GED Science: Introduction to Food Chains
Ecology is the study of interactions between and among living organisms and their surroundings. While ecology may seem similar to biology, in fact, ecology is a much broader science, and focuses on systems, and complex interactions in systems. Thus, the unit of study in ecology is very broad. Ecologists study the following systems:
Populations: Collections of organisms of the same species (e.g., a population of tree frogs).
Communities: Collections of living organisms that share the same geographic space (e.g., a community of living organisms in a forest, including beetles, rabbits, birds, and trees).
Ecosystems: Communities of organisms and their physical environment (e.g., the forest ecosystem, which includes beetles, rabbits, birds, and trees; as well as a certain temperature, soil pH, rain level, etc.)
Biomes: Large groups of ecosystems that share similar characteristics in terms of physical environment. (e.g., the deciduous forest biome, which includes all forests with similar characteristics).
These systems go from small to large. A population is a smaller system than a community, which is smaller than an ecosystem. A biome is a very large system. Another important thing to notice about the definitions is the difference between a community and an ecosystem. A community includes the living organisms that share a space. An ecosystem includes the living organism that share a space and the physical surroundings. Ecologists differentiate between biotic factors (the living parts) in an ecosystem and the abiotic factors (the non-living parts). This lesson will focus mostly on biotic factors within populations and communities.