Summary of Ecosystems and Biotic Communities Several aspects were covered in this lecture: o Important terms that refer to certain interactions and dimensions.This can alter the species composition of the community and affect the balance of the ecosystem.The importance of the trophic niche includes the functional role of an organism in the food chain, as predation causes the death of prey, while parasitism affects the health of the host.Parasitism, on the other hand, affects the health and success of hosts, potentially reducing their numbers or altering their behavior, thus affecting interactions between other species.The trophic niche determines how species interact with each other and affects the stability of the ecosystem.Amnesia is an interaction where one organism negatively affects another without benefiting from it, and the harmful organism also benefits from its effect on the other organism.This is due to the abundance of plants and the scarcity of herbivores most of the time, which reduces the need for competition for resources, which leads to symbiosis (cooperation) and facilitation.o The importance of trophic niches and the environmental factors that determine species distribution.