Only rangers, druids,and sometimes bards can do these things as is. D&D just has them be druid spells and gives them to rangers and bards. They were the only ones with the spells to track, heal, fade, and talk to plants, rocks, animals, or nature spirits
The question was with regard to an explicitly non-magical set of wilderness-themed abilities. I'm saying that tying those to specific character classes, rather than a separate system which characters of any class can take, has a conceptual awkwardness to it. The same way that fighters aren't the only ones capable of engaging in melee combat, it can be hard to justify why learning certain non-magical abilities is tied to a particular character class. That's why I mentioned thieves, since I recall a lot of people pointing to the idea that no one besides them could detect traps, hide in shadows, etc. as something that they had a hard time with.
Now, if a non-magical function is particularly niche, then tying it to a class - where a "class" is defined as a profession, i.e. something you
do rather than something you
are (and if that seems like an odd distinction to make, sorcerers always struck me as the latter rather than the former) - isn't that big of a deal. In that case, taking levels in the class is representative of engaging in niche training, i.e. multiclassing for a level or two if you just want to dabble in something. But broader non-magical abilities are difficult to conceptually hard-code into a class in a plausible manner. Tripping someone in combat shouldn't be something only a fighter can do, and learning how to make a poultice of notable efficacy shouldn't be something only a ranger can do.
Magic, I'll note, gets something of a pass; being entirely fantastic in nature, it requires a degree of suspension of disbelief that mundane abilities typically don't get. So if you say that a particular type of magic is limited to a specific class, it's often taken as
fait accompli that some aspect of the class relates to training in how to learn that style of magic (though I'll point to sorcerers as mild exceptions, again). In that case, questions of "how" and "why" are less important than making sure it's consistent in presentation, balanced under the system, etc. (Though it's worth noting that even for this, exceptions abound; I can't tell you the number of magic systems I've seen that use skills or feats to measure a user's progression, rather than tying it to levels in a particular class.)
That's why designing a system of non-magical woodland-themed abilities that
only rangers can use strikes me as a bad idea. Though as I noted before, the best way to square that particular circle (i.e. try and tie the ranger class to such a system while not making it exclusive to them) is to simply bake a lot of bonuses into the class that makes it easier for them to make use of that system.