For every plant that disappears, another plant may newly arrive. Climate change is not only a force that empties ecosystems, but also a force that reshapes where life can exist and how living things relate to one another. The problem is that even when the number of plant species in a region appears to increase, this does not mean that the global loss of biodiversity is being prevented.

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When climate change and biodiversity are discussed, the first image that usually comes to mind is fairly familiar. Temperatures rise, rainfall patterns change, droughts and heat waves become more frequent, and living things gradually lose the places where they have long survived. Forests dry out, coral reefs turn white, Arctic ice shrinks, and wild animals can no longer keep pace with the seasonal rhythms they once knew. This explanation is not wrong. Climate change has already become one of the greatest survival pressures for many forms of life, and it is acting as a major driver accelerating the decline of biodiversity.

But nature cannot always be explained as a simple change moving in only one direction. While some living things disappear, others newly arrive. While one region’s habitat becomes no longer suitable, another region becomes newly suitable. Plants tied to cold climates move farther north, plants that once lived at lower elevations move up into higher mountains, and when rainfall increases in formerly dry regions, plants that previously struggled to establish themselves may begin to take root. Climate change is a force that reduces nature, but at the same time, it is also a force that redraws nature’s map.

In May 2026, a study published in Science by researchers including Junna Wang, Bruno F. Oliveira, Frances C. Moore, Daniel J. K. Karger, Fu Yongshuo, and Dong Xiaoli analyzed the future habitat changes of more than 60,000 plant species and showed that climate change does not simply reduce plant diversity, but instead drives a complex process of reorganization in which species inflows and losses occur simultaneously across different regions. It is often said that climate change reduces biodiversity, but in actual ecosystems, plant species may decline in some regions, increase in others, and in still others the total number of species may remain similar while the composition itself changes completely.

This point is important. Biodiversity is not simply a matter of numbers. It is important to know how many plant species exist in a given region, but it is equally important to examine which plants are disappearing, which plants are arriving, and how those changes affect soil, insects, animals, and human life. Even if the number of plant species appears to increase on the surface, if long-standing endemic species disappear in the process and are replaced by widespread generalist species, the ecological meaning becomes entirely different. The number may rise, but uniqueness may decline.

Nature in the age of climate change is being emptied and filled at the same time. In some forests, existing plants disappear, and other plants take their place. In some grasslands, plants that were not there in the past appear, and in some mountain regions, plants from lower elevations move upward. At first glance, these changes may look like abundance. But that abundance may not be a sign of stability; it may be a signal that the ecosystem is being shaken. The arrival of new plants may represent nature’s recovery, but it may also be the result of the collapse of an existing order.

To understand how climate change affects plant diversity, the first question to ask is “What scale are we using as the standard?” A village forest, a mountain ridge, a country’s flora, and the biodiversity of the entire planet are all different units of observation. At the local level, the number of species may increase as new plants arrive. But when the view is widened to the entire planet, that increase is not necessarily good news. A plant newly found in one region may be a plant that has been pushed out of another region, and while some species find places to move to, others may eventually have nowhere left to go.

One of the most common illusions in ecological change comes from mistaking local numbers for the health of the whole. If we look only at the fact that plant species have increased in one region, climate change may seem not entirely bad. In fact, warmer temperatures or increased rainfall may make it possible for new plants to establish themselves in some regions. But this phenomenon does not mean that climate change is easing the biodiversity crisis. Rather, it may mean that living things are being pushed out of their original habitats.

Plant movement is far slower and more complex than animal movement. Birds and mammals can move their bodies and relocate their habitats relatively quickly. Plants, however, cannot walk away once they have put down roots. Their seeds spread on the wind, travel along waterways, move on the bodies of birds or mammals, and sometimes disperse through human movement and agricultural activity. Movement occurs slowly, across generations. The problem is that the pace of climate change may be faster than this natural pace of movement.

