The Environmental Benefits of Plants
Exploring the specific reasons why plants are so important for biodiversity, climate change, and more
Plants first emerged on Earth around 500 million years ago, 494 million years before people. They bring tranquillity and peace, stimulate senses, provide calm, and are scientifically proven to reduce stress. Plants also improve the air quality, and it is suggested that the way the toxins are removed from the air relaxes our bodies. It is widely accepted as fact that plants have an essential role in combatting climate change and benefiting the environment, but it might not be completely obvious as to why. In this article we are going to explore a few of the exact ways in which plants provide us with environmental benefit; whether it’s wildlife, carbon emissions, or water management.
One of the most widely attributed benefits of plant life on Earth, trees in particular, is their function of taking in carbon dioxide and producing oxygen in return. Beyond the obvious benefit of this providing us with the air we need to breathe, it also helps reduce the amount of carbon dioxide in the atmosphere.
Carbon Dioxide is formed from the burning and extraction of fossil fuels, and whilst being important in regard to absorbing and releasing heat from the earth’s surface, it has damaging consequences. One of these being the greenhouse effect, where gases such as carbon dioxide build up in the atmosphere, causing the Earth to become warmer than it would be naturally. These gases allow the visible light waves from the sun to pass through, but as they are reflected off the Earth’s surface, they shift to infrared waves. These infrared waves are then unable to escape through the layer of greenhouse gases in the earth’s atmosphere, trapping in the heat which is emitted from infrared radiation. This positive feedback loop, combined with the sharp increase in CO2 emissions since the industrial revolution, is the primary cause of global warming. A higher global temperature causes the polar ice caps to melt, which in turn causes the sea level to rise, leading to widespread flooding and habitat loss. As the temperature rises, local climates begin to shift dramatically, leading to many native species being unable to adapt to their new conditions, causing mass extinction. The climate shift can also cause more extreme and unpredictable weather, leading to droughts, heatwaves, and other extreme conditions. Trying to reverse the greenhouse effect and reduce the impact of climate change is the very reason why carbon emissions must be controlled.
Carbon sequestration is when carbon dioxide is absorbed and stored from the atmosphere in attempt to reduce its impact on climate change. This is both a naturally occurring process in trees and plants, and a technological process. Synthetic carbon capture and storage (CCS) is when carbon dioxide is separated from other gases in industrial emissions. Then, it is reduced and stored, unable to escape into the atmosphere. In the naturally occurring process, plants absorb carbon dioxide during photosynthesis, using it to produce glucose and oxygen, which are essential for survival. The carbon is then stored in the leaves, stems, and roots. Remarkably, plant-rich landscapes such as forests and grasslands capture approximately 25% of carbon emissions globally. It is reported that the total amount of carbon in vegetation, soil, and detritus is roughly 2,200 gigatons. This is why it is crucial that we look after our forests and green spaces, and shows how important it is that we plant more trees worldwide to maximise global carbon sequestration. It is reported that 1.5 million hectares of additional woodland are needed to help reach net zero carbon emissions.
Plants as a water regulator
Urban flooding is detrimental to both the environment and human infrastructure. It can cause damage to buildings and vehicles, power cuts, contribute to water pollution and sometimes even more severe consequences, such as loss of life. It also affects the environment by destroying natural habitats for wildlife, uprooting trees, and polluting rivers.
In urban areas, roads and pavements hinder this natural water absorption, and instead cause a rapid water runoff. After excessive rainfall, this can lead to flooding of urban areas if there aren’t sufficient suitable drainage systems in place. Cities therefore spend a lot of money in order to prevent flooding.
Natural areas are largely protected against this on the other hand, because of plant life, and its natural processes. This works by water being absorbed through root hairs and thin-walled epidermal cells, which is one of the fundamental activities of roots. The water is then distributed throughout the entire plant via the vascular system. Plants play an important role in stormwater runoff management by absorbing excess water after a rainstorm. This not only helps to prevent flooding, but it also contributes to cost savings for cities by reducing the need for expensive maintenance and pumping of excessive runoff.
Biodiversity is important for the environment for many different reasons. It helps support healthy ecosystems, creates fertile soil, provides us with oxygen, food, medicine and various other benefits, including the overall health and survival of all living organisms. It also provides vital support to ecosystems through pollination, seed distribution, climate regulation, purifying water, and more. Unfortunately, there are threats to biodiversity as a result of human activity, such as pollution, climate change, overharvesting, and more, all of which cause ecosystems to fall apart.
In February 2023, Defra (the Department for Environment, Food and Rural Affairs), announced the introduction of a new scheme called Biodiversity Net Gain. It states that any development project in England will be required to compensate for all biodiversity lost during the project, by incorporating a minimum of 10% additional biodiversity to achieve a net gain. The goal of this is to promote the restoration of nature, and enhance climate resilience, by establishing additional green spaces. Plants and trees are vital in creating a biodiverse environment, and are essential parts of any ecosystem, offering shelter and food for the many different life forms that live within it. Creating and promoting a biodiverse environment, through the addition of plants and trees will help to preserve our planet for future generations.
