I do not fully understand this question...
But just out of experience would you say that plants vary a little or a lot in their efficiency at producing joules for human consumption. And could you suggest reasons for the variation?
This site may help you.
http://www.energyquest.ca.gov/story/chapter01.html
Hmmmm. Some plants produce a lot of cellulose, and humans cant digest any of that. Plants produce oils, sugars, and some protein, and humans can digest those.
Plants do vary in their efficiency at producing joules for human consumption. Some plants are more efficient than others in converting sunlight into usable energy, while others may be less efficient. The variation in efficiency can be attributed to several factors:
1. Photosynthetic efficiency: Different plants have varying capabilities to capture and utilize sunlight for photosynthesis, which is the process by which they convert sunlight into chemical energy. Some plants have evolved to be highly efficient at photosynthesis, maximizing their energy production.
2. Metabolic processes: The efficiency of a plant's metabolic processes can also affect its energy production. Some plants have more efficient biochemical pathways that allow for better energy conversion and storage.
3. Genetic factors: Genetic variation among plants can influence their efficiency at energy production. Some plants may possess genetic traits that enhance their ability to convert sunlight and nutrients into usable energy.
4. Environmental conditions: The availability of resources such as sunlight, water, and nutrients can impact a plant's energy production. Plants growing in optimal conditions with access to abundant resources are likely to be more efficient at energy conversion compared to those in less favorable conditions.
5. Adaptation to specific environments: Different plant species have evolved to thrive in different environments. Plants adapted to specific ecological niches may have traits that enhance their energy production in those particular conditions.
It's important to note that plant efficiency at producing joules for human consumption can also be influenced by agricultural practices, such as the use of fertilizers and irrigation, as well as the quality of soil and climate conditions.