Nutrient Dilution and Climate Cycles: concerns of declining plant nutrient balances
In an article in the London Times (May 04 2020), entitled ‘Insects fall prey to diet of junk food’, Rhys Blakely draws attention to research at Oklahoma University that raises concerns about climate change and nutrient dilution. This suggests that higher levels of atmospheric CO2 appear to be stimulating plant growth, but that this vegetation lacks vital nutrients and its poorer quality has led to numbers of many insect species falling sharply. The researchers say the phenomenon could ultimately pose a challenge for all animals that consume plants, including humans.
“The greenhouse gas CO2 is heating the Earth and acidifying its oceans, but it is also the main ingredient in the sugars, starches, and cellulose of plants,” Michael Kaspari, the senior author of the paper, is quoted. “When we pump the atmosphere full of CO2, we build more plants. But, with no additional nutrients to fertilise them, the nutritional value of each bite is diluted. Mouthful by mouthful, the prairie provides less and less food to the grasshoppers. Hence, their decline.” They are eating the equivalent of junk food.
Read the original article: Ellen A. R. Welti, Karl A. Roeder, Kirsten M. de Beurs, Anthony Joern, and Michael Kaspari. 2020.Nutrient dilution and climate cycles underlie declines in a dominant insect herbivore. Proc Nat Acad Sciences USA,117, 7271-7275;
The Times also quotes an article in Science that cited separate work carried out by Samuel Myers at Harvard, who in 2014 showed that wheat, maize, rice, and other major crops grown under higher carbon dioxide levels tend to have less nitrogen, phosphorous, sodium, zinc and other nutrients. It is thought that plant growth could be stimulated by the added carbon in the atmosphere, but that the roots are unable to keep pace and fall short in supplying other elements.
These are potentially serious issues, do any TAAI members have experience of nutrient dilution? Please let us know.