Plant decomposition and soil health
Whilst decaying plants and trees do emit carbon into the atmosphere, there is a direct benefit to health of the soil beneath, even after a plant has died. Dead plants release nutrients into the soil through the process of decomposition. The build-up of decayed plant material provides healthy, fertile soil for more plants to grow. Humus, the organic matter in soil, represents the ultimate stage of decomposition for plants, and stands out as the most efficient substance for enhancing soil quality.
When plants decompose in the same soil where they grew, nutrients and minerals return to the soil, preparing it for new plant life. This process is called mineralisation. Earthworms and other organisms help in the decomposition process by mixing and aerating the soil, resulting in topsoil being formed. The continuous breakdown cycle serves as a slow-release fertiliser, always providing plants with essential nutrients. However, if dead plant material is removed from its original location, and moved elsewhere, the nutrients and minerals are lost from the soils where they originated. This results in these soils becoming increasingly incapable of sustaining new plant life. Allowing dead plant matter to decompose in place, enhances the fertility of your soils. Planting and maintaining green spaces helps create a circular environment, where the existing plant life helps encourage the growth of new plant life.
Tips to maximise environmental benefits
There are a number of ways in which you can influence and enhance the benefits of a green space on the environment. A lot of this is down to the choice of plants for a project.
Using native plants, which are plants that occur naturally within a particular area, is a great way of maximising the environmental benefits to the area when planting a garden scheme. Native plants have co-evolved with native wildlife, such as bees, butterflies, and birds, and support these local ecological systems. This greatly increases the compatibility and the usefulness of the green spaces to the wildlife. Native plants are also generally lower maintenance than their exotic counterparts, as they naturally occur in the region, so they’re better suited to establish and thrive in the specific soil and climate. Another thing to consider when choosing plants for a garden scheme is to ensure that you are choosing plants that will not only be able to thrive in the current climate in which their planted, but the future climatic properties of the area in 5-10 years’ time. Climate change is dramatically shifting the temperature, precipitation, and weather patterns of our ecosystems, so it’s a good idea to select plants that can better cope with the changing climate. Selecting plants that are hardy, drought tolerant, and suited to higher temperatures is advised, as this will future-proof green spaces, and ensure that there is plant life that can survive in the future climate. Climate change is often seen as a topic for the future, but signs of its consequences can already be seen all over the world. 2023 was the hottest year on record, and globally, the temperatures exceeded the average for NASA’s baseline period by approximately 1.2 degrees Celsius. Antarctica experienced an annual ice loss of 151 billion tonnes, while there were more frequent wildfires in places like Australia, California and Greece. A lot of native plants are being affected by climate change, leading to more non-native species being planted, because of their ability to grow in the higher temperatures and extreme weather conditions. It is reported that one in five plant species are threatened in the UK. For example, Athyrium distentifolium, commonly known as Alpine lady-fern and found in the Scottish mountains, is losing the necessary snow cover essential for maintaining its moist habitat. Alternatively, we can ensure that there are green spaces capable of surviving the future climate, by planting drought tolerant, hardy species. Examples include Abelia × grandiflora, Ceanothus, Hylotelephium, and Myrtus communis, which are all capable of withstanding the challenges posed by rising temperatures.
Other sustainable initiatives
Additionally, there are a few other practices that can be employed in order to make planting even more environmentally friendly. Planting using compost made without the use of peat is one of the biggest ways in which a landscaper or plant grower can make a positive difference to the environment long term. Whilst peated compost makes a very effective growing medium, the harvesting of peat has a negative impact on the environment. In their natural state, peatlands are capable of sequestering 33% of global carbon emissions, and storing them in the ground, preventing their contribution to the greenhouse effect. When we harvest peat however, we must dig up these peatlands, which damages them. It means that not only does the carbon stored in the ground get released into the atmosphere, but the peatlands become less effective at further sequestering carbon dioxide in the future. With less than 20% of the UK’s peatlands remaining in a near-natural state, it becomes imperative to seek alternatives. Greenwood has taken a significant step by transitioning to growing 100% peat-free, Using alternative materials such as coir, which is made from coconut husk, as well as tree bark, in order to grow plants whilst using regenerative materials with a much smaller impact on carbon emissions.
Another way in which landscaping projects can provide benefit to the environment is through the use of Sustainable Drainage Systems, or SuDS for short. These are innovative, ecologically-friendly systems for managing surface water runoff in urban areas, promoting sustainable water management and minimising flooding risks. SuDS work by using a series of techniques that collectively organise a management sequence. As water flows through the system, rate of flow is managed and pollutants are extracted from it. In essence, SuDS delay water that runs off a site, and enables a natural process of pollutant decomposition to occur. Examples of SuDS include green roofs, ponds, permeable pavements, underground storage, and soakaways. Other benefits of using SuDS include water quality management, by reducing the amount of water entering combined sewers, as well as filtering out pollutants. Additionally, they capture and repurpose rainwater, storing it, filtering it, then making it available to repurpose for regular household activities. They also increase biodiversity in urban areas by creating habitats for various plants and animals, such as ponds.
To find out more about Greenwood’s sustainability efforts, click here.