The more species in the biogeocenosis, the more trophic connections. The more trophic links between species, the more stable, complex and diverse the food chain (for example, if there is suddenly a crop failure of the fruits of one plant, first-order consumers will quietly switch to another, and their number will change slightly). The stability of biogeocenosis directly depends on the number of components (species) that can support its functioning when changing certain environmental conditions.
Usually, agrocenosis is taken for comparison. There is very little biodiversity, this system is extremely unstable. Indeed, if a person abandons his agrocenosis (garden, field, artificial reservoir), he will quickly collapse, will be replaced by a natural biocenosis. Still, the opposite is true: in all biogeocenoses that are considered unstable, there is very little species diversity. In a mountain cave, for example, in the Arctic desert.
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.