When we think of seasons, we often think of broad changes – the heat of summer, the cold of winter, the monsoon rains filling up the ponds and rivers, and the bloom of spring. What we rarely consider is that below the surface and in the depths, there are more subtle changes in the biological world.
Changes in the soil, the activation or deactivation of small organisms, the appearance and disappearance of temporary ponds, the shifting nature of a river bed, the release of fungal spores into the air, even the disruption of natural cycles by artificial lights in a city and the disruption of signals between various organisms.
Thus, seasonal biodiversity is not only about the changes that are readily seen in the biological world, but often about understanding how life functions with time.
I find the concept of seasonal biodiversity incredibly interesting because most of it takes place without us ever seeing it. Yes, we may see a dry patch of land, but below the surface there may be entire organisms that live in this dryness. We see a dark night turn to light with the coming of dawn, but for some creatures the artificial lighting could have sent an entirely different signal.
Thus, seasonal biodiversity is like a hidden book. We see the pages that are out on display, but the rest is written in the depths of the ground, the rivers and the darkness of the night.
The Biodiversity of the Soil
When we walk on soil, we rarely consider it to be anything other than dirt. However, soil is home to an incredibly diverse range of organisms, from bacteria to fungi to small animals. It is this range that makes the soil one of the most interesting places in terms of biodiversity.
The importance of this biodiversity has been noted by recent studies, that have found that biodiversity in the soil has a clear role in driving nutrient cycling, decomposition, plant productivity, and even climate regulation. Of particular interest are the fungi, that not only break down biological matter but form partnerships with plant roots, allowing them to absorb nutrients in a particular way. This directly affects carbon cycling in the soil, and can even indirectly impact the wider world.
What connects this to seasonal biodiversity is that the communities of soil organisms, while diverse, are rarely static. It has been found in a study on the Amazonian rainforest that the community structure of fungi, which drive many aspects of the soil biodiversity, was driven by different ecological processes depending on the season. This means that although the outside of the forest may not show large-scale changes, the hidden world of the soil has an entire seasonal cycle.
That kind of hidden cycle is part of seasonal biodiversity.
When a River Changes Into Something Else
When we think of a river, we often imagine a large body of flowing water. However, rivers are not always flowing – in fact, it has been estimated that over half of the world’s rivers cease to flow periodically. What is more, this cessation of flow does not simply impact the water, but the entire river ecosystem. While the flowing water hosts a variety of aquatic organisms, the now-stagnant riverbed can host a variety of microorganisms, plants, insects and other animals.
This creates an interesting anomaly in terms of biodiversity. The two types of communities – those found in flowing water and those found in stagnant water – are each unique and have their own characteristics. This seasonal change in biodiversity can be especially dramatic in rivers that only flow for a part of the year.
In a sense, a river can almost be two different ecosystems throughout the year.
This kind of change in biodiversity is also an aspect of seasonal biodiversity.
Temporary Ponds: Small Places, Big Biodiversity
Similar to stagnant rivers are the seasonal ponds and wetlands, that periodically dry up. The biodiversity of such places is heavily impacted by the phenomenon known as the hydroperiod, or the amount of time that water is present. Due to this, seasonal ponds and wetlands host a variety of different organisms, that have adapted to either take full advantage of the time that water is present, or to hibernate and awaken during the dry seasons.
This, similarly to the seasonal rivers, can result in dramatic changes to biodiversity. A pond that only exists for a few months may seem like an unimpressive sight to a passeranger, but ecologically it contains months of opportunity for the local biodiversity.
Another interesting aspect of seasonal ponds is that the changes in biodiversity throughout the year are driven not only by the changes in the water, but also by the light. Organisms have seasonal patterns of activity, reproduction, dormancy and feeding, that can be impacted by both the hydroperiod and the length of the day.
Thus, seasonal ponds and wetlands are a fascinating sight when it comes to seasonal biodiversity.
The Strange Effect of Artificial Night
There is one strange anomaly of seasonal biodiversity that is entirely artificial – the artificial night. When we think of the night, we often think of urban lights, as cities are filled with signs, lights on buildings and roads, parks and entertainment venues. What we rarely consider is how those artificial lights impact the world around us.
Biological organisms often rely on the natural cycle of day and night. The changes in temperature, light, humidity and other factors drive many seasonal patterns in the biosphere. Artificial lights, however, can disrupt some of those patterns by changing the amount or quality of light received by an organism.
This can be especially disruptive to nocturnal animals, that have to change their patterns of behaviour due to the artificial lights. The disruption has been observed in the case of fireflies and their ability to communicate with potential mates. The artificial lights have also been shown in research to disrupt some of the seasonal patterns in plants and animals.
Thus, the disruption of normal patterns due to artificial lights is another aspect of seasonal biodiversity that has been brought about by humans.
Fire Has a Season Too
When we think of fire, we rarely think of biodiversity. On the contrary, fire is often seen as an agent of destruction. However, when it comes to ecology, fire provides us with a prime example of seasonal biodiversity.
The reason for this is that in some biomes fire is an integral part of the local ecosystem. Many plants and animals have adapted to the presence of fire, and can thrive in biomes where it is a common occurrence. The key factor in this relationship is the timing – both plants and animals adapt to the particular fire season of an area. Fire has a particular frequency, duration, intensity and size, and an organism that lives in an area with particular statistics for those factors will adapt to them.
