Seed Dispersal – Different Methods

Introduction of Seed Dispersal

All plants require water, sunlight, and space to thrive. Because its parent is already using the resources in that position, a seed cannot receive the items it needs to grow if it falls directly below it.

As a result, seeds must relocate in order to obtain the materials required for growth. Dispersal of seed is the term for this type of relocation.

Seed Dispersal:

Seed dispersal is an adaptation mechanism found in all seed-bearing plants that help to ensure the germination and survival of some seeds in adult plants by moving or transporting seeds away from their parent.

Seeds lack the basic structures and innovations that allow animals to travel from one location to another, such as legs or wings. As a result, different mechanisms for distributing seeds to new areas arose.

Seed Dispersal by Wind:

Some plants have evolved seeds that move from one location to another using wind power.

Seeds that are disseminated by the wind have a number of characteristics that enable them to succeed in this technique.

1. Compared to other seeds, they are usually lighter and smaller. This allows the wind to easily take them.
2. They feature specific air-catching structures, such as wings or fluff. These features lengthen the seed’s time in the air and enable it to fly great distances.
3. Some seeds, such as those generated by maple trees, can travel up to 180 meters, while others, such as those produced by dandelion plants, can travel up to 500 miles.

They are mass-produced in vast quantities because very few seeds transported by the wind have the chance of reaching favorable locations.

Disadvantages of this Technique:

1. The majority of seeds will die due to a lack of adequate living conditions.
2. The endosperm of these seeds is smaller in order for them to be smaller and lighter. As a result, they have less nutrition to survive on, and many will never establish themselves.

Seed Dispersal by Animals:

Another seed dispersal approach is to use animals to transport seeds to suitable sites.

Plants utilize a variety of techniques to entice animals to carry their seeds.

1. Consuming seeds as their food.

a. Fruits can have seeds embedded in them.

Fruits are attractive to birds and mammals because of their vibrant colors and nutrient-rich content.

When the animals defecate or spit out the seeds, they distribute them.

b. The seed itself might be an appealing food item for an animal that forages for winter food (example: squirrels and acorns).

Any seed that the animal forgets has a chance to germinate and grow into a new plant.

2. Seeds can also use animals to their benefit by becoming

Seeds can develop specific structures, such as burs or hooks, that allow them to become entangled in the feathers or fur of an animal and be moved to other areas.

While seeds created in this manner can be produced in vast quantities, they will never disperse unless they come into contact with an animal.

Examples include burdock heads with hooks, Wood Burdock, and Arctium nemorosum.

Seed Dispersal by Fire:

Dispersal of seed by fire differs significantly from other methods of dispersal. Because fire destroys the living plant material in any region, it creates ideal conditions for new seeds to germinate.

As a result, fire disseminated seeds don’t need to bother about relocating; all they need to do is be ready to grow directly after a fire.

They have a variety of modifications that enable them to do so.

1. They are capable of remaining dormant for long periods of time.
2. They live in cones that are sealed with a particular resin (glue) that only melts at the temperature of the fire, hot enough to kill adult trees to release the seeds.

Examples include lodgepole pine, eucalyptus, and banksia.

Seed Dispersal by Water:

Water is frequently used by plants that grow near or in water to distribute their seeds. These seeds are water-resistant and can have fluff or other features to help them float.

Coconuts, in particular, have waterproof wooden casings that allow them to be carried over great distances in saltwater. Coconut, palm, mangroves, water lily, and water mint are some examples of seed dispersal by water.

Seed Dispersal by Explosion

Some seeds distribute their seeds by practically exploding.

These dispersers’ seeds are contained in pods, which will eventually burst as the pod dries out, releasing seeds in all directions.

Witch hazel seeds are kept in tiny wooden capsules and can shoot several feet away when the pod bursts, which is a local example of this form of dispersal.