The number of trees required to produce enough oxygen for one person in a year can vary based on several factors, including the species of trees, their age, climate conditions, and the individual's oxygen consumption. The specific oxygen production of trees can vary widely.

As a rough estimate, a mature leafy tree is often cited as producing about 100 to 200 kilograms (220 to 440 pounds) of oxygen per year. However, this number can vary significantly based on factors such as tree species, climate, and local environmental conditions.

The average person consumes about 550 liters (19 cubic feet) of oxygen per day. This is equivalent to approximately 200,000 liters (7,000 cubic feet) of oxygen per year. To calculate the number of trees required, we'd need to know the oxygen production rate of the specific tree species in the specific conditions.

As an illustrative example, if we take a conservative estimate of a tree producing 100 kilograms of oxygen per year, it would take roughly 20 to 30 mature trees to provide oxygen for one person for a year. However, these numbers are very approximate, and actual values can vary.

It's important to note that while trees contribute significantly to oxygen production, the majority of Earth's oxygen comes from phytoplankton in the oceans. Forests and trees play a crucial role in maintaining a balanced environment and supporting biodiversity, and their contributions extend beyond oxygen production to carbon sequestration, temperature regulation, and providing habitats for various species.