Nor does the arrival of a seed in a new place guarantee successful establishment. Plants need more than the right temperature. Rainfall, soil acidity, nutrients, sunlight, competition with nearby plants, insects, microorganisms, and pollinators that carry pollen all have to align. Suitable climate conditions alone do not complete the full set of survival conditions. A plant’s habitat is not merely a space, but an ecological position formed by many overlapping relationships.

That is why plant migration caused by climate change becomes an opportunity for some species, but not an escape route for all species. Plants that can live across broad regions and adapt to various environments are more likely to find new habitats. By contrast, plants that depend on specific mountains, islands, coastlines, wetlands, or soils have a much harder time moving. Plants living on mountaintops have nowhere higher to go, island plants must cross the sea, and plants that grow only in certain soils may be unable to take root elsewhere even if the climate is suitable.

An increase in local diversity therefore carries a double meaning. On the one hand, it is a signal that nature is responding to change. Living things do not simply wait passively for extinction. They move where they can, adapt to new conditions, and form new relationships. On the other hand, however, it is also a signal that existing ecosystems are being destabilized. If an increase in one region is connected to a decline in another region, then that increase is not a recovery of overall biodiversity, but merely a redistribution.

One frequently discussed solution in debates about biodiversity in the age of climate change is helping living things move. This includes connecting forests to other forests, creating ecological corridors between protected areas, and reconnecting habitats that have been fragmented by roads or urban development. Such approaches are important. When the climate changes, living things must move in search of new climate conditions, and if their routes are blocked, extinction risks rise.

But movement alone does not solve every problem. The larger problem arises when there is no longer any place to move to. As temperatures rise and rainfall patterns change, the climate space suitable for certain plants may shrink overall. Areas that were once broadly suitable may become fragmented into isolated patches in the future, or disappear altogether. In such cases, movement is not enough. Even if there is a route to travel, survival cannot be guaranteed if there is no place to arrive.

This problem becomes more serious as climate change intensifies. If greenhouse gas emissions continue to rise and the scale of warming increases, plants will be required to move faster and farther. But there are limits to how quickly plants can move. Seeds must disperse, germinate, grow, and produce seeds again, all of which takes time. This is especially true for trees with long generations and slow growth. For forest-forming trees to move along with shifting climate zones, decades or even centuries may be required.

Human-made barriers add another layer of difficulty. Farmland, cities, roads, industrial complexes, dams, mines, and pastures cut off the pathways along which plants might move. Forests and grasslands that were once naturally connected become fragmented, and plants lose places to establish themselves in between, even if they are moving toward a suitable climate. When climate change and land-use change combine, plants face a double pressure. Climate pushes them out on one side, while humans block their path on the other.

For this reason, plant conservation cannot end with predicting future climate maps. It must also examine whether plants can actually move, whether they can survive after moving, and whether they can maintain ecosystem functions in new regions. A climate-suitable area may exist on a map, but if that place has already become a city or farmland, or if it does not have the necessary ecological conditions, it cannot serve as a real refuge for plants.

Climate change alters the distribution of living things while also reducing the area in which they can survive. This is the core of the discussion. Movement may help maintain or increase plant diversity in some regions, but it does not greatly reduce the risk of global extinction. Some plants expand into new regions, while others lose the overall area in which they can live. If we look only at successful examples of movement, it may seem that nature is adapting, but behind those cases are plants quietly disappearing.

One of the most fascinating and uncertain scenes created by climate change is the emergence of new plant communities. Plants that did not live together in the past are beginning to meet in the same regions. Plants from the south move into areas that have become warmer, plants that prefer wetter conditions enter regions where rainfall has changed, and plants that spread rapidly along with human activity compete with existing species. The plant combinations formed in this way are different from the forests or grasslands of the past.

Ecosystems are the result of relationships formed over long periods of time. Some plants provide food for certain insects, and some insects carry pollen for certain flowers. Some trees provide nesting places for particular birds, and some grasses regulate the flow of moisture and nutrients in the soil. When plants change, insects change, and when insects change, birds and mammals change as well. Plants are not the background of an ecosystem; they are the foundation that makes the ecosystem function.

