The effect Climate Change has on Plant Growth in today's world.
According to www.un.org, climate change is long term shifts in temperatures and weather
patterns. Over the last 30 years it has become a growing concern for many scientists and even
just regular people who first hand see the shifts in a drastic change in the weather, for
example Ireland seeing massive snow in February 2018. This climate change does not only
affect the Human species, but also other things such as plants. This review will look at the
effect climate change has on plant growth, and how that affects us.
Carbon dioxide levels have increased an immoderate amount in the last few decades. From
1980 to 2020 alone it has increased by around 40%. Studies where plants are watched in a
biome with a rising CO2 level has been done (FACE) studies. These studies concluded that it
had little effect on cereal grains, but are highly doubted due to some concerns about the
studies such as the length of the experiments and small sample sizes. However, it is
confirmed through many studies that water use in plants is directly affected from change in
climate. Transpiration is evaporation of water that occurs in plants when stomata are open for
CO2 and O2 while photosynthesis happens. Seasonal crop water requirements such as cereal
crops have adjusted to today's temperature will expedite plant maturity, decreasing leaf area
and leading to an overall reduction of water needs. Opposedly varieties adapted to higher
temperatures and more growing time water requirements would increase. However, stomatal
closure is an effect of the increase in CO2 we have seen (Kimball and Idso, 1983). Wand et
al. (1999) concluded in studies that stomatal closure was around 39% due to CO2. This
reduction can easily lead to a reduction in transpiration in the near future, thus impacting our
crop amounts globally.
Photosynthesis is also affected by the changes happening in the climate. The photosynthetic
properties of leaves developed at higher CO2 concentration differ from those developed at
the current CO2 concentration. The developments at a higher level of CO2 lead to an
abundance of nutrients produced, for example the plants were unable to use all of the
carbohydrates produced in this process.Water levels decreased due to CO2, and this caused
another decrease in photosynthesis (Wall et al., 2006). Different parts of the world essentially
can not keep up with the crop needs of humans due to a change in where crops need to be. It
also resulted in some extensions of plants which could not withhold these changes in what
they require. The nutrients available to crops are highly affected by a rise in CO2
concentration.(Plant Mol. Biol. 1997). Temperature also plays a role in Photosynthesis. We
know maize, leaf photosynthesis has a high temperature optimum of 33 to 38ºC (Oberhuber
and Edwards, 1993) it was also noted that photosynthetic rate reduced for each 1ºC increase
in temperature over 30ºC
While we heavily focus on CO2 levels when discussing plant growth, the Ozone plays a huge
role also. Global background tropospheric ozone concentrations are continuing to rise
(Ashmore, 2005). Ozone toxicity has become a growing issue in plant biomes. The soybean
has been extensively studied for the effects that the ozone has on it. It has been found that O3
reduces photosynthesis which is essential for plant growth and reproduction quality.
Subjection of soybean to higher O3 levels led to smaller leaf surface area and shorter plants
with fewer pods containing fewer and smaller seeds, therefore reducing reproduction of
plants. The Soybean also showed reduced signs of photosynthesis due to temperature.
It is important to note climate not only directly affects plant growth but also affects
surrounding factors such and changing the biome plants are in- soil ph and wind dispersal of
seeds for example. It also affects the insects which aid plants (Agroecosystems). Changes in
seasonal weather that has been documented plays a part in insect and animal lives and their
routines. Animals can often aid in the dispersal of seeds, further aiding in the reproduction of
our plants. When this cycle is broken due to climate change, we see a reduction in plants
which leads to a reduction in animals which causes a further reduction in plants, increasing
risk of extinction for both. Plant to insect interactions can be affected by increasing CO2
concentrations and this would have implications for insect management which can lead to
more parasites around to destroy plant systems.
Climate change; increasing trends in temperature, CO2, precipitation and O3, are having
impacts on agricultural systems around the globe. The lowering of crop production is causing
a shift in ecosystems everywhere. Plant growth has been stunted everywhere, and many have
required to be physically adapted by humans to withstand these conditions, however it may
not be long until that fails and ecosystems will fail.
Bibliography
● Drake, B.G., Gonzàlez-Meler, M.A. and Long, S.P., 1997. More efficient plants: a
consequence of rising atmospheric CO2?. Annual review of plant biology, 48(1),
pp.609-639.
● Hatfield, J.L., et al. (2011) Climate impacts on agriculture: implications for crop
production. Agronomy journal, 103(2), pp.351-370