We do not yet have quantitative estimates of the level of biodiversity at which change in ecosystem functions become significant for different processes or ecosystems and this is an active area. Biodiversity the effect of human interaction on ecosystems - Edexcel Biological factors affecting food security - Edexcel. Phosphorus Understanding Global Change They can be as small as a puddle or as large as the earth itself. . Abiotic factors include rocks temperature and humidity. Basically any living and non-living things interacting together can be considered an. Ecological systems have many biogeochemical cycles operating as a part of the system for example the water cycle the carbon cycle the nitrogen cycle etc. Carbon is constantly in the news. Ecosystems vary in size. All chemical elements occurring in organisms are part of biogeochemical cycles. Predator-prey cycles The numbers of predators and prey for ...