When new plant communities form, the rhythm of the ecosystem changes as well. The timing of flowering, leafing, fruiting, and leaf fall changes. The problem is that this rhythm must align with the life cycles of other organisms. If flowers bloom but the insects that carry their pollen have not yet emerged, or if fruit appears but no longer matches the migration timing of the birds that eat it, ecological connections weaken. Plant movement is not merely a change in location; it is also a change in timing.

Newly arriving plants are not necessarily bad. Some plants can stabilize soil, store carbon, and provide new food sources for animals in changed environments. In regions where the climate has already shifted, newly arriving plants may sometimes stabilize ecosystem functions better than plants from the past. Nature is not a fixed museum, and ecosystems have always changed. The important task is not to block all change simply because it is change, but to judge which changes damage ecosystem function and uniqueness.

But new combinations also carry risks. Some plants may quickly push out existing species, intensify competition for water and nutrients, help pests and diseases spread, and increase wildfire risk. In particular, ecosystems already stressed by climate change may be more strongly affected by incoming species. If new plants spread rapidly while existing plants are weakened, the balance of a local ecosystem can change dramatically in a short period of time.

These changes also have direct effects on humans. Plants hold soil in place, store water, absorb carbon, and provide the foundation for agriculture and forestry. Medicinal plants, wild relatives of food crops, timber resources, and sources of fiber, dyes, and fragrances all depend on plant diversity. When the plant composition of a region changes, it is not only the landscape that changes. Water management, wildfire risk, agricultural productivity, local culture, ecotourism, and the possibility of disease spread may all change as well.

The emergence of new plant communities is therefore not merely an academic matter. It is a question about what kind of nature humans will live within in the future. Future forests may differ from today’s forests. Future fields may be filled with plants different from those we see today. Climate change does not merely alter the outward appearance of nature; it also changes the ways nature has provided functions and benefits to human society.

Plants are often regarded as static beings. They do not run, fly, or swim like animals. But plants move, too. Their movement, however, takes place through the language of seeds and generations. Seeds carried by the wind, seeds that pass through the bodies of birds and travel long distances, seeds carried downstream by rivers, and seeds that cling to animal fur are all ways in which plants move. A forest may appear still, but seen through the long lens of time, it is a slow-moving flow of life.

The problem is that climate change is compressing this long order of time. In the past, climate changes often unfolded over thousands or tens of thousands of years. Plants could gradually alter their distribution across generations. Today’s human-driven climate change, however, is progressing very rapidly. Greenhouse gases accumulated since industrialization are raising the global average temperature, and extreme weather is becoming more frequent and more intense. The time available for plants to adapt is shrinking.

This difference in speed places great pressure on ecosystems. Fast-reproducing grasses and weedy plants can respond relatively quickly to change. By contrast, long-lived trees, rare plants that grow only in specific environments, and plants with long reproductive cycles struggle to keep up. If the trees that form the core of a forest cannot move in line with the climate, the structure of the entire forest may be shaken. When trees disappear, shade, humidity, soil, insects, and bird habitats all change together.

The slow movement of plants also has major implications for conservation strategy. Simply designating protected areas and preserving the plants currently within them may no longer be sufficient. There is no guarantee that today’s protected areas will maintain suitable climates for those same plants in the future. Today’s protected area may become tomorrow’s climate-risk zone. Conversely, regions that do not currently receive much attention may become important climate refuges in the future.

That is why future biodiversity conservation must also address the question of time. It must examine not only which plants are where today, but also where they may be able to survive 30, 50, or 100 years from now. Protected areas must become connected networks rather than fixed points, and corridors and buffer zones that take plant movement into account are needed. Paths along which seeds can spread, forests can connect, and rivers and mountain systems can link together must be secured.

Of course, ways for humans to directly assist plant movement may also be discussed. This can include moving the seeds of plants at high risk of extinction into areas expected to be suitable in the future, or using botanical gardens and seed banks to preserve genetic diversity. But such approaches must be used carefully. Poorly planned movement can disturb ecosystems in new regions and create unexpected problems of competition and disease. Moving plants is not a simple rescue operation; it is an intervention in the relationships of an entire ecosystem.

