History has shown that eco systems are fragile things, which can be irreversibly changed, or even wiped out in the blink of an eye. We need to take the utmost care to ensure that we do not damage them. We should be trying to reduce the endangered species list, not adding to it.
I believe the eco system is very fragile. Species being transported to different continents become invasive and wipe out local wildlife. Human encroachment into native habitat risks altercations and the spread of disease. The bee populations are suffering mightily, and without their pollination, we could lose all kinds of plants and crops.
It comes from a bacteria and will transmit from animal to animal, not mattering if there are humans or not. In fact, the development of antibiotics is the only way to stop it. The spores dont die easily and need burning or powerful chemicals. Dramatic and unprecedented warming in the Arctic is driving sea level rise, affecting weather patterns around the world and may trigger even more changes in the climate system.
The ecosystem has survived for thousands upon thousands of years. Although Humanity has had a significant impact of different segments of ecosystem over the last couple thousands of years the ecosystem itself has survived. As can be seen in areas that were once devastated by human activity, when humans step back the system repairs itself in a short time. Life always finds a way.