Effects of Climate Change on Plant Growth Dylan Sharma

Effects of Climate Change on Plant Growth

Dylan Sharma (Year 10, Churchill)

This article will present scientific evidence for the way plants adapt to climate change and research on the ways plants develop in order to sustain themselves whilst experiencing climate change.

EFFECTS ON PLANTS

Climate change is having a significant effect on the growth of plants. The number of days per year in which a plant has the right conditions to grow within the next 80 years could decrease by as much as 11% due to climate change [1]. This would highly affect food production, as well as many farmers, and low paid workers who depend on the crops for food. The main cause of this decrease would be the large increase in CO 2 levels due to the increase in temperature, as the high temperatures increase the amount of water vapour which amplifies the greenhouse gases. The Earth’s average temperature has increased by 0.8 degrees in the last 200 years [4], but has only started rapidly increasing in recent times due to new technology and infrastructure which increases greenhouse gas emissions. This is due to natural combustion processes such as respiration and decomposition, and man-made processes such as burning of fossil fuels and deforestation. This leads to less photosynthesis which takes in carbon dioxide from the atmosphere to change it into oxygen, resulting in more carbon dioxide remaining in the atmosphere.

Research has shown 1 that if the temperature of the earth’s atmosphere increases, then the number of freezing days will also decrease. Freezing days are extremely crucial for the plant as they are normally the days in which plants don’t grow due to lack of heat. This is because a plant needs an optimum temperature in order for it’s enzymes to work; if it is too cold the enzymes won’t function well and if it is too hot the enzymes would denature, meaning the enzymes have to be at a perfect temperature in order to function well. If freezing days decrease by 7% then there will be a positive increase of growth in the plants [1]; however, too much increase in temperature would mean the water availability for the plant would also decrease. This is because there would be more energy to transfer water into water vapour, which means there would be water on the ground less consistently available. As water is one of the key reactants for photosynthesis it is extremely important for providing energy which helps the growth of the plant. Overall, the temperature increasing or decreasing is bad for plant growth due to the enzymes not working efficiently; however, too high an increase in temperature could also lead to lack of water supply due to evaporation which is greater than the effect of denaturing of the enzymes due to too high temperatures.

Another effect of climate change is the effect on forests throughout the world. Temperature increase reduces plant growth, as the water supply will be minimal and the enzymes may denature, which is seen through deserts such as the Sahara where the only plants living there are cacti due to their adaptations to the decreased in water supply. Forests are an essential provider of food and habitat to thousands of species of animals. These animals depend completely on the forest for food and a home. Increased temperatures would mean that the number of stable trees would decrease substantially and many habitats will be lost resulting in a decreasing population of animals and birds essential to the food chain and our ecosystem.

In order for plants to react to climate change, they have to adapt to the change in CO 2 levels in the atmosphere. However, research showed some plants which are older find it harder to adapt to climate change and therefore are highly affected by the increase in temperature levels, leading to an increase in CO 2 levels [1]. This is because older plants are a lot slower growing and flowering than younger plants as they respire and carry out photosynthesis 1 at a slower rate. As well as this, the older plants need more water to survive and as there has been a decrease in water due to the rise in temperature the older plants struggle to adapt 1 . Essentially, this means the older the plant, the more difficult it is to adapt and therefore much more likely to die from climate change.

Figure 1: The effect of climate change on crops (Source: ScienceDaily)

ADAPTATIONS

Plants can adapt to an increase in CO 2 levels by adapting parts of the leaves respiratory system to stop CO 2 from entering. Studies show that when a plants in areas of high carbon dioxide concentration, have fewer stomata [2]. The stomata is a tiny opening located on the lower epidermis of the leaf to allow gas exchange. This technique is used to control the carbon dioxide used for photosynthesis. As photosynthesis is extremely crucial to the plant, the stomata in the leaf play an extremely important job. The stomata’s main purpose is for gas exchange, and therefore needs to control gas going in and out of the leaf so the amount of CO 2 . The stomata also need to make sure the carbon dioxide, which is highly concentrated, isn’t all used up at once and isn’t overused in the plant. Stomata is also important for regulating water loss as it closes during the night to stop water from being released, which helps with maintaining water if there are high levels of CO 2 , to reduce the chance of it being a limiting factor.

