well, I wouldn't say trees are really overburdened, if you look at the current loot list.
5-6 items:
Bearded Rock (Grade 1)
Black Brush (Grade 1)
Drybone (Grade 2)
Emerald Moss (Grade 2)

Only 4 areas have a loot list of 5-6 while the rest are 3-4, excluding catalyst. Gathering nodes need more variety in order to prevent one material being gained in to much surplus over another. if anything every area should have 5-6 items to mix it up. With the way gathering is atm, it's just way to easy to accumulate 3-4 stacks of a single item of any grade over the course of 2-3 hours. I mean ok you can say that 5-6 is really 10-12 because of +1, but at Grade 1/2 for someone who's just starting to play is that really an issue to their inventory load, at that lv the variety they obtain really doesn't effect as much as it would a higher lv.

I know this may sound unpopular, but for those who have seen the whole plot line this will be a spoiler for those who haven't done the class quest yet. Since the concept of a botanist isn't to chop down a tree but to gather the dead parts of the tree while leaving the living parts unharmed. What if they added "decayed" loot which could be traded in for some sort of blessing for cleaning up the environment. So like rather then just getting "this chop damaged the item" instead you start off with a 95/5 ratio of obtaining the item, so you cut the rosewood log and obtain it, after 10-20 cuts the ratio changes to 90/10, and it keeps going down as long as you are cutting for. At a certain point while you may succeed at cuts you'll receive a "decayed log" or "decayed branch" rather then the appropriate item. The quantity would always be one and there would be no +1 version of it.

Basically what could be done with these is you trade them to a sepcific NPC that gives you "Botanist Blessing" currency which can be used to effect your gathering yield.
Off the top of my head you could recieve the following blessings(only able to use one while hitting a certain "Botanist Blessing" overall cap will increase the amount of blessings you can have active.

Blessings could come in two forms, you have the potent instant blessings which take effect as soon as you purchase it, or the abilities which require a perpetual cost of MP but only provide 1/4 or 1/2 the strength of the instant ability.

Examples of this would be:
Instant "Golden Touch" Increase rate of HQ gathering by 25% Duration: 1hr
Ability "Golden Hands" Increases rate of HQ gathering by 5%
Instant "Steady Touch" Grants a 50% chance at +1 yield for all items Duration: 1hr
Ability "Steady Hand" Grants 15% chance at +1 yield for all items
Instant "Wood's Call" increases rate of obtaining wood based loot by 25%
Active "Wood's Desire" increases rate of obtaining wood based loot by 5%
Instant "Hunger's Call " increases rate of obtaining food based loot by 25%
Active "Hunger's Desire" increases rate of obtaining food based loot by 5%

The general idea is that creating decayed loot would decrease the amount of materials that would enter the market, but it would encourage gatherers to obtain them in order to obtain abilities that will improve their specified target when they want to gather items again.

As gatherers we should want larger loot list, sure we might want a specified item, but just because it's not something we want doesn't mean another person won't want to use it. The whole concept behind a gatherer is to obtain a large variety of items and then either use them ourselves or sell it on the MW to make gil. While we prolly won't see any truly major changes til 2.0 I do hope that with upcoming hamlet they will give us some interesting challenges when it comes to gathering for the sake or our grand companies lol.