Adaptations plants had to make to be able to survive on land

Many years ago, plants made the drastic move from water onto land. Although at first they had a very difficult time surviving on land, they gradually became acclimated to their new terrestrial habitat. This was only after they had formed adaptations to overcome a slew of problems that plagued them on land. For example, they had needed an aquatic environment for both reproduction and to support the plant body, and they had to adapt to living without their aquatic surroundings. In addition, they now had to face the problem of dehydration. Fortunately, they were able to form adaptations to overcome all of these problems and today they successfully live and prosper on land.

Reproduction was an immediate issue because the plants could not carry out future generations without an aquatic environment for reproduction. They developed flowers, which have distinct and pleasurable shapes, colors, smells, chemicals, and nectar to attract insects and birds, which help in pollination. Males developed microspores, which is pollen, and a reduced gametophytes. The pollen grain became very light weighted and easily blown about in order to increase motility. It is now possible for pollination to occur by wind, insects. In fact, many plants can even self-pollinate.

The female also developed a reduced gametophytes, in the megaspore or the mega sporangium. Nature had to evolve protection for the gametophytes, and it came up with an embryo inside the ovary, carpel, or pistil. The seed also evolved a hardened protective covering to aid in reproduction. Seed became carried in fruits, which were eaten by animals that dispersed the seeds and aided in reproduction. In addition, seed dormancy allows the seed to remain latent for extended periods of time. Lastly, the evolution of internal fertilization using the pollen tube and endosperm helped plants overcome the lack of aquatic environment for reproduction.

Plants were accustomed to the aquatic environment supporting them, but as they begin to live on land they no longer had this luxury. They had to develop a strong stem for support and a root system for anchorage and also for water absorption. They also had to develop vascular tissue, including xylem fibers, tracheids, vessels, heartwood, dead tissues, and phloem. This allowed for a strong support and also for water to be distributed within the plant. A strong cell wall was developed, which was hardened with lignin and contained cellulose to provide cell wall support. A secondary thickening, cambium, was developed to aid this support. In addition, other forms of support, such as vines and tendrils developed ito provide supplementary support to many plants. Schlerenchyma and collenchyma cells developed to provide further support, and buttressed roots kept plants standing firmer than ever.

As plants began living on land and were no longer in water, dehydration became a major problem. Fortunately, plants were able to develop adaptations to help them deal with this issue. Firstly, they developed tiny root hairs to maximize surface area and therefore maximize absorption to keep as much water as possible in the system. They also developed a waxy cuticle in order to keep water loss to a minimum. They developed a virtually impermeable bark with suberin and cork to keep in water, and they developed scales to protect buds and sepals and petals to protect floral parts. They developed stomata, which are controlled by guard cells, in order to control water movement and regulate transpiration. Xylem developed in order to transport water throughout the plant. In addition, other leaf, stem, and root modifications occurred in order to minimize water loss. There is significant surface area reduction and small or no leaves in desert plants which have very limited access to water. The cortex is able to store and retain water, which helps conserve it inside the plant. CAM and C4 plants have modified stomata functions in order to undergo photosynthesis with very little water loss.

Many years ago, plants made the drastic move from water onto land. Although at first they had a very difficult time surviving on land, they gradually became acclimated to their new terrestrial habitat. This was only after they had formed adaptations to overcome a slew of problems that plagued them on land. They had needed an aquatic environment for both reproduction and to support the plant body, and they had to adapt to living without their aquatic surroundings. In addition, they now had to face the problem of dehydration. Fortunately, they were able to form adaptations to overcome all of these problems and today they successfully live and prosper on land.