Wednesday, 21 September 2011

Plant responses to global change: consequences for food security

A presentation from Ros Gleodow Assoc Prof from Monash University, at the August Lighter Footprints meeting.

Ros outlined her research into the impact of climate change (increased CO2, temperature and reduced water) on certain plants.

In general in high C02 conditions, the plants produce more woody growth, and fewer leaves, and those produce less protein (associated with the ease of producing carbohydrate so less enzyme required) and a slowing of the expected growth as the amounts of CO2 increase, as plants adapt.

Drought conditions in addition lead to decrease in overall production. As a bonus in high C02 conditions, the leaves also reduce their stomatal openings which has the benefit of limiting the transpiration of water, increasing the efficiency with which they use water

As protein in the leaf decreases, this leads to lower percentage of protein in seeds – and reduced gluten. This is likely to directly reduce the ability to make bread from those grains. This is also not good for animals that eat the leaves and grass themselves  as the proportion of protein is lower. Grazing animals will need to eat more grass to get the same amount of nutrition; koalas will need to eat more leaves.

One of the side effects of a plant requiring less protein to be used for photosynthesis, is the redeployment of that protein into defence, eg making cyanide. (Some plants do this, some do not)

Casarva is one such plant used very widely around the world as a staple, which at the current levels of cyanide they produce is already causing significant disability (Konzo) and research shows that higher C02 and drought conditions both increase cyanide significantly. (There is also research into how to eliminate cyanide in preparing the food). Also being researched by Ros is Sorghum. Ros has provided links on this issue for the website below.

External links:

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