Why are these tree branches growing downward?

Question

The trees on my property tend to grow their branches downward, like this:

It looks to me like they're just crowded and reaching for some sunlight, but I'm starting to worry about their health and ours (e.g., if that massive oak branch falls on someone). So:

1. Assuming the downward branches are an attempt to find sunlight, how much can I prune them back without harming the tree?

2. What can I do to promote the long-term health of my trees generally?

3. If I'm wrong about the downward branches, then what is actually going on?

Answer 1

Yes, they are "just" overcrowded and trying to reach some daylight.

When the only leaves on a branch are at the end, because the rest is too dark for anything to grow, the weight of the leaves will naturally pull the branch down.

The solution is to fell maybe half the trees or even more, to give the others room to grow properly. Or fell them all, and replace them with species that will stay small and survive being regularly pruned.

Answer 2

Dependant on the species you have there, is it feasible to coppice, [cut down to the ground] some of the trees in front and then 'lift' [clean the lower branches], from the taller trees.

Coppicing does not work on all tree species, but when it is possible, it prolongs the life of the tree by keeping it perennially young. This would allow you to periodically reduce some trees letting light in to the area.

Cleaning up the trunks of the taller trees in conjunction with coppicing, [if feasible], can prevent the 'stretched' limbs growing out, causing shade, and becoming weakened and liable to break and fall.

The area under the trees, with more light penetration, might then be amenable to shrub/bulb underplanting.

Thank you.