The temperature, rainfall, seasonal variation and frequency of frost days in a given region provide crucial information for plants that helps them thrive. As a result, the plants found in a location can tell us much about its climate. This is why the world’s climatic zones can be categorized based on the type of vegetation they support, effectively creating a botanic perspective of the Earth.
Despite the astonishing diversity of over 391,000 vascular plant species, these can be classified into 14 distinct “growth forms”. From a botanical viewpoint, the world is split not into geopolitical regions, but habitats that are more or less appropriate for specific plants like trees, succulents or grasses. Some locations are prime territories for towering evergreen trees, while others are more conducive for resilient grass varieties and cacti.
A group of German and Swiss researchers produced a map of the world’s climate from the lens of plants. They developed projected estimations showing potential alterations in botanical habitats due to climate change, utilising climate and plant-evolution models.
Like a cold climate, Ireland’s weather conditions are ideal for shrubs and deciduous trees, needle-leaved flora such as pines, and herbs and grasses that prefer cooler temperatures. On the other hand, equatorial nations such as the Democratic Republic of the Congo and Ecuador offer perfect habitats for climbing plants and evergreen trees, typical of their rainforests.
Climate change is expected to cause a shift in these vegetative realms. Plant reactions to climate alterations may not always be consistent with simple climate change indicators. For instance, predictions suggest that the Sahara desert will become increasingly hotter, but since a huge portion of this land is already ill-suited for plant growth, this may not significantly affect the local plant life.
However, temperature alterations in the polar regions could transform the grass-dominated tundra into an area suitable for trees and shrubs, relocating the remaining tundra vegetation to the absolute northern edges of the Arctic. Interactions between altering climate and plant populations are not entirely dependent on the changes themselves but are also influenced by where these climate transitions originate and other plant-growth restrictions like nutrients.
Several climate zones in the future will maintain conditions favourable for the broad spectrum of flora, comparable to the environment seen today. However, these suitable conditions will begin to shift, and it is projected that there will be areas on our planet where the climate will be unlike anything experienced in the current era from a plant’s perspective.
These unique climatic conditions might be seen in regions such as southeast South America and Australia. The conditions in these areas are predicted to evolve from being ideal for a variety of plant species to becoming conducive primarily for plant types that do not routinely coexist. These transformed conditions could lead to the formation of bizarre and new ecosystems.
Looking to the future, certain combinations of climatic conditions could result in the global extinction of existing plant-climates. The species that presently thrive in these climates are also at a substantial risk of extinction. If the climate becomes untenable for the distinct species that thrive in these vanishing zones, efforts towards conservation and restoration could become extremely challenging, if not unattainable.
In light of the massive forecasted shifts in plant-environments over the following five decades, what measures can be implemented to mitigate and adapt to these transitions? Substantial reductions in the emission of greenhouse gases from our damaging course will noticeably decrease the disruption to plant climates. Consequently, actions to mitigate climate change are essential for preserving biodiversity and facilitating the adaptation of ecosystems to the changing atmosphere.
Also vital will be conservation and restoration efforts at a landscape scale, which provide favourable conditions for plant species to move in sync with the changing climates. The preservation of small isolated patches will increasingly prove problematic. It’s crucial for ecologists to focus not only on predicting where favourable plant climates may arise, but also on understanding how plant communities might reorganise under changing conditions and how these unusual plant climates and their accompanying ecosystems might operate.
The influence of climate on human life is largely determined by the flourishing of divergent ecosystems in a variety of climatic conditions. As the conditions favourable for plant growth and survival begin to alter, our intervention will be crucial for them to withstand, observe, and reorganise in the emerging climates.
Professor Yvonne Buckley, the joint director of the Co-Centre for Climate + Biodiversity + Water based at Trinity College Dublin, is one who shares these views.
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