“Some California forests have more than 1,000 trees per acre when 40 to 60 trees per acre would be ideal. These overcrowded forests are filled with dead trees, piles of logs, and thickets of small trees.” This is from a 2018 SF Chronicle article. https://www.sfchronicle.com/opinion/openforum/article/Why-California-burns-its-forests-have-too-13385872.php
This is a result of 40 years of stopping people from cutting down trees. Where I am, it’s even difficult to cut trees on your own property. You’re allowed two a year regardless of how large your property is - and if you want to cut certain types of trees, you need an arborist’s report. I know someone who recently bought a 10-acre parcel that hasn’t been maintained for the past 50 years. He’s cleared out probably close to a hundred truckloads of poison oak, fallen branches, dead shrubs, etc. Just yesterday, with 3 friends with trucks helping, they probably removed 20 truckloads. But cut a tree and neighbors complain. If you have a quarter-acre lot you can cut two trees; if you have a 10-acre lot, you can cut two trees (without going through a lot of governmental rigamarole).
Here in TN it’s so different—you just do it. I moved here 32 years ago and bought a one acre wooded lot with a house. First thing I did was have an number of encroaching trees removed. About a year ago my next door neighbor had a very large one in his front yard removed without seeking approval from anybody. I live in an unincorporated area 22 miles west of downtown Knoxville.