ABSTRACT
Soil nutrients, water, carbon dioxide, and sunlight are combined to form organic matter during photosynthesis. During a production process, each inflowing ingredient carries energy of a different type and quality. Some energy is degraded and flows out through the heat sink. These energy transformations during production processes are an example of work. In more complicated systems, such as the forest, where there are several stages of production and consumption, there is more than one kind of net production—for example, net wood production, net litter production. Sunlight is the limiting factor for photosynthesis. An example of limiting factors in Florida is the shortage of plant nutrients in the sandy soils—especially in those soils where the cover materials have been removed. This shortage limits the growth of new plants. In many Florida soils, nitrogen is the limiting factor to plant productivity. With less energy, the carrying capacity is less. Any limiting factor can limit the carrying capacity.
