There is a grove of red pine near where I grew up that was planted row on row about 15 feet apart. These trees are 70+ years old but most of them are only 7-8

There is a grove of red pine near where I grew up that was planted row on row about 15 feet apart. These trees are 70+ years old but most of them are only 7-8 inches in diameter. The floor of this grove is just red with pine needles, nothing else can grow and any animals are just passing through. Whenever I hear about planting trees for "carbon sequestration", I immediately remember walking through that forest and thinking how quiet and dead it felt.