Perennial plants are losing ground due to climate change. As climatic conditions become increasingly harsh, perennial plants are trying to resist and fight for their place in nature.
The life of living organisms is organized in successive cycles: day and night, the seasons and, in coastal areas, the tides, these are perhaps the most important. Plants and animals have adapted to living in these cycles and use different rhythms depending on their evolutionary adaptations.
Perennial and annual plants
There are mainly two types of life cycles in plants: annual and perennial. The two life cycles are in contrast to each other and in a certain way determine the rhythm of the ecosystem. While annual plants complete their life cycle in less than a year, perennial plants persist despite the passage of time.
These dynamics support complex ecological networks and reflect adaptation to different environments. There is a reason why plants are the foundation of terrestrial ecosystems. Perennial and annual plants perform different functions in the environment and their populations are maintained in the balance necessary for the normal functioning of the ecosystem. However, human-caused climate change creates new challenges by disrupting this balance.
Annual plants: They complete their life cycle in a few months
The annual life cycle is one of the species’ most effective adaptations to survive the difficult conditions of winter. When cold weather sets in, annual plants produce large quantities of seeds and then die.
Seeds are the most resilient organs of the plant, they can withstand very harsh climates and require little heat and moisture to germinate. This usually happens in early spring.
After germination, the annual plants develop rapidly in spring. In a few months it develops leaves and stems, flowers, is pollinated and matures before the next fall.
Although their existence is short-lived, they play a key role in the ecosystem and occupy ecological niches that other plant species cannot. For example, an annual plant requires very little soil to grow; The roots are weak and underdeveloped, but sufficient to absorb water and support the plant with its light tissue throughout its short life. Its accelerated life cycle allows it to respond quickly to environmental opportunities such as short-term water abundance or temporary deforestation.
They also play an important role in the ecosystem. Although annual plants can germinate in rocky environments with very little soil, at the end of the year the plant dies and its body is decomposed by microorganisms that contribute to the formation of new soil and thus the beginnings of the formation of a more complex ecosystem. .
Classic examples of annual plants are herbs, sunflowers, poppies, lettuce, peas and beans.
Defying the passage of time: perennial plants
While annual plants are sprinters, perennial plants are natural marathon runners. Annual plants have a lifespan of more than two years. More than two because there are only a few: biennial plants that complete their life cycle in exactly two years; The first develops stems, leaves and roots, the second develops flowers, fruits and seeds.
Perennial plants have a long life cycle, allowing them to grow and bloom many times. Their stems typically grow thicker and can become woody, forming strong roots that can reach deeper sources of water and nutrients.
They also have tissues that store nutrients in their roots or stems, sometimes underground, called rhizomes. The life cycle of perennials also begins with seed germination, although this process is slower because it requires more demanding conditions.
Once a small seedling is formed, the trunk and roots begin to develop. Unlike annual plants that seem to bloom quickly, perennial plants bloom longer and many don’t even bloom in the first year because they spend most of their energy storing nutrients to survive the winter.
They are more competitive plants, help maintain soil structure and are largely responsible for maintaining the food web of ecosystems. They support biodiversity.
Examples of perennial plants include lavender, spearmint, peppermint; There are also tomatoes and peppers, but they are grown and harvested annually in the garden.
Climate change favors annual plants
Stable ecosystems are largely due to the balance between annual and perennial plant populations. Each type fulfills its function, although sometimes there are disturbances that upset this balance. One of the biggest disruptions affecting all ecosystems on the planet is human-caused climate change.
According to a recent study published in the journal NatureClimate change is causing significant changes in the global distribution of annual and perennial plants. This study shows that changing climate conditions favor annual plants over perennial plants, particularly in regions with warmer, drier temperatures.
This phenomenon has an evolutionary basis: the high adaptability of annual plants to harsh environmental conditions creates favorable conditions for the colonization of new spaces, while perennial plants, characterized by a longer cycle and special growth needs, are more complex, which makes it difficult to adapt to changing climatic conditions .
Importance for ecosystems and biodiversity
This imbalance could have serious consequences for the global ecosystem at all levels. As already mentioned, annual plants support the biodiversity of the ecosystem.
Longer flowering periods help maintain pollinator populations year-round. Higher biomass productivity provides more food for herbivores. In general, its presence ensures the stability of the food web and its collapse could destabilize these processes.
Perennial plants, on the other hand, are important for their ability to capture and store carbon over long periods of time. Although annual plants grow very quickly, they die quickly and their bodies decompose easily, quickly releasing trapped carbon.
However, the storage organs of perennial plants act as long-term carbon stores. Replacing them with annual crops with lower biomass and shorter life cycles reduces the ability of ecosystems to store carbon dioxide, worsening climate change. The landscapes are greener, but much poorer and of little use.
In addition, replacing perennial plants with annual plants will change the regulation of water circulation in the ecosystem. With their complex root systems, perennials help maintain soil cohesion by allowing water to penetrate the soil. Its decline will make soil more vulnerable to erosion, limit aquifer recharge, and increase drought and desertification.
Adopting and adapting conservation strategies to this new scenario is essential to minimize negative impacts on biodiversity and ensure ecosystem resilience in the face of emerging environmental challenges. Further research and monitoring is needed to better understand these changes and develop effective solutions to protect our natural heritage.
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