Wow, humans used different fire than nature, they used "Bad Fire", and old mom nature used "Good Fire", that explains it all. Fires started by nature automatically went out after the proper amount of burning, human fires just kept on burning forever without the proper "natural" sense to go out at the proper time. Joke as you wish but there is "good fire" and "bad fire". Many plants and animals have adapted to certain fire frequencies and fire intensities. Midwestern oak savannaas and prairies, for example, have unique tolerance levels for fire. Disrupt the "natural" frequency and intensity of fire and you have landscape change. Not to say landscape change is bad, its just landscape change.
Yeah, I'm going to joke about this because there is no good or bad fire, it is always the same physical and chemical reaction. also, it's no surprise that living things adapt to their environment like fire cycles. It is also guaranteed that there will be change and fire cycles are not exempt, with or without humans. It's enviro-bull to try and tag humans as the evil desert makers. Overall human effect on Earth is about nil, everytime she decides to burp a tiny amount, she undoes or outdoes the total human effect for all our history of habitation.
In a few hundred million years, when we can no longer see the planet Mercury in the heavens, the fire cycles will definitely be different and they will have changed many times between now and then.