NEW HAVEN, Conn. (WTNH) – This week is National Invasive Species Awareness Week. All over the world, plants and animals are hurting the environment because they are not where they are supposed to be.

Every Tuesday morning, volunteers work on improving the green space that is New Haven’s Edgewood Park. Sometimes that means making it…a little less green.

“So this is bittersweet right here, and you can see how it twists and climbs,” said Chris Ozyck, pointing to a slender vine curling around an apple tree.

Ozyck is with the Yale School for the Environment and is the associate director of URI, the Urban Resources Initiative. An expert like him can see the park is full of invasive species, from knotweed choking the riverbank, to vines that climb up indigenous trees and starve them.

“You know, the leaves of the invasive doesn’t allow the leaves of the tree to actually get sunlight to do photosynthesis and be able to do the things that trees want to do.”

Left alone, some of those vines can get as big as trees themselves.

“We have a lot of invasive species in here and I thought it would be safer, more people would use it, if in fact we took those down and created some nice walking paths,” said volunteer Frank Cochran.

Cochran is usually focused on the vines and small weeds, but a few weeks ago, he stumbled on something that really did not look like it belonged in Edgewood Park, and he thought he had found something big. Really big.

“So I looked at it, and it’s got red bark. We don’t have any native trees with bark that looks like that that I know of,” Cochran said. “So then I went on up, all the way up and I said wait a minute, that’s about 80 feet tall. Is that a redwood tree?”

“Frank wasn’t far off,” Ozyck said. “They’re in the same family. They’re all cyprus.”

So not a redwood, but an ornamental cyprus probably planted around 1910. While it’s not native, it’s not hurting anything. The volunteers do try to promote native plants, though.

“I think the insects and the birds and all the mammals that are used to the native species do better when the native species are here,” said volunteer Stephanie FitzGerald. “They have more food.”

Those vines cause another problem, too.

“And anybody can drive along the highway of Connecticut just see large tangles of masses of vines,” said Ozyck. “They are slowly taking down the forest.”

Forests that absorb carbon and help combat global warming. Some talk about planting trees to stop climate change.

“Planting trees is great, but saving the existing trees that store carbon right now, is even better,” said Ozyck.

Encouraging the right plants to grow is what these volunteers do every week, not just invasive species week. It’s not just Edgewood Park where this is happening, either. For a list of other URI locations, click here.