Conservation in the age of climate change is therefore more difficult. In the past, the focus was largely on preventing things from disappearing. Now, in a changing natural world, it is necessary to decide what must be protected and what changes must be accepted. It is becoming increasingly difficult to preserve nature exactly as it was in the past. But that does not mean every change can be accepted as natural adaptation. The disappearance of endemic species, the collapse of habitats, and the weakening of ecosystem functions are clearly losses.

Biodiversity is often expressed in terms of the number of species. How many species live in a region, how many plant species exist in a forest, and how many endemic species a country has are important indicators that show the state of an ecosystem. But numbers alone are not enough. Even if there are 100 species in both cases, the ecological meaning differs completely depending on which 100 species they are.

For example, suppose that 100 plant species originally lived in a region, and that 100 species still remain after climate change. On the surface, it may look as if nothing has changed. But if 30 endemic plant species disappeared and were replaced by 30 species commonly found in other regions, the story is different. The number of species is the same, but the uniqueness of the region has declined. The ecological characteristics and evolutionary history that could be found only in that region have disappeared.

Another case is also possible. The number of plant species may increase from 100 to 120. Looking only at the number, diversity has increased. But if the 20 newly arriving species compete strongly with existing plants, change soil properties, increase water use, and raise wildfire risk, that increase cannot easily be called healthy diversity. The quantity of diversity and the quality of diversity can be different.

Biodiversity includes uniqueness, function, relationships, and resilience. Uniqueness is the history of life found only in a particular region. Function is the role plants play in storing carbon, protecting soil, and supporting food webs. Relationships are the connections between plants, insects, microorganisms, animals, and humans. Resilience is the ability of an ecosystem to regain balance after shocks such as drought, heat waves, pests, disease, and wildfire. An increase in the number of species does not mean that all of these elements improve together.

Climate change, in particular, can lead to the homogenization of ecosystems. Unique plants from diverse regions may disappear, while plants with strong adaptability and wide dispersal ability may appear commonly across many regions. In that case, the number of plant species in each region may be maintained or even increased, but the ecological distinctiveness of the planet as a whole declines. A world in which similar plants appear everywhere may look rich in numbers, but in reality it may be a poorer natural world.

This issue is connected to culture as well. Plants are not merely biological beings. They are connected to local landscapes, foods, medicines, rituals, languages, and memories. Some trees are symbols of a region, some flowers create the feeling of a season, and some herbs are linked to long-standing practical wisdom. When such plants disappear due to climate change, the loss of nature becomes a loss of culture. The decline of biodiversity is also a change in the way humans remember and perceive the world.

For this reason, the statement that climate change does not necessarily reduce plant diversity in every case must be read very carefully. It does not mean that climate change is safe. Rather, it means that changes in biodiversity are far more complex than numbers alone can show. Local increases, global losses, the weakening of uniqueness, and changes in ecosystem function can occur at the same time. Nature is not simply shrinking; it is being reassembled in unfamiliar ways.

If climate change is transforming plant distributions and local diversity in complex ways, conservation strategies must change as well. In the past, conservation mainly involved protecting specific areas and preserving the species within them. National parks, nature reserves, wetland protection areas, and forest reserves are representative tools of this approach. Such methods remain important. If habitat destruction is not stopped, no climate adaptation strategy can work properly.

But in the age of climate change, protected areas alone are not enough. When climate zones move, the places that living things need also move. Today’s protected areas may not be tomorrow’s refuges, and regions that are not protected today may become important habitats in the future. Conservation must therefore go beyond fixed maps and consider future climate maps as well. Places to protect should be chosen not only according to their current value, but also according to their future potential.