As a result, a change in any of those factors can impact fire-driven biodiversity. A study conducted recently has found, that outside the historical fire season, fire events can impact post-fire plant recruitment in some biomes in a negative way. The reason for this is that plants have seasonal patterns of reproduction and growth, and fire at an unexpected time can interfere with those patterns, causing disruptions to the wider ecosystem.
The timing of fire seasons, as well as fire events in general, is also being impacted by anthropogenic factors. Recent global research has found, that human activity has altered fire seasons in many areas of the world.
Thus, seasonal biodiversity has a vital lesson for us – that an organism’s ability to adapt to environmental change is often limited. While a forest may be able to withstand a fire, it may not be able to withstand a fire at an unexpected time.
Cities Have Their Own Seasons
When we think of biodiversity, we rarely think of cities. Urban areas are often seen as inhospitable to most forms of plant and animal life outside of pets and farm animals. However, it has been found that cities have their own unique patterns of seasonal biodiversity.
It has been discovered that large cities tend to be warmer than the surrounding areas, which is known as the urban heat island effect. A recent study reviewing urban heat islands in India has found that urban areas tend to have higher temperatures than the surrounding rural areas.
This can have a significant impact on local biodiversity, by altering temperature patterns. A plant growing in a city will experience a different set of temperatures than a plant of the same species growing outside the city. In addition, artificial lights can disrupt some elements of day/night rhythms.
Thus, it can be said that two similar places several kilometers apart can experience different sets of seasonal signals and clues.
This is why urban biodiversity should be studied and preserved as well, as the proper habitats can be created within cities and suburbs, providing suitable conditions for seasonal change. Parks, gardens, ponds, street vegetation and other man-made structures can provide the necessary habitats to support seasonal biodiversity in cities.
Fungi Have Their Own Calendar
There is one particularly fascinating element of seasonal biodiversity that is governed by fungi. When we think of the seasons, rarely do we consider fungi.
On the contrary, we tend to be surprised seeing mushrooms on a rainy day, or after a period of warm weather. What most of us fail to realise is that mushrooms are only a small part of the larger fungal ecosystem. Fungi tend to play important roles as decomposers, plant partners, and sometimes as pathogens.
The study of fungal biodiversity has been aided by recent research, that has taken swabs of the air, extracting DNA from it to build a profile of localised fungi. The findings of the study, published in Nature in 2024, show that there is a distinct pattern in the distribution and seasonal spread of fungi, with temperature being an important driver of those patterns.
What this means is that the air around us tends to have a variety of different fungi, depending on the time of the year.
Thus, the forest around us may not be as silent as we think – the air above it contains a number of biological clues for anyone willing to decipher them.
Why One Season Cannot Tell the Whole Story
One important insight that comes from studying the seasonal biodiversity is that any given observation can provide limited information. For example, if one were to visit a forest in January, the number of insects seen there could potentially impact the perceived biodiversity of the local area. If, months later, a researcher came back to the same forest and saw a vastly different number of insects, that would be an indicator of changing biodiversity.
The same applies to rivers, soil, ponds and urban areas. Seasonal biodiversity studies that span large time frames allow for the collection of data that would be unavailable to a researcher visiting the area only once.
This goes for conservation efforts as well. Understanding general patterns and timing in seasonal biodiversity can allow conservationists to better preserve the species in a given area.
For example, knowledge about the breeding seasons of different animals and plants allows conservationists to better monitor those species, understanding the delicate balance that keeps them in existence.
In other words, conservation needs its own calendar too.
## What We Can Learn From Seasonal Biodiversity
When it comes to the study of seasonal biodiversity, there is much to be learned.
First and foremost, the study teaches us to pay attention.
A dry river is not a dead river, a dark patch of soil is not barren, a winter garden is not empty, a mushroom appearing after rain is not an anomaly. All of these are signs of a far greater cycle, and each one is as important as the next.
This, among other things, points to the importance of understanding seasonal biodiversity. We tend to think of biodiversity in large-scale numbers and proportions, but it is crucial to realise that those numbers are only a small part of the equation. We cannot preserve a forest simply by counting species, for if their seasonal patterns change, they will soon disappear altogether.
Modern technology aids us in uncovering the mysteries of seasonal biodiversity. From DNA extraction to remote sensing and biodiversity monitoring, researchers can collect data about the biosphere, that would have taken centuries to compile otherwise.
Nevertheless, it is important to remember that everyone can participate in the study of seasonal biodiversity. Keeping a seasonal record of observations can be both enlightening and enjoyable. A student can keep a log of which plants bloom at what time of the year, and what insects appear with them. They can observe which birds arrive at a given area with the change of seasons, which ponds fill up with water, and which empty. After a year, those records can serve as an invaluable resource, providing insight into the local biodiversity of that area.
Conclusion: Nature Does Not Stand Still
Seasonal biodiversity teaches us that nature is not a still painting, but rather a dynamic narrative. Organisms do not simply exist – they thrive, reproduce, wither, die, and then begin anew. The changes are not always visible, as the seasons change the conditions underneath the surface of the earth, or the ebb and flow of a river. Temporarily existing ponds, fungi that follow a pattern of birth and death, fire that brings about a new cycle of life all teach us one simple lesson – biodiversity has a calendar.
If we protect our natural areas without taking into account seasonal biodiversity, we may fail to preserve the delicate patterns that constitute an ecosystem. A habitat may remain on the map, but the seasonal events that sustain it may be gone before long. That is why I believe that seasonal biodiversity deserves not only our attention, but our care. After all, the most fascinating thing about nature is not its biodiversity, but the patterns of how that biodiversity appears, disappears, sustains itself, and then reappears.
By: Rambabu yadav
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