The technique by which plant seeds are moved to new locations for germination and the creation of new individuals is known as seed dispersion. Animals frequently mediate this process, and as a result, the final destiny of seeds is determined by their ability to disseminate seeds. Dispersed seeds, in turn, have an impact on the dynamics and genetic structure of plant populations, as well as the long-term survival of communities. Many studies have attempted to unravel the complicated processes that occur between the creation of a seed and the establishment of a new plant as a result of these repercussions. Given the need to predict how populations will respond to habitat fragmentation and climate change, as well as the invasion and spread of alien species, an understanding of the ecological and evolutionary consequences derived from the intimate link between animal behaviour and seed dispersal is critical.
Seed dispersal:
The movement, dispersion, or transfer of seeds away from the parent plant is referred to as seed dispersal. Water is used by many plants to disperse their seeds. The seeds separate from the parent plant and float away.
Seed dispersal methods :
Plants produce seeds that can germinate and grow into new plants, but if the seeds fall to the ground under the parent plant, they may not receive enough sunlight, water, or nutrients from the soil. Plants have devised various techniques to distribute (transport) their seeds because they can’t walk about and carry them with them. The most common ways are as follows:
Dispersion by wind:
Have you ever blown on the crown of a dandelion and seen the seeds drift away? This is the process of wind dispersal. Seeds from dandelions, swan plants, and cottonwood trees are light and bristly, allowing them to be distributed over long distances by the wind. Some plants, such as kauri and maple trees, contain ‘winged’ seeds. Rather than gliding away, they flutter to the earth. Rather than gliding away, they flutter to the earth. The seeds are simply blown around by the wind and settle in a variety of locations. These plants must generate a large number of seeds in order to increase their chances of at least part of the seeds landing in a favourable location for growth.
Water dispersal:
Water is used by many plants to disperse their seeds. The seeds separate from the parent plant and float away. Estuaries are home to mangrove trees. A mangrove seed might begin to root in the soil if it falls during low tide. If the seeds fall into the sea, the tide will carry them away to sprout somewhere. Water dispersion is also used by kowhai trees. They have a tough seed covering that enables them to float down rivers and streams. One of the reasons kowhai trees are so widespread along stream banks is because of this.
Animal dispersal:
In New Zealand’s woody woods, almost 70% of the plants contain fleshy fruit that birds consume. Chemicals in the digestive tracts of our native birds assist to break the thick coverings that surround these seeds. Birds like the kerer, sparrow, and bellbird play a vital part in seed dispersal by flying far away from the parent plant and dispersing the seeds in their droppings. Because the kerer has such a broad, wide beak, the trees that produce the largest fruit – miro, priri, tawa, and taraire – rely on it to consume the fruit. Some seeds feature hooks or barbs that grab on the hair, feathers, or skin of an animal. Birds can carry away plants with sticky seeds, such as pittosporum. Seeds may also be distributed by humans if they stick to our clothing or shoes, as well as if we throw fruit pips and stones out the vehicle window.
Explosions:
This technique of seed dissemination isn’t as thrilling as it may appear. Seedpods of some plants, such as peas, gorse, and flax, dry out after the seeds are ready. When the pods are dry, they break open and the seeds fall out. If you’re lucky, you’ll hear the gorse seed pods popping out on a hot summer day as you stroll past a gorse bush.
Fire:
Because plants cannot escape a fire, some have evolved a strategy to assist their seeds survive. Some pine tree species require the heat of a fire to open their cones and release seeds. Fire is also used by banksias, eucalypts, and other Australian plants. The fire’s strength and timing are crucial. It must be hot enough to cause the cones to open, but if fires occur too often, the plants will not have enough time to grow large enough to produce new seeds.
Seed dispersal benefits:
Seed dispersion has the following advantages:
- i) It minimises overpopulation of plants in a given region.
- ii) Seed dispersion prevents plants of the same species from competing for water, nutrients, and sunshine.
iii) Seed dispersal allows plants to spread farther by allowing them to develop in new locations (or habitats).
Conclusion:
Seeds can be disseminated in a variety of methods. We’ve learnt how to start the development of new plants in a variety of methods. Seeds are critical to our planet’s survival. Seeds have evolved organically to give the optimum possibility for producing additional plants without the assistance of humans.