This week's question comes from Holly Irving in Lake Echo Nova Scotia. She asks: Which trees of the same age or size provide us with the most oxygen over the course of a year, deciduous or evergreen?

Trees are more than just part of the landscape - they are life-support systems for the planet. From giving us oxygen to ...

Dr. Universe: Do trees still create oxygen and clean the air after their leaves fall off? – Nova, 8, Palouse, Wash. The trees that lose their leaves in fall, such as chestnuts, oaks, aspens and maples ...

Ever wonder what happens to oxygen levels when leaves fall off the trees? Joe lets us know how we are still able to breathe.

An aerial view of a river surrounded by trees (Brian Beckwith/Unsplash via Courthouse News) (CN) — Inland waters like rivers, lakes, streams and reservoirs need oxygen to survive, just like we do, but ...