Question

In what way is primary production relevant for global climate? How can we expect plants to react to an increase og CO2 in the atmosphere? What effects may we expect in herbivores? Explain.

Answer 1

Plants carry out the primary production known as primary producers / autotrophs.

Primary production is the synthesis of organic compounds from atmospheric co2 through the process of photosynthesis.

We all depend directly or indirectly on primary production. The main source of this energy is sunlight and the end point is reduced carbohydrates.

Primary production is highly responsive to variations in climate. Climate change includes change in temperature, precipitation, wind patterns etc.

Global warming refers to the recent and ongoing rise in global average temperature near earth's surface. It is caused mostly by increasing concentration of greenhouse gases in atmosphere (mainly co2).

This is causing climate pattern to change. This can effect the agricultural producers because agriculture and fisheries depend on specific climatic conditions. Temperature changes cam cause habitat ranges and crop planting dates which may hinder farming practices.

Rising co2 - the main driver for climate change could increase the productivity of some crops such as rice, Soyabean, wheat. But it may affect the length and quality of the growing season and farmers could experience increasing damage to their crops caused by rising intensity of drought, flooding amd and fires.

From recent report it is predicted the increase in co2 may improve the food production in the mid to high latitudes over the next few decades. Conversely the low latitudes could experience declining conditions. Beyond this if global temperature rise by more than 1-3 degree centigrade declining conditions could be experienced over a much larger area.

Another factor is nitrogen short supplies. Nitrogen is the primary controller of how much biomass is produced in am ecosystem. If nitrogen ia limited, the benefit of increased co2 is also limited.

Research shows that plant get some benefits early on from higher co2 but that start to saturate after the gas reaches a certain level.

The more co2 u have the less and less benefits you get.

While rising co2 might seem like a boon for agriculture, it may have negative effects like soil moisture deficit or heat directly damaging to plants. On top of that increased co2 benefits weeds that compete with farm plants.

Most herbivores die of host plant induced death in elevated co2 than ambient co2. Attack rates of herbivores by natural enemies will increase possibly because herbivores need to feed for a longer time in order to procure sufficient nitrogen.