Why Are Plants Important?

Plants are important because they provide many benefits to the environment and to us. They give animals food and shelter, help keep the air and water clean, and can even make cities cooler. An important example is pollinator insects, like bees and butterflies, which rely on specific plants and in turn help plants reproduce by spreading their pollen. If the specific plant disappears, the pollinator might also vanish because it cannot live on its own (Figure 1). This shows how plants are deeply connected to other living things in their ecosystem, and losing one species can affect many others.

Plants also make us feel good when we are around them. But sometimes, when we build cities, we need to cut plants down, which can cause big problems. When we lose too much vegetation, entire ecosystems can become unbalanced, leading to less biodiversity, soil washing away, and disruptions to food chains [1]. Unfortunately, cities are becoming so big that some plants are close to disappearing completely. These are called endangered plants. A plant becomes endangered when there are only a few left and the places they need to live, like forests or wetlands, are being damaged or destroyed. If scientists and communities do not take action, these endangered plants might even go extinct [2].

How do Plants Become Endangered in Cities?

There are many reasons a plant might become endangered, and the rapid growth of cities is one of the biggest problems. The process of building cities, known as urbanization, is speeding up, because over half of the people in the world lives in cities [3]. Sadly, growing cities can endanger plants in many ways. First, cities cause changes to the landscape, such as the development of buildings and roads, that split up plant communities. This means that the ecosystems are no longer connected, which isolates plant populations and makes it hard for them to reproduce. Another thing that can damage plants is climate change caused by human activities. Climate change can alter the environment in big ways, like when warmer weather comes at unusual times, causing plants to flower at the wrong time and confusing pollinators. In cities, climate change can be even worse—this is called the urban heat island effect. Urban heat islands are small areas within a city where there is lot of concrete (e.g., buildings) and very few trees, causing the sun to heat up the area, which then stays warm longer than more natural areas (To read more about plants and climate change, see this Frontiers for Young Minds article).

Another way that cities can impact trees is pollution from cars and factories, which causes changes to the soil and puts particles in the air. Pollution affects the plants’ health and their reproduction (e.g., they produce fewer seeds). Finally, in cities, humans often introduce plants and animals that are not supposed to be there and can become invasive species (see this Frontiers for Young Minds article for an example). Urban plants must then compete with these invasive species for water, food, light, and space, and they can become sick from new diseases. The damage done to plants is slightly different in cities around the world, but overall, these impacts mean there are fewer types of plants in cities, and fewer important pollinators, so many urban plants are struggling to survive [3] (Figure 2).

Learning About Plants to Help Save Them

Many endangered plants can only be found in very small areas. When these natural areas are cleared for new houses or buildings, this can put the species at risk of extinction. So, when a new development is planned, it is important to know which species of plants live in that area. This involves undertaking surveys to identify all of the species present, to understand the level of conservation and management required.

Next, scientists and developers need to make plans to save any plants that are endangered. The best option is to design new developments that do not require all of the plants in that area to be cleared. This can include building around the plants or planning buildings that incorporate the plants into their designs. When preserving and incorporating plants is not possible, scientists must find ways to save the plants and regrow them elsewhere. This can be done through plant propagation, which is when seeds or cuttings are taken from the plants and grown in a new location. To do this, plant scientists need to work out how to best collect seeds or cuttings, and what climate conditions the plant needs [4].

It is also important to study what other plants the endangered plants like living with, and whether there are any pollinators that the plants rely on to reproduce. All these things are important to make sure that the new populations of plants can be healthy and can survive for a long time. As an example in Perth (in Western Australia), a new airport is planned for an area that is currently home to an endangered plant (Figure 1). Before the airport can be built, scientists have been working hard to understand how to save the endangered plants, and they have been collecting seeds and identifying other areas nearby that would be suitable for these plants to survive in the future.

Helping Plants to Survive in Cities

To help endangered plant species survive, scientists must increase their numbers in areas that are not likely to be disturbed or turned into buildings in the future. This involves using scientific knowledge to grow these special plants and encouraging the community to plant them in locations with the right conditions, like temperature, soil, sunlight, and other plants [5]. One way to do this is to plant seedlings (juvenile plants) grown from seed or cuttings. Planting more endangered plants in suitable areas can increase their numbers and protect them from future human development (Figure 3A).

Another way is to move plants from a location that will be disturbed to another location that will remain untouched and where the plants can survive a process called translocation. Translocating plants from disturbed areas to safer areas can save the plants that would likely be killed during a disturbance (Figure 3B). Finally, scientists and the public can monitor the newly planted/translocated plants and their habitats to ensure they stay happy and healthy (Figure 3C). Regularly monitoring the plants helps scientists understand the health of both the plants and the surrounding habitat, and tells them if the plants need more support to stay alive.

Planting and translocating can be done together or separately, but monitoring is needed with both methods to ensure that the plants are happy in their new homes. Community events are sometimes held to allow the public to participate in planting or translocating endangered species. These events can be small or large and are commonly organized by local government agencies or not-for-profit organizations in nature reserves or other natural areas within urban areas. In dry cities such as Perth, these events normally happen around winter to give the seedlings and translocated plants the best chance of survival with more water available. Monitoring, on the other hand, does not require a large community involvement and can be done at any time after planting. Monitoring typically involves recording details like the plant’s location and health, and whether it has any seeds or flowers. The information gathered by community monitoring helps develop management programs to protect these species in the future.

Helping endangered plants survive in growing cities not only protects them but also safeguards other plants and animals that depend on them. By working together to plant and care for these species, we support their reproduction and help to restore a healthy ecosystem.

Glossary

Biodiversity: ↑ The variety of species and the connected interactions with each other.

Urbanization: ↑ The development of an area into a city environment, often due to a growing population.

Climate Change: ↑ The change of apparent global or regional climate patterns from the average or expected climate patterns.

Invasive Species: ↑ An organism (plant, animal, or fungus) that is not native to an area and that spreads rapidly and causes damage to an ecosystem.

Propagation: ↑ Using a part of a parent plant to establish new growth or a new plant population.

Cutting: ↑ A growing part of a plant (for example, a branch) that is cut from a parent plant and used to grow a new plant.

Seedling: ↑ A young plant typically raised from seed.

Translocation: ↑ The movement of an animal/plant from its original location to a new environment.

Conflict of Interest

The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

AI Tool Statement

The author(s) declared that generative AI was not used in the creation of this manuscript.

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