What determines the sustainability of an ecosystem? What can upset the balance even in sustainable communities?

The stability of natural ecosystems, their existence for a long time depends on the diversity of species living in them. The more species, the more complex the food chain, the more sustainable the ecosystem. The disappearance of one species will not lead to the death of the community. The species that feed on it will find new food sources. A sharp increase in the number of any population is limited by an increase in the number of predators, parasites, pathogens.
But even in stable communities, a person can upset the balance. For example, deforestation over a large area leads to the destruction of not only trees, but also some species of herbaceous plants, animals, fungi. As a result, swamps or wastelands appear in place of the forest.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.