ABSTRACT
This chapter introduces what we regard as the key basic ecological concepts relevant to agroecosystems. It is general knowledge that plants are extremely different than animals in that their energy-gathering organs are distinct from their material-gathering organs. An additional pattern of light capture in photosynthesis, recognized for centuries, has to do with the response of individual plants to different levels of light. Nitrogen-fixing microorganisms are central to the agroecosystem. One of the major constituents of protein is nitrogen (N), giving that particular element a key role in life's processes. Decomposers include a wide variety of organisms, from earthworms to bacteria, from millipedes to fungi. The decomposition process is inevitably complicated and highly variable from place to place. A variety of other microorganisms that live in soils are also important for nutrient acquisition by plants. Water in soil is strongly affected by soil particle distribution, which is why soil texture is a fundamental property to be considered when concerned with water.
