Water will be a main nonliving part in an ecosystem, due to the organisms in the ecosystem relying on the water to survive, without this the population will severly dwindle and eventually die out. Climate is another, most plants can only live in a place with a certain type of climate, such as hot and humid or cold and rainy, if the climate were to change in an ecosystem this wold cause some of the plants to die out, and most will be forced to adapt. Finally we have the basic air, without air the whole ecosystem would die out, animals cannot survive without oxygen and plants cannot survive without carbon dioxide.
