Ecology is the scientific study of interactions between organisms and their environment. There are biotic (living) and abiotic (non-living) factors that influence ecosystems. Producers, like plants, use photosynthesis or chemosynthesis to produce food from sunlight or chemical energy. Consumers rely on producers or other organisms for food and include herbivores, carnivores, and omnivores. Energy and nutrients transfer between trophic levels in a food chain or food web. Ecological pyramids show that the amount of available energy and biomass decreases at higher trophic levels due to only 10% of energy transferring between levels. Organisms also interact through competition for resources, ecological niches, pred