Leaf burn has many different causes. One of which is sometimes pests as they could infect the plant.
It looks like it might be one of the list below.
Environmental leaf burn
Too hot / too dry
Bacterial leaf burn
Reaccuring every year
Too much/too little fertiliser
usually iron or manganese
It is responding a stressor, like not having enough light. Less light is the trigger for trees to loose their leaves in the fall. Those leaves change colour, because the plant cut off liquid to leaf. As the leaf stop making energy it shows it real colour. The colour it has without photosynthesis.
Your plant should be at your brightest window and have a ...
It is Araucaria araucana (see https://en.wikipedia.org/wiki/Araucaria_araucana), commonly called the "monkey puzzle tree" in the UK (presumably because attempting to climb it would be an prickly experience).
Its native habitat is in Chile at high altitudes (above 1000m).
It is hardy down to about -20C.
The small tree is a species of Ilex (Holly). There are many different species of holly. Not all have thorns. Not all are evergreen. Most are quite vigorous taking advantage of any opening to start to grow, especially around fertile soil. Ilex aquifolium, AKA English Holly is very invasive in many part of the North America. Bird eat the berries and ...
That leaf looks like it comes from some kind of oak tree. Like maybe a live oak? (But apparently there are many species even of live oaks). So, ... "Quercus something-us"
It isn't clear if your big tree - or your little tree - has leaves that look like that. Or is it both?
That last option seems most likely to me. It looks like the little tree is suckering ...
They will end up being nothing more than a nice looking mulch that will slowly decompose as all natural mulch do. It will not damage the soil, unless as other have pointed out they are salted peanuts. These shells, especially the pistacio shells are slow to decompose. If you plan to add a lot continuously you end up with a compost piles of shells that ...
Apparently you have not heard of any desalination processes,... as yes it can be difficult to remove, but not impossible, ... You can separate the soil from the salt, by boiling the salt minerals out of the soil, ... it is a lengthy process, but it will give you the desired results, ... certain types of salts are attracted to certain minerals, such as iron, ...