Perennial plants are the most affected by climate change

Perennial plants are losing ground under the threat of climate change. As climatic conditions become more adverse, perennial plants try 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, those are perhaps the most important. Plants and animals have adapted to living in these cycles, using different rhythms according to their evolutionary adaptations.

Perennial and annual plants

Among plants, there are mainly two types of life cycles: annual and perennial. The two life cycles contrast each other and in some 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 diverse 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 is creating 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 most effective adaptations of the species to survive the difficult conditions of winter. When cold weather sets in, annual plants produce large numbers of seeds and then die.
Seeds are the most resistant organs of the plant, they can withstand very harsh climates and require only a little heat and humidity to germinate. This usually occurs in early spring.

After germination, annual plants will have a rush to develop in the spring. In a few months it will develop leaves and stems, flower, be pollinated and mature before the following fall.

Although their existence is short, they play a key role in the ecosystem, occupying ecological niches that other plant species cannot have. For example, an annual plant needs very little soil to grow; The roots are weak and underdeveloped but sufficient to absorb water and keep the plant with its light tissues during 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 important roles in the ecosystem. Although annual plants can germinate in rocky environments with very little soil, at the end of the year the plant will die and its body will be decomposed by microorganisms that will contribute to the formation of new soil and with it the beginnings of the formation of a more complex ecosystem. .

Classic examples of annuals include herbs, sunflowers, poppies, lettuce, peas and beans.

Defying the passage of time: perennial plants

If annuals are sprinters, perennials are natural marathoners. Annual plants have a lifespan of more than two years. More than two, because there are 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 so they can grow and flower many times. Their stems typically thicken and may become woody and form strong roots capable of reaching 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, but this process occurs at a slower rate because it requires more demanding conditions.

Once a small seedling is formed, the stem and roots begin to develop. Unlike annuals that seem to bloom quickly, perennials bloom longer and many do not bloom even in the first year because they spend most of their effort storing nutrients to survive the winter.

They are more competitive plants, they help maintain the structure of the soil and are largely responsible for maintaining the food web of ecosystems; They support biodiversity.

Examples of perennial plants are lavender, spearmint, mint; There are also tomatoes and peppers, although 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 disorders that disturb this balance. One of the greatest disturbances affecting all ecosystems on the planet is human-caused climate change.

According to a recent study published in the journal Nature, climate 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 perennials, especially in regions with warmer, arid temperatures.

This phenomenon has an evolutionary basis: the high adaptability of annual plants to harsh environmental conditions creates favorable conditions for colonizing new spaces, while perennial plants, characterized by a longer cycle and special growth needs, are more complex, which 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 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 for long periods of time. Although annual plants grow very quickly, they die quickly and their bodies decompose easily, quickly releasing captured carbon.

However, the storage organs of perennial plants function as long-term carbon storage. Replacing them with annual crops with lower biomass and shorter life cycles will reduce the ability of ecosystems to store carbon dioxide, worsening climate change. The landscapes may be greener, but they are much poorer and will be of little use.

Furthermore, replacing perennial plants with annual plants will change the regulation of water circulation in the ecosystem. Perennials, with their complex root systems, help maintain soil cohesion by allowing water to penetrate the soil. Its decrease will make the soil more susceptible to erosion, limit the replenishment of aquifers and increase drought and desertification.

Adopting and adapting conservation strategies to this new scenario is essential to minimize negative impacts on biodiversity and guarantee the resilience of ecosystems in the face of emerging environmental challenges. More research and monitoring is needed to better understand these changes and develop effective solutions to protect our natural heritage.

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