The classic four seasons no longer exist in the world, scientists say

For their research, scientists analyzed satellite monitoring data over 20 years, which tracked the reflection of infrared light by vegetation throughout the year. This allowed them to create a unique and detailed map of seasonal growth rhythms of plants around the world, enabling a new perspective on the "natural calendar."

Main findings: the absence of universal seasons

The results of the study challenge the widely accepted model of four seasons.

Diversity instead of uniformity: The research showed that even neighboring regions can vary significantly in the timing of key natural events, such as the beginning and end of the growing season. A striking example is mountainous areas in the tropics or regions with a Mediterranean climate, where seasonal asynchrony occurs over short distances.

Dynamics of factors: In high latitudes, for example, in most areas of Europe and North America, temperature conditions remain key for plant growth. However, in arid and tropical ecosystems, the availability of light and water is much more important than average temperature indicators.

Impact on biodiversity and economy: These differences in seasonal niches can contribute to high levels of biodiversity, especially in tropical regions. Temporal separation of reproduction can lead to the formation of new species. For instance, such a map helps explain the complex geographical features of coffee harvesting seasons in Colombia, where farms located just a few hours apart can have unsynchronized reproductive cycles, as if they were in different hemispheres.

Researchers' opinion

"Seasonality is often perceived as a simple rhythm — winter, spring, summer, fall, but our work shows that the natural calendar is much more complex," comments Drew Terasaki Hart. She emphasizes that this is particularly noticeable in areas where the shape and timing of the local seasonal cycle vary greatly depending on the landscape. "This can have serious implications for ecology and evolution in these places."

This study is not an isolated case. It resonates with the work of other scientists who point out that anthropogenic impact and climate change not only shift seasons but also create new phenomena, such as the "haze season" in Southeast Asia and the "garbage season" in Bali. Furthermore, it aligns with the fact that many cultures historically used more fragmented calendar systems, for example, dividing the year into 24 seasons or 72 micro-times, to more accurately describe changes in nature.

Thus, the research by the CSIRO team represents a new and more detailed tool for understanding life on Earth. This map of seasonal rhythms opens new horizons not only for fundamental science in ecology and evolutionary biology but also for practical fields such as agriculture, forestry, and epidemiology. The study reminds us that nature does not operate according to simplified patterns, but according to complex and variable laws that we are just beginning to comprehend.