First, it is important to identify and protect climate refuges. Climate refuges are areas where change is relatively moderate compared with surrounding regions, or where various microclimates allow living things to survive. Deep valleys, north-facing slopes, humid forests, mountains with large elevation differences, and wetlands influenced by groundwater may serve as refuges for some plants. Such areas can become key spaces that support biodiversity in the midst of climate change.

Second, connectivity is important. For plants to move, habitats must be connected. If protected areas are isolated like islands, living things find it difficult to move in response to climate change. Ecological networks that connect forests to forests, wetlands to wetlands, and mountains to rivers are needed. Even between cities and farmland, green corridors and buffer zones can be created to help living things move. Connected nature is stronger in the face of change than fragmented nature.

Third, the roles of seed banks and botanical gardens are growing. Not all plants can be protected only in the field. Plants whose habitats are rapidly shrinking, plants with nowhere to move, and plants whose populations are too small must have their seeds and genetic resources preserved separately. Seed banks are like insurance that leaves open the possibility of future restoration. Botanical gardens can serve not merely as exhibition spaces, but as living repositories that preserve and study the genetic diversity of endangered plants.

Fourth, conservation priorities must be established more precisely. Not all plants can be protected in the same way. Widely distributed plants and plants found only in narrow regions, fast-reproducing plants and slow-growing plants, plants that play core roles in ecosystem function and plants with great cultural value all require different strategies. Endemic species and plants dependent on narrow habitats that are vulnerable to climate change require especially careful protection.

Fifth, we must not forget that reducing greenhouse gas emissions is the most fundamental conservation strategy. Helping plants move, expanding protected areas, and strengthening seed banks are all important. But if the speed and scale of climate change continue to grow, these efforts will reach their limits. The most fundamental way to protect biodiversity is to slow climate change itself. Buying nature time to adapt is the most important form of conservation.

Changes in plant diversity are not a problem for nature alone. Human society depends deeply on plants. Food, timber, fiber, medicine, fuel, paper, spices, rubber, dyes, landscaping, spaces for rest, carbon absorption, water circulation, and soil protection all come from plants. Plants are not the background of human civilization; they are the foundation of human life.

When the distribution of plants changes due to climate change, agriculture is affected as well. Crops themselves are plants, but the wild plants surrounding crops are also important. Wild plants provide habitat for pollinating insects, support natural enemies of pests, and influence soil health. If plant diversity declines or its composition changes, the stability of agricultural ecosystems also changes. The disappearance of certain plants in a region can ultimately be connected to food production.

There is also the issue of medicinal plants. Many medicines and health resources used by humans began with plants. Many plants have not yet been studied, and some ways of using plants remain only within the traditional knowledge of particular regions. When plants disappear because of climate change, it is not merely one biological species that disappears; future medical possibilities and local knowledge assets may disappear with it.

Changes in forests are also connected to the carbon cycle. Through photosynthesis, plants absorb carbon dioxide from the atmosphere and store carbon in trees and soil. If climate change weakens plant growth or reduces forests, their ability to absorb carbon may decline as well. This can create a feedback loop that worsens climate change. If plants weaken, climate change intensifies; if climate change intensifies, plants face even greater pressure. A vicious cycle can emerge.

Water management is also deeply connected to plants. Forests and grasslands hold rainwater, reduce soil erosion, and regulate the flow of rivers. When plant composition changes, the capacity to retain water, transpiration, and soil stability also change. Depending on which plants increase, vulnerability to drought or flood risk may also change. Changes in plant diversity may not be immediately visible, but they alter the basic conditions of life: water and soil.

Cities are no exception. Urban green spaces ease heat waves, reduce fine dust, and provide people with rest and psychological stability. As climate change intensifies, the question of which trees to plant and which plants to conserve in cities becomes more important. Street trees that grew well in the past may not endure future heat and drought, and newly introduced plants may have unexpected effects on urban ecosystems. Plant selection in cities is not a matter of appearance, but a matter of climate adaptation.

In the end, changes in plant diversity are not a concern only for nature conservation experts. Farmers, forestry workers, urban planners, health experts, companies, governments, and citizens are all affected. When plants change, landscapes change, and when landscapes change, life changes. Plant migration in the age of climate change is not a quiet event hidden in the forest, but an event that changes the future conditions of human society.