Plants have also adapted to the increase in heat due to the increase of CO 2 in the atmosphere which stops constant water sources. Plants have an enzyme inside the plant called rubisco. Rubisco breaks down CO 2 however when the temperature is high it breaks down O 2 instead due to lack of energy [2]. This is because the water source is a reactant in photosynthesis and creates energy for the plant; therefore, if there is little water, there will be little energy. Plants have adapted to this by locating the rubisco inside the tissue where it is protected from the heat and the enzyme can break down CO 2 . In a study by a team of scientists[2], they put several different crops in a CO 2 rich environment to see the effect. The high CO 2 environment reduced the amount of zinc, iron and protein in the crops which are essential to the growth of the crop. This clearly showed the negative impact of CO 2 on the crops and can significantly harm not only the crops but also animals eating the crops as they could lack the nutrition necessary to their health. This is because crops contain the minerals such as calcium, which is beneficial to bone strength as well as helping with blood clotting, and helps our heartbeat by due to its role in the contraction of the heart to increase the blood flow rate. Plants also contain magnesium which helps with regulating muscles and nerve functions.

Seasonal plants can adapt quickly to climate change. This is because these plants are used to rapid changes in the environment due to seasonal change. A study was conducted by a scientist called Steven Franks in the Syrian desert to observe the effects a dry spell has on the way plants go about their flowering process 3 . The scientists dissected their seeds in order to observe the changes that had taken place in order for the crops to survive. The scientists found a rapid shift in the time of flowering, in which the plant had changed its flowering time by over a week to when there was a short wet spell in order to sustain a healthy flowering; as the plant originated from the California marsh and was used to a constant supply of water this was particularly impressive and emphasises the extreme adaptations plants have to take to survive climate change. This meant the plant would have grown effectively with enough water supply to gain enough energy to sustain itself as well as using it’s potassium, phosphorus and nitrogen (the three essentials to flowering) efficiently.

Due to the recent COVID-19 outbreak, everyone around the world has been forced into quarantine in order to stop the spread of this deadly virus; however, COVID-19 has had a positive impact on the environment. The worldwide quarantining has led to a reduction in carbon dioxide due to fewer factories and workplaces being active, meaning less workplace-related combustion is taking place which would have released huge amounts of carbon dioxide. This carbon dioxide would have affected the plants as plants won’t be able to respire due to the loss of oxygen. Furthermore, increased amounts of carbon dioxide leads to a reduction in zinc, iron and protein which are extremely important to the growth and development of the plant. Therefore, ironically, this COVID-19 outbreak is extremely helpful to plant growth and health.

CONCLUSION

In conclusion, plants are affected heavily by climate change by temperature increase and an increase in carbon dioxide emissions. Also, plants have very effective ways of adapting to climate change such as: reducing open stomata and changing flowering time to help with the growth of the plant. These techniques of adaptation show that climate change affects the plants; however, they can survive through adaptation.

BIBLIOGRAPHY

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5. https://time.com/3916200/climate-change-plant-growth/ Worland, Justin. “The Weird Effect Climate Change Will Have On Plant Growth”. June 11 2015.

https://medium.com/@thunsarzynski/plant-adaptations-under-a-rising-co2-level-feat-climate-change8f5accd1f213 Sarzynski, Thuận. “Plant adaptation under a rising CO2 level (feat Climate Change)”, Mar 2 2019.

https://www.scientificamerican.com/article/many-plants-can-adapt-whe/ Biello, David. “Many Plants Can Adapt when Climate Goes against the Grain”. January 9 2007.

https://www.theworldcounts.com/stories/Temperature-Change-Over-the-Last-100-Years Larsen Esben “Is it getting too hot, or what?” 2020

https://www.oneyoungworld.com/blog/what-effect-covid-19-climate-change Pareja Jauregui “Is it getting too hot, or what?” 2020