Some philosophers deny that something can have value if no one is around to value it.
The animals and plants which are part of these ecosystems value them. It's not just about humans.
It's the old 'tree falling with no-one around to hear it, does it make a sound' pseudo-conundrum. Of course it does. The impact creates vibration. What we call 'sound' and 'hearing' is simply one way of sensing and interpreting that vibration. The vibration still occurs and there are plenty of living things around that sense it one way or another, including by what we call 'hearing'.
Humans are really just so up themselves. We're one little blip in the evolution of life on this planet. So much has come (and gone) before, so much will come after - and we won't last anywhere near as long as many other species.