Which species have I noticed are having the hardest time surviving?

The most obvious ones having a hard time are mountain Trees. They are easily observable, not like things like squirrels where even though 10% of normal squirrels might be happening some places how would you know if you even see one or two?

But, it is obvious that ultra-violet rays and not enough rain and sometimes smog or fires are playing havoc with high elevation trees especially. It is observable from southern to northern California, throughout the Sierras and even at times up into Oregon.

So, it is likely a major die off is happening in larger forest trees like Oaks, pines, and firs especially at certain elevations (higher ones) or where water tables are low throughout California. This has been observable for years now, ever since we have been in a Drought in the entire Colorado River from the State of Colorado to Mexico. Also, for example, in Yosemite all the smaller streams in the valley have already dried up so Only pretty much the Merced River is running. However, all the biggest falls like Bridal Veil, Yosemite Falls and Vernal and California Nevada falls were all still running and people were swimming in many of the upper sections of the Merced River while I was there and running small rapids on floats of various kinds about 1 week ago now.

But, if the trees are having a hard time so are the ants and any insects associated with trees too. This is a given. However, some things like pitch canker and bark beetles are likely okay because of the trees being weaker they can attack them more too.

So, there is this general degradation of life surrounding trees in California that I have observed since around 2000 or before related to the droughts from Colorado into California that at least in the Colorado River basin areas have been ongoing since 2000.

And the droughts throughout parts of California have been long too and could like in 1862 possible trigger another Ark Storm off the Pacific like it did with the droughts before the 1862 flooding somehow.

But, being aware of what is happening to the trees is helpful in knowing what is also happening to all species like Squirrels, and insects and birds also associated with trees in California, Nevada, Arizona, Colorado and Oregon.