The idea that climate change does not necessarily reduce plant diversity in every case can easily be misunderstood. Some people may take it as evidence that climate change is less serious than expected. If plant species increase in some regions, they may think nature is adapting on its own. But this is a dangerous interpretation. A local increase does not erase global risk.

At the same time, it is also insufficient to see every change only as a disaster. In actual nature, inflows and losses happen simultaneously. Living things respond to new conditions, some plants expand, and some regions may come to have richer floras. The effects of climate change differ by region, by species, and over time. This complexity must be understood in order to respond more realistically.

What is needed between optimism and pessimism is accurate understanding. We must examine where, why, and around which species increases in local plant diversity occur. We must determine whether such increases strengthen ecosystem function or merely hide the loss of existing endemic species. We must also examine what relationships newly arriving plants create, what competition they engage in with existing plants, and how they affect insects and animals.

Biodiversity in the age of climate change cannot be summarized in a simple profit-and-loss statement. Some regions gain, and others lose. Some species expand, and others disappear. Some ecosystems are newly assembled, and others lose resilience. The reality of climate change is that gains on one side and losses on another occur at the same time.

This complexity also sends an important message to policy. Biodiversity conservation cannot rely only on expanding protected areas or managing species counts. It must read the direction of change in each region in detail, prioritize endemic and vulnerable species, and establish long-term strategies that consider future climate conditions. More refined judgment is needed between the attitude of trying to freeze nature in its past form and the attitude of allowing every change to proceed unchecked.

Above all, climate change response and biodiversity conservation cannot be separated. If greenhouse gas emissions are not reduced, the time and space plants need will continue to shrink. If habitats are not protected, plants will lose pathways for movement. If genetic diversity is not conserved, the possibility of adaptation will also decline. Climate policy, land policy, agricultural policy, forest policy, and urban policy must move together.

Perhaps the most important sentence for understanding plant diversity in the age of climate change is this: nature is shrinking and being reorganized at the same time. Some plants disappear, and others arrive. Some regions are emptied, and others are filled. Some ecosystems become simpler, and others become more complex through unfamiliar combinations. Change is not moving in one direction, but in several directions at once.

But this complexity does not reduce the seriousness of the climate crisis. Rather, it means that more careful observation is needed. If we look only at whether the number of plant species has increased or decreased, we may miss important changes. Even if local numbers increase, global extinction risk may grow, and even if new plants arrive, unique ecosystems may weaken. Even if an ecosystem appears abundant on the surface, the relationships within it may become unstable.

The fact that climate change does not necessarily reduce plant diversity in every case reveals nature’s resilience, but also exposes nature’s vulnerability. Plants try to move and adapt in whatever ways are possible. But if the speed of change is too fast, the barriers created by humans are too numerous, and suitable habitats shrink too quickly, that adaptation reaches its limits. Movement is part of hope, but it is not a sufficient answer.

The plant world of the future will be different from the one we know today. The composition of forests will change, plant zones in mountains will shift, and the flora around cities and farmland will also transform. Some changes are unavoidable, some must be prevented, and some must be managed. Conservation in the age of climate change is becoming less about holding nature in the past and more about expanding the conditions under which life can survive.

In the end, the question raised by this discussion is simple. It is not merely how many plant species will remain, but which plants will survive where, and in what relationships. Behind the scene of increasing local diversity, which forms of life are disappearing? Is nature newly filled truly healthy nature? To answer these questions, we must look beyond numbers and see the ecosystem itself.

Climate change does not necessarily reduce plant diversity in every case. But that is no reason to feel reassured. Climate change does not simply empty nature; it rearranges nature in unfamiliar ways. Within that rearrangement, some forms of life gain opportunities, while others eventually lose their place. The work of protecting the future of nature begins with learning to read that difference.

Science, May 2026, Climate-induced range shifts support local plant diversity but don’t reduce extinction risk