve many more.

“Trees act as giant filters that clean the air we breathe,” says R.J. Laverne, a board-certified master arborist at The Davey Tree Expert Company. “They intercept airborne particles, cooling the air, and they absorb pollutants such as carbon monoxide, sulfur dioxide, and nitrogen dioxide, changing those pollutants into less harmful forms.”

The truth is, we couldn’t exist as we do if there were no trees, says Laverne. “A mature leafy tree produces as much oxygen in a season as 10 people inhale in a year.”

Trees improve overall quality of life, making people happier. They also cut down on hospital visits and days taken off work, and they’ve even been shown to reduce levels of domestic violence and foster more sociable, safer neighborhoods, says Laverne, who has studied the emotional benefits of trees.

“Places with nature and trees may provide settings in which relationships grow stronger and violence is reduced,” he says. “Trees bring people together. Data shows that neighborhoods with shady streets and parks create outdoor spaces that attract people. When people are drawn to spaces with trees, they are more likely to interact with their neighbors and become friends.”

Trees are just as good for the environment—performing incredible services that help ensure the health of our planet. They intercept and conserve rainwater so that it percolates into the ground rather than running off into local waterways. Trees also filter sewage and farm chemicals, reduce the effects of animal wastes, and clean roadside spills. And they help control erosion by binding the soil.

If those aren’t enough reasons to love your trees, consider your wallet. Trees save you a lot of money—and can even make you a lot of money. Houses with established trees earn homeowners on average three to seven percent more on home sales, and the reduction in energy bills from landscape trees is substantial. Homes without surrounding trees can become heat islands.

So go ahead and hug your trees. They deserve it.

Julie Bawden-Davis is a garden writer and master gardener, who since 1985 has written for publications such as Organic Gardening, Wildflower, Better Homes and Gardens and The Los Angeles Times. She is the author of seven books, including Fairy Gardening, The Strawberry Story Series, and Indoor Gardening the Organic Way, and is the founder of HealthyHouseplants.com.