Seed Dispersal

Seeds disperse from their parent plants to increase the chances of survival and establishment of new populations. This is because once a plant has produced seeds, it must compete with its own offspring, as well as other plants, for resources such as nutrients, light, water, and space.

Dispersal helps to spread the seeds over a wide area, increasing the chances that they will find suitable conditions for growth.

Types of Seed Dispersal

There are many different ways seeds can disperse from the parent plant. Some common methods of seed dispersal are:

  • Wind dispersal
  • Explosion seed dispersal
  • Animal dispersal
  • Water dispersal

Diagram illustrating various methods of 'SEED DISPERSAL'. The graphic is divided into four sections based on the mode of dispersal:'Explosion': Depicting plant illustrations of Jewelweed, Milkweed, and Lupins with seeds bursting out.'Wind': Featuring representations of Maple and Dandelion seeds, designed to be carried by the breeze.'Animals': Showcasing plants and fruits like Blackberry, Tomato, Burdock, and Oak Acorns, which rely on animals for dispersal.'Water': Illustrating the Coconut and Cattail, plants with seeds adapted to disperse via water.Lines organise each plant illustration into its respective dispersal method. The background is predominantly white, with each dispersal method labelled in large, colourful fonts.

Wind dispersal

Dispersal of seeds by wind is a common method that many plant species use. These seeds are often lightweight and have structures like feathery bristles that help them to be carried by the wind over long distances.

The ability to disperse seeds by wind allows plants to establish populations in new areas and can help to ensure the survival of the species.

Explosion seed dispersal

Many plants use explosive mechanisms to disperse their seeds. This helps to ensure that the seeds are spread far away from the parent plant. When the seeds are mature and ready to be dispersed, they may be contained in a pod or other type of structure. As the seeds dry out, pressure can build up inside the pod, causing it to burst open.

This explosive dispersal can shoot the seeds out of the pod and into the surrounding environment. The seeds can be carried even further away from the parent plant by wind, water, or animals.

Animal dispersal

Animal seed dispersal involves animals carrying seeds away from the parent plant. The two main types of animal seed dispersal are internal and external.

Internal animal dispersal

Many plants produce fruits that are attractive to fruit-eating animals. These fruits often contain seeds, which are dispersed when the animals eat the fruit and then later defecate the seeds in a new location. This method of seed dispersal, known as internal seed dispersal, is effective at spreading seeds to new locations.

To protect them from damage during the digestive process, seeds are often coated with an indigestible layer. This allows them to pass through the animal’s digestive system intact.

A speckled bird perched on a bare tree branch, pecking at ripe, red berries. The background is a muted brown, likely representing a winter or late-autumn setting.

External animal dispersal

Some seeds have special coatings or small hooks that easily stick to the fur of animals. When the animals move, they transport the seeds away from the parent plant. Eventually, the seeds can fall off onto the ground, germinate and grow into new plants.

This method of seed dispersal is known as external seed dispersal.

Close-up of thistle-like seed heads glistening in the golden sunlight, with delicate frost crystals clinging to their spiky surfaces.

Water dispersal

Some seeds are adapted to be carried away from the parent plant by water. For example, coconuts have a thick, hard outer layer that helps them float on water and be carried to different locations.

Water dispersal is useful for various plant types, especially those in areas prone to flooding. It allows them to start new populations in new areas, which increases their chances of survival.

You’ve used 1 of your 10 free revision notes for the month

Sign up to get unlimited access to revision notes, quizzes, audio lessons and more

Sign up