The Effects of Atmospheric Pressure on Plants

Speed of Growth

• The speed at which plants grow is affected by atmospheric pressure conditions. At the 101 kPa pressure found in the Earth's atmosphere, each plant grows at its ideal rate. However, if you were to reduce this pressure, the plants would still grow, though not as quickly. If atmospheric pressure goes too low, a plant cannot survive due to the lack of gas exchange that can take place. Atmospheric pressure is important to the nutrition of growing plants.

Gas Concentration

• More important than the actual atmospheric pressure number is the gas concentration. In the Earth's atmosphere, oxygen makes up about 20 percent of the gases present in the air. This is a required element for plant growth. Even if you reduce or increase the atmospheric pressure, it is important to maintain the same amount of oxygen for plant growth, which is about 15 to 20 kPa, regardless of the amount of atmospheric pressure. To prevent flammability of the air, atmospheric pressure must remain above 30 to 50 kPa total pressure.

Water Plants

• The atmospheric pressure has a different effect on water plants than plants that grow on land. The lower the atmospheric pressure, the less dissolved oxygen is present in the water. Therefore, at higher elevations, water plants do not grow as efficiently as they do at lower elevations. If there are fewer water plants present at higher elevations, they can still grow because fewer plants require less oxygen in the water. However, water at higher elevations is often colder, which allows for higher concentrations of oxygen. The two factors often balance each other out.

Adaptations

• Unlike humans, plants are able to adapt to their environment and actually change their genetic makeup to survive in varying atmospheric pressure conditions, according to the National Academies Press. Plants can alter their metabolism to accommodate the varying gases present in different atmospheric pressure, surviving under pressures of less than 25 kPa. The plants may grow more slowly and may not achieve the same amount of growth, but they will still survive and produce seeds to